Recent publications

  1. Merkouris, A., Chorianopoulou, B., Chorianopoulos, K., and Chrissikopoulos, V. 2019. Understanding the Notion of Friction Through Gestural Interaction with a Remotely Controlled Robot. Journal of Science Education and Technology 0, 0.
    Embodied interaction with tangible interactive objects can be beneficial for introducing abstract scientific concepts, especially for young learners. Nevertheless, there is limited comparative evaluation of alternative interaction modalities with contemporary educational technology, such as tablets and robots. In this study, we explore the effects of touch and gestural interaction with a tablet and a robot, in the context of a primary education physics course about the notion of friction. For this purpose, 56 students participated in a between-groups study that involved four computationally enhanced interventions which correspond to different input and output modalities, respectively: (1) touch-virtual, (2) touch-physical, (3) hand gesture-virtual, and (4) hand gesture-physical. We measured students’ friction knowledge and examined their views. We found that the physical conditions had greater learning impact concerning friction knowledge compared to the virtual way. Additionally, physical manipulation benefited those learners who had misconceptions or limited initial knowledge about friction. We also found that students who used the more familiar touchscreen interface demonstrated similar learning gains and reported higher usability compared to those using the hand-tilt interface. These findings suggest that user interface familiarity should be carefully balanced with user interface congruency, in order to establish accessibility to a scientific concept in a primary education context.
  2. Garneli, V. and Chorianopoulos, K. 2018. Programming video games and simulations in science education: exploring computational thinking through code analysis. Interactive Learning Environments 26, 3, 386–401.
    Various aspects of computational thinking (CT) could be supported by educational contexts such as simulations and video-games construction. In this field study, potential differences in student motivation and learning were empirically examined through students’ code. For this purpose, we performed a teaching intervention that took place over five weeks, with two-hour sessions per week, plus two more weeks for the pretest and post-test projects. Students were taught programming concepts through a science project; one group represented the function of a basic electric circuit by creating a simulation, while the other group represented the same function by creating a video game in which a player should achieve a score in order to win. Video game construction resulted in projects with higher CT skills and more primitives, as measured through projects’ code analysis. Moreover, the video-game context seems to better motivate students for future engagement with computing activities.
  3. Chorianopoulos, K. 2018. A Taxonomy of Asynchronous Instructional Video Styles. The International Review of Research in Open and Distributed Learning 19, 1.
    Many educational organizations are employing instructional video in their pedagogy, but there is limited understanding of the possible presentation styles. In practice, the presentation style of video lectures ranges from a direct recording of classroom teaching with a stationary camera and screencasts with voice-over, up to highly elaborate video post-production. Previous work evaluated the effectiveness of several presentation styles, but there has not been any consistent taxonomy, which would have made comparisons and meta-analyses possible. In this article, we surveyed the research literature and we examined contemporary video-based courses, which have been produced by diverse educational organizations and teachers across various academic disciplines. We organized video lectures in two dimensions according to the level of human presence and according to the type of instructional media. In addition to organizing existing video lectures in a comprehensive way, the proposed taxonomy offers a design space that facilitates the choice of a suitable presentation style, as well as the preparation of new ones.

All publications

News

Mar 14, 2018 Got tenured at the rank of assistant professor! :fireworks:
Oct 15, 2017 Selected to teach at the MSc on Mobile and Ubiquitous Computing at the Hellenic Open University
Jun 7, 2017 Post-graduate student Varvara Garneli successfully defended PhD thesis 🎓
Apr 9, 2017 Accepted invitation to serve as publicity co-chair for the IEEE Pervasive Computing 2018 conference 📢
Sep 14, 2016 Self-published a book on making of interactive systems! 📖
Sep 5, 2014 General co-chair of the IFIP International Conference on Entertainment Computing 2015

Selected

  1. Chorianopoulos, K. 2018. A Taxonomy of Asynchronous Instructional Video Styles. The International Review of Research in Open and Distributed Learning 19, 1.
    Many educational organizations are employing instructional video in their pedagogy, but there is limited understanding of the possible presentation styles. In practice, the presentation style of video lectures ranges from a direct recording of classroom teaching with a stationary camera and screencasts with voice-over, up to highly elaborate video post-production. Previous work evaluated the effectiveness of several presentation styles, but there has not been any consistent taxonomy, which would have made comparisons and meta-analyses possible. In this article, we surveyed the research literature and we examined contemporary video-based courses, which have been produced by diverse educational organizations and teachers across various academic disciplines. We organized video lectures in two dimensions according to the level of human presence and according to the type of instructional media. In addition to organizing existing video lectures in a comprehensive way, the proposed taxonomy offers a design space that facilitates the choice of a suitable presentation style, as well as the preparation of new ones.
  2. Chorianopoulos, K. and Talvis, K. 2016. Flutrack.org: Open-source and linked data for epidemiology. Health Informatics Journal 22, 4, 962–974.
    Epidemiology has made advances, thanks to the availability of real-time surveillance data and by leveraging the geographic analysis of incidents. There are many health information systems that visualize the symptoms of influenza-like illness on a digital map, which is suitable for end-users, but it does not afford further processing and analysis. Existing systems have emphasized the collection, analysis, and visualization of surveillance data, but they have neglected a modular and interoperable design that integrates high-resolution geo-location with real-time data. As a remedy, we have built an open-source project and we have been operating an open service that detects flu-related symptoms and shares the data in real-time with anyone who wants to built upon this system. An analysis of a small number of precisely geo-located status updates (e.g. Twitter) correlates closely with the Google Flu Trends and the Centers for Disease Control and Prevention flu-positive reports. We suggest that public health information systems should embrace an open- source approach and offer linked data, in order to facilitate the development of an ecosystem of applications and services, and in order to be transparent to the general public interest.
  3. Chorianopoulos, K. 2014. Community-based Pedestrian Mapmaking. The Journal of Community Informatics 10, 3.
    Despite the widespread use of highly accurate digital maps on desktop and mobile computers, cartography has over-emphasized the needs of land use and car navigation. Previous work has considered data analysis and path finding techniques, but there has been limited consideration of the subjective perceptions in pedestrian mapmaking. Besides the immediate benefit to pedestrians, a pragmatic understanding of walking paths might facilitate urban planning and design, which is usually based on cartography. Finally, we demonstrate how the tools and techniques of cartography have influenced the image of the city with references to past and ongoing efforts.
  4. Chorianopoulos, K. 2013. Collective intelligence within web video. Human-centric Computing and Information Sciences 3, 1, 10.
    We present a user-based approach for detecting interesting video segments through simple signal processing of users collective interactions with the video player (e.g., seek/scrub, play, pause). Previous research has focused on content-based systems that have the benefit of analyzing a video without user interactions, but they are monolithic, because the resulting key-frames are the same regardless of the user preferences. We developed the open-source SocialSkip system on a modular cloud-based architecture and analyzed hundreds of user interactions within difficult video genres (lecture, how-to, documentary) by modeling them as user interest time series. We found that the replaying activity is better than the skipping forward one in matching the semantics of a video, and that all interesting video segments can be found within a factor of two times the average user skipping step from the local maximums of the replay time series. The concept of simple signal processing of implicit user interactions within video could be applied to any type of Web video system (e.g., TV, desktop, tablet), in order to improve the user navigation experience with dynamic and personalized key-frames.
  5. Koutsourelakis, C. and Chorianopoulos, K. 2010. Icons in mobile phones Comprehensibility differences between older and younger users. Information Design Journal 18, 1, 22–35.
    Mobile phones have become a ubiquitous information and telecommunication terminal used by diverse age groups. Despite research findings that indicate the special needs and skills of senior citizens, contemporary handsets offer limited consideration for them. We investigated whether typical mobile phone icons are suitable for older users, as measured through unaided icon comprehension. For this purpose, we studied 38 users and evaluated 25 icons, which we captured from five different handsets. It was found that there are significant differences in icon comprehension performance between older and younger mobile phone users. We conclude that designers of mobile phone icons have to regard older user groups differently and we describe the qualities of icons suitable to each one of the age groups. Finally, we highlight the need for additional similar research in different ethnic and cultural groups.
  6. Chorianopoulos, K. 2008. User Interface Design Principles for Interactive Television Applications. International Journal of Human-Computer Interaction 24, 6, 556–573.
    Interactive Television (ITV) applications gratify entertainment needs and leisure activities in a relaxed domestic context. Then, the mentality of efficiency and task completion implied by many user interface heuristics may not be suitable for design and expert evaluation of ITV. In line with the contemporary movement towards the design of the user experience of computing systems, a set of design principles for ITV applications has been developed. Instead of information technology, the field of communication science was explored, which has accumulated an extensive theory of TV usage and viewer behavior. For the empirical validation, the principles were employed in the design of an interactive music TV application. The results suggest that a small set of generic principles could support the systematic design of ITV applications and produce a design rationale that is traceable and comparable to alternative solutions, during the process of early product development. In addition, the principles could be refined into specific guidelines and further employed to support expert evaluation techniques.
  7. Chorianopoulos, K. and Spinellis, D. 2006. User interface evaluation of interactive TV: a media studies perspective. Universal Access in the Information Society 5, 2, 209–218.
    A diverse user population employs interactive TV (ITV) applications in a leisure context for entertainment purposes. The traditional user interface (UI) evaluation paradigm involving efficiency and task completion may not be adequate for the assessment of such applications. In this paper, we argue that unless ITV applications are evaluated with consideration for the ordinary TV viewer, they are going to be appropriate only for the computer literate user, thus excluding the TV audience from easy access to information society services. The field of media studies has accumulated an extensive theory of TV and associated methods. We applied the corresponding findings in the domain of ITV to examine how universal access to ITV applications can be obtained. By combining these results with emerging affective quality theories for interactive products, we propose a UI evaluation framework for ITV applications.

Books

  1. Cesar, P. and Chorianopoulos, K. 2009. The Evolution of TV Systems, Content, and Users Toward Interactivity. .
    Interactive TV research spans across a rather diverse body of scientific subfields. Research articles have appeared in several venues, such as multimedia, HCI, CSCW, UIST, user modeling, media and communication sciences. In this study, we explore the state-of-the-art and consider two basic issues: What is interactive TV research? Can it help us reinvent the practices of authoring, delivering, and watching TV? For this purpose, we have reviewed the research literature, as well as the industrial developments and identified three concepts that provide a high-level taxonomy of interactive TV research: (1) content editing, (2) content sharing, and (3) content control. We propose this simple taxonomy (edit-share-control) as an evolutionary step over the established hierarchical produce-deliver-consume paradigm. Moreover, we demonstrate how each disciplinary effort has contributed to and why the full potential of interactive TV has not yet been fulfilled. Finally, we describe how interdisciplinary approaches could provide solutions to some notable contemporary research issues.

Edited books

  1. Willis, K.S., Roussos, G., Chorianopoulos, K., and Struppek, M., eds. 2010. Shared Encounters. Springer.
    Every day we share encounters with others as we inhabit the space around us. In offering insights and knowledge on this increasingly important topic, this book introduces a range of empirical and theoretical approaches to the study of shared encounters. It highlights the multifaceted nature of collective experience and provides a deeper understanding of the nature and value of shared encounters in everyday life.Divided into four sections, each section comprises a set of chapters on a different topic and is introduced by a key author in the field who provides an overview of the content. The book itself is introduced by Paul Dourish, who sets the theme of shared encounters in the context of technological and social change over the last fifteen years. The four sections that follow consider the characteristics of shared encounters and describe how they can be supported in different settings: the first section, introduced by Barry Brown, looks at shared experiences. George Roussos, in the second section, presents playful encounters. Malcolm McCulloch introduces the section on spatial settings and ’ last but not least ’ Elizabeth Churchill previews the topic of social glue. The individual chapters that accompany each part offer particular perspectives on the main topic and provide detailed insights from the author’s own research background. A valuable reference for anyone designing ubiquitous media, mobile social software and LBS applications, this volume will also be useful to researchers, students and practitioners in fields ranging from computer science to urban studies.
  2. Cesar, P., Geerts, D., and Chorianopoulos, K., eds. 2009. Social Interactive Television: Immersive Shared Experiences and Perspectives (Premier Reference Source). IGI Global.
    Television, since its invention, has been considered to be a social link between people. Continually enhanced by innovation, the next frontier for this technological phenomenon will focus on the actual natural capabilities of the medium. Social Interactive Television: Immersive Shared Experiences and Perspectives combines academic and industry research to provide the first publication of its kind to discuss the future emergence of experiences and services through interactive television. Concentrating on system and interaction design, as well as evaluation methods that focus on social experiences around interactive television, this book provides practitioners, academicians, researchers, and developers with the most relevant, current, and interesting findings on the topic.
  3. Eckardt, F., Geelhaar, J., Colini, L., Willis, K.S., Chorianopoulos, K., and Hennig, R., eds. 2008. MEDIACITY. Situations, Practices and Encounters. Frank & Timme GmbH.
    MEDIACITY – Situations, Practices and Encounters investigates how the social settings and spaces of the city are created, experienced and practiced through the use and presence of new media. It takes the position that new media enables different settings, practices and behaviours to occur in urban space. Contributions from academics, practitioners and activists from disciplines such as Media Studies, Architecture, Urban Studies, Cultural and Urban Geography and Sociology present a critical reflection on the processes, methods and impacts of technologies in urban space.
  4. Cesar, P., Chorianopoulos, K., and Jensen, J.F., eds. 2007. Interactive TV: A Shared Experience. Springer.
    This book constitutes the refereed proceedings of the 5th European Conference on Interactive Television, EuroITV 2007, held in Amsterdam, The Netherlands in May 2007. The 24 revised full papers were carefully reviewed and selected from 80 submissions. The volume combines papers from academia and industry covering a wide range of areas such as media studies, audiovisual design, multimedia, human-computer interaction, and management. The papers are organized in topical sections on social TV systems, user studies, the future of TV, social TV evaluation, personalization, and mobile TV.
  5. Lekakos, G., Chorianopoulos, K., and Doukidis, G. and, eds. 2007. Interactive Digital Television: Technologies and Applications. IGI Publishing.
    This book constitutes the refereed proceedings of the 5th European Conference on Interactive Television, EuroITV 2007, held in Amsterdam, The Netherlands, May 2007. The volume covers a wide range of areas such as media studies, audiovisual design, multimedia, HCI, and management. The papers are organized in topical sections on social TV systems, user studies, the future of TV, social TV evaluation, personalization, and mobile TV.

Edited journals

  1. Giannakos, M.N., Chorianopoulos, K., Ronchetti, M., Szegedi, P., and Teasley, S. 2014. Video-Based Learning and Open Online Courses. International Journal of Emerging Technologies in Learning (iJET) 9, 1, 4–7.
    In this article, we provide an overview of the emerging research area on Analytics and Video-Based Learning. Although there are many and diverse ways of designing learning videos, there is limited understanding of the efficacy and usefulness of each method. Therefore, we survey the state-of-the-art in the design, development and evaluation of open and video-based courses. The main objective is to highlight the importance and benefits of analytics and to support instructors with the appropriate resources for improving the use of their courses. This can be achieved by combining and analyzing learners’ interactions with other available data obtained from learners, as such video analytics open new avenues for research on open and video-based courses. In addition to the guidelines for video-based analytics we have selected five indicative case-studies that provide in-depth analysis..
  2. Chorianopoulos, K. and Geerts, D. 2011. Introduction to User Experience Design for TV Apps. Entertainment Computing.
    In this introduction to the special issue of Entertainment Computing on the new TV landscape, we introduce interactive television (iTV) research as one of the pillars in the field of entertainment computing. Although entertainment computing has been associated mainly with video-games, there is also more than a couple of decades’ research in computer applications for television. Contemporary infrastructures have been converging towards mature development platforms, but there are still several user experience issues in TV applications (TV Apps). Here, we explore significant contributions to interactive TV, and we provide directions for further research in user experience design for TV Apps.
  3. Yu, Z., Lugmayr, A., Chorianopoulos, K., and Mei, T. 2010. Introduction to the special issue on multimedia intelligent services and technologies. Multimedia Systems 16, 4-5, 215–217.
    The rapid development of digital media technologies enables the emergence of novel media content types for eCommerce, eEducation, and digital entertainment. On the other hand, the advances in communication and micro-electronics have led to a transition from traditional personal computer-centric to more intuitive human-centric information access modes and the embedment of computer systems throughout the natural environment. This type of computation is generally known as Pervasive or Ubiquitous Computing. It can also be referred to as ambient intelligence, or talking about media environments as ambient media. It allows a person to use a variety of devices and sensor networks seamlessly embedded throughout our daily life, such as personal digital assistant (PDA), smart electronics, sensors, as well as personal computer, to access those media contents. The combination of these two trends (emergence of media and pervasive computing) holds the potential of providing a user with seamless and ubiquitous access to rich and dynamic mul- timedia resources from anywhere and anytime.
  4. Chorianopoulos, K. 2008. Personalized and mobile digital TV applications. Multimedia Tools and Applications 36, 1-2, 1–10.
    The introduction of mobile and broadband networks in complement to the existing satellite, cable, and terrestrial platforms, opens new opportunities for interactive TV (ITV) applications. In addition, the widespread adoption of multimedia computing has enabled the processing of TV content on personal devices such as mobile phones and PCs. The above developments raise novel issues and require the adoption of new multimedia standards and application frameworks. In particular, the explosion in the amount of available TV channels over digital television platforms (broadcast or internet protocol) makes searching and locating interesting content a cumbersome task. In this context, personalization research is concerned with the adaptation of content (e.g. movies, news, advertisements). Personalization is achieved with the employment of algorithms and data collection schemes that predict and recommend to television viewers content that match their interests. In addition, the distribution of TV content to mobile devices over broadband wireless raises the issue of video quality. Video quality depends on many aspects of the video encoding systems, such as bit rate and algorithms that model human perception of video on small screens. In this article, we examine contemporary research in personalized and mobile digital TV applications. Moreover, we present a critical survey of the most prominent research and provide directions for further research in personalized and mobile digital TV (DTV) applications.
  5. Chorianopoulos, K. and Lekakos, G. 2008. Introduction to Social TV: Enhancing the Shared Experience with Interactive TV. International Journal of Human-Computer Interaction 24, 2, 113–120.
    Previous research on the social impact of communication technologies has followed two distinct directions and has considered independently either the interpersonal communication or the mass communication. In this context, the human–computer interaction aspects of integrated media and social communication are examined. The design of Social TV systems that support interpersonal communication, which is motivated by mass media consumption and which takes place within colocated groups or over distance, is explored. In terms of the temporal dimension, Social TV might be synchronous, which happens in real time, or asynchronous, which happens with a time difference. This article provides an overview of research findings and outlines evaluation methods and user requirements for usability and sociability in interactive TV.
  6. Cesar, P., Chorianopoulos, K., and Jensen, J.F. 2008. Social television and user interaction. Computers in Entertainment 6, 1, 1.
    At first glance, the notion of social interactive television seems to be a tautology. Television watching has always been a social activity. People watch television together in their living rooms, and outside their homes they talk about last night’s football match; and even call each other to recommend an interesting program. Unfortunately, until recently, research on social interactive television has been scarce. One limiting factor for the development of innovative services for the home is the interactive technology behind user interaction, which was limited to the remote control. Fortunately, a number of studies concentrate on extending interactive methods, for example by using contextual information. This article reviews the state of the art in these two directions: the social aspects of television and user interaction. We conclude with a research agenda for further research, which might transform current interactive television services into shared experiences.
  7. Cesar, P., Bulterman, D.C.A., Chorianopoulos, K., and Jensen, J.F. 2008. Multimedia systems, languages, and infrastructures for interactive television. Multimedia Systems 14, 2, 71–72.
  8. Chorianopoulos, K. and Lekakos, G. 2007. Methods and Applications in Interactive Broadcasting. Journal of Virtual Reality and Broadcasting 4, 8.
    Interactive TV technology has been addressed in many previous works, but there is sparse research on the topic of interactive content broadcasting and how to support the production process. In this article, the interactive broadcasting process is broadly defined to include studio technology and digital TV applications at consumer set-top boxes. In particular, augmented reality studio technology employs smart-projectors as light sources and blends real scenes with interactive computer graphics that are controlled at end-user terminals. Moreover, TV producer-friendly multimedia authoring tools empower the development of novel TV formats. Finally, the support for user-contributed content raises the potential to revolutionize the hierarchical TV production process, by introducing the viewer as part of content delivery chain.
  9. Chorianopoulos, K. and Lekakos, G. 2007. Learn and play with interactive TV. Computers in Entertainment 5, 2, 4.
    Despite the criticism concerning the value of TV content, research reveals several worthwhile aspects – one of them is the opportunity to learn. In this article we explore the characteristics of interactive TV applications that facilitate education and interactive entertainment. In doing so we analyze research methods and empirical results from experimental and field studies. The findings suggest that interactive TV applications provide support for education and entertainment for children and young people, as well as continuous education for all. In particular, interactive TV is especially suitable for (1) informal learning and (2) for engaging and motivating its audience. We conclude with an agenda for future interactive TV research in entertainment and education.

Journals

  1. Merkouris, A., Chorianopoulou, B., Chorianopoulos, K., and Chrissikopoulos, V. 2019. Understanding the Notion of Friction Through Gestural Interaction with a Remotely Controlled Robot. Journal of Science Education and Technology 0, 0.
    Embodied interaction with tangible interactive objects can be beneficial for introducing abstract scientific concepts, especially for young learners. Nevertheless, there is limited comparative evaluation of alternative interaction modalities with contemporary educational technology, such as tablets and robots. In this study, we explore the effects of touch and gestural interaction with a tablet and a robot, in the context of a primary education physics course about the notion of friction. For this purpose, 56 students participated in a between-groups study that involved four computationally enhanced interventions which correspond to different input and output modalities, respectively: (1) touch-virtual, (2) touch-physical, (3) hand gesture-virtual, and (4) hand gesture-physical. We measured students’ friction knowledge and examined their views. We found that the physical conditions had greater learning impact concerning friction knowledge compared to the virtual way. Additionally, physical manipulation benefited those learners who had misconceptions or limited initial knowledge about friction. We also found that students who used the more familiar touchscreen interface demonstrated similar learning gains and reported higher usability compared to those using the hand-tilt interface. These findings suggest that user interface familiarity should be carefully balanced with user interface congruency, in order to establish accessibility to a scientific concept in a primary education context.
  2. Chorianopoulos, K. 2018. A Taxonomy of Asynchronous Instructional Video Styles. The International Review of Research in Open and Distributed Learning 19, 1.
    Many educational organizations are employing instructional video in their pedagogy, but there is limited understanding of the possible presentation styles. In practice, the presentation style of video lectures ranges from a direct recording of classroom teaching with a stationary camera and screencasts with voice-over, up to highly elaborate video post-production. Previous work evaluated the effectiveness of several presentation styles, but there has not been any consistent taxonomy, which would have made comparisons and meta-analyses possible. In this article, we surveyed the research literature and we examined contemporary video-based courses, which have been produced by diverse educational organizations and teachers across various academic disciplines. We organized video lectures in two dimensions according to the level of human presence and according to the type of instructional media. In addition to organizing existing video lectures in a comprehensive way, the proposed taxonomy offers a design space that facilitates the choice of a suitable presentation style, as well as the preparation of new ones.
  3. Garneli, V. and Chorianopoulos, K. 2018. Programming video games and simulations in science education: exploring computational thinking through code analysis. Interactive Learning Environments 26, 3, 386–401.
    Various aspects of computational thinking (CT) could be supported by educational contexts such as simulations and video-games construction. In this field study, potential differences in student motivation and learning were empirically examined through students’ code. For this purpose, we performed a teaching intervention that took place over five weeks, with two-hour sessions per week, plus two more weeks for the pretest and post-test projects. Students were taught programming concepts through a science project; one group represented the function of a basic electric circuit by creating a simulation, while the other group represented the same function by creating a video game in which a player should achieve a score in order to win. Video game construction resulted in projects with higher CT skills and more primitives, as measured through projects’ code analysis. Moreover, the video-game context seems to better motivate students for future engagement with computing activities.
  4. Garneli, V., Giannakos, M., and Chorianopoulos, K. 2017. Serious games as a malleable learning medium: The effects of narrative, gameplay, and making on students’ performance and attitudes. British Journal of Educational Technology 48, 3, 842–859.
    Research into educational technology has evaluated new computer-based systems as tools for improving students’ academic performance and engagement. Serious games should also be considered as an alternative pedagogical medium for attracting students with different needs and expectations. In this field study, we empirically examined different forms of serious-game use for learning on learning performance and attitudes of eighty 13-year-old students in the first grade of middle school. Divided into four groups of 20 students, each group practiced with a maths video game in three ways. The first group played the storytelling maths game, the second played the same game but with no story and the third played and modified the video game. Finally, a control group practised in a paper-based (traditional) way by solving exercises. Although only minor differences in learning performance were identified, we found significant differences in the attitudes of the students toward learning through the video game. Students who are not motivated by conventional paper-based assignments might be engaged better with the use of a video game. Our findings suggest that video game pedagogy could provide malleable learning for different groups of students using methods that move beyond the conventional tool-based approach.
  5. Kapenekakis, I. and Chorianopoulos, K. 2017. Citizen science for pedestrian cartography: collection and moderation of walkable routes in cities through mobile gamification. Human-centric Computing and Information Sciences 7, 1, 10.
    Digital geographical maps can be regarded as a user interface for understanding and navigating the city. Nevertheless, contemporary digital maps over-emphasize the needs of motor vehicles. Pedestrian routes have only been considered as an add-on option in existing digital maps and the respective data collection has not been performed in the field. In this article, we present a mobile application that employs gamification as a means to engage users to collect pragmatic data about walkable routes, which are then processed with the goal of creating a new kind of pedestrian-friendly cartography. Besides the technical infrastructure for collecting and filtering the route traces, the main challenge in user-generated walkable routes is the identification of malicious data, which should be rejected, as well as the rewarding of constructive behavior through peer-review. For this purpose, the mobile application employs a point system in order to identify and discourage the submission of bad routes. A longitudinal field study of the mobile application confirmed that gamification facilitates effective data collection for producing pedestrian cartography even with few users and demonstrated that gamification infuses a shared responsibly about the quality of data collection. The visualization of the pedestrian-generated data on a map required a partially manual process, thus, further research should explore the gamification of the data visualization part, too.
  6. Moholdt, T., Weie, S., Chorianopoulos, K., Wang, A.I., and Hagen, K. 2017. Exergaming can be an innovative way of enjoyable high-intensity interval training. BMJ Open Sport & Exercise Medicine 3, 1, e000258.
    Objectives Exergames can replace sedentary time spent on computer gaming with physical activity. Previous research has found exergaming to elicit light-to-moderate exercise intensity. Our primary aim was to examine the exercise intensity of a newly developed biking exergame. Methods Eight males (23.9±0.6 years) played the exergame (PLAY) and walked (WALK) on three separate occasions, with the condition counterbalanced and in random sequence within each day. They were asked to PLAY and WALK for a minimum of 15 min and then continue for as long as they wanted. We measured heart rate (HR), activity duration, caloric expenditure and subject-rated exertion and enjoyment (based on 0–10 Visual Analogue Scale, VAS). We used an average of each outcome variable across the 3 days in the analysis. Results The average intensity during PLAY (73%±10% of HRmax) was significantly higher than that during WALK (57%±7% of HRmax, p=0.01). Participants spent 12.5±5.3 min at 80%–89% of HRmax and 5.5±4.6 min at ≥90% of HRmax during PLAY, whereas intensity during WALK was ≤72% of HRmax. The duration of PLAY was 44.3±0.7 min and of WALK 17.0±0.7 min (p=0.01). The relative energy expenditure during PLAY was 7.6±0.7 kcal/min and during WALK 6.2±0.3 kcal/min (p\textless0.01). The enjoyment of PLAY (VAS 8.7±0.1) was higher than that of WALK (VAS 3.9±1.8, p=0.01). Conclusions Exergaming can be an innovative way of enjoyable high-intensity training.
  7. Merkouris, A., Chorianopoulos, K., and Kameas, A. 2017. Teaching Programming in Secondary Education Through Embodied Computing Platforms: Robotics and Wearables. ACM Transactions on Computing Education 17, 2, 1–22.
    Pedagogy has emphasized that physical representations and tangible interactive objects benefit learning especially for young students. There are many tangible hardware platforms for introducing computer programming to children, but there is limited comparative evaluation of them in the context of a formal classroom. In this work, we explore the benefits of learning to code for tangible computers, such as robots and wearable computers, in comparison to programming for the desktop computer. For this purpose, 36 students participated in a within-groups study that involved three types of target computer platform tangibility. 1) desktop, 2) wearable, and 3) robotic. We employed similar blocks-based visual programming environments, and we measured emotional engagement, attitudes, and computer programming performance. We found that students were more engaged by and had a higher intention of learning programming with the robotic rather than the desktop computer. Furthermore, tangible computing platforms, either robot or wearable, did not affect the students’ performance in learning basic computational concepts (e.g., sequence, repeat, and decision). Our findings suggest that computer programming should be introduced through multiple target platforms (e.g., robots, smartphones, wearables) to engage children.
  8. Leftheriotis, I., Chorianopoulos, K., and Jaccheri, L. 2016. Design and implement chords and personal windows for multi-user collaboration on a large multi-touch vertical display. Human-centric Computing and Information Sciences 6, 1, 14.
    Co-located collaboration on large vertical screens has become technically feasible, but users are faced with increased effort, or have to wear intrusive personal identifiers. Previous research on co-located collaboration has assumed that all users perform exactly the same task (e.g., moving and resizing photos), or that they negotiate individual actions in turns. However, there is limited user interface software that supports simultaneous performance of individual actions during shared tasks (Fig. 1a). As a remedy, we have introduced multi-touch chords (Fig. 1b) and personal action windows (Fig. 1c) for co-located collaboration on a large multi-touch vertical display. Instead of selecting an item in a fixed menu by reaching for it, users work simultaneously on shared tasks by means of personal action windows, which are triggered by multi-touch chords performed anywhere on the display. In order to evaluate the proposed technique with users, we introduced an experimental task, which stands for the group dynamics that emerge during shared tasks on a large display. A grounded theory analysis of users’ behaviour provided insights into established co-located collaboration topics, such as conflict resolution strategies and space negotiation. The main contribution of this work is the design and implementation of a novel seamless identification and interaction technique that supports diverse multi-touch interactions by multiple users: multi-touch chord interaction along with personal action windows.
  9. Chorianopoulos, K. and Talvis, K. 2016. Flutrack.org: Open-source and linked data for epidemiology. Health Informatics Journal 22, 4, 962–974.
    Epidemiology has made advances, thanks to the availability of real-time surveillance data and by leveraging the geographic analysis of incidents. There are many health information systems that visualize the symptoms of influenza-like illness on a digital map, which is suitable for end-users, but it does not afford further processing and analysis. Existing systems have emphasized the collection, analysis, and visualization of surveillance data, but they have neglected a modular and interoperable design that integrates high-resolution geo-location with real-time data. As a remedy, we have built an open-source project and we have been operating an open service that detects flu-related symptoms and shares the data in real-time with anyone who wants to built upon this system. An analysis of a small number of precisely geo-located status updates (e.g. Twitter) correlates closely with the Google Flu Trends and the Centers for Disease Control and Prevention flu-positive reports. We suggest that public health information systems should embrace an open- source approach and offer linked data, in order to facilitate the development of an ecosystem of applications and services, and in order to be transparent to the general public interest.
  10. Giannakos, M.N., Chorianopoulos, K., and Chrisochoides, N. 2015. Making sense of video analytics: Lessons learned from clickstream interactions, attitudes, and learning outcome in a video-assisted course. The International Review of Research in Open and Distributed Learning 16, 1.
    Online video lectures have been considered an instructional media for various pedagogic approaches, such as the flipped classroom and open online courses. In comparison to other instructional media, online video affords the opportunity for recording student clickstream patterns within a video lecture. Video analytics within lecture videos may provide insights into student learning performance and inform the improvement of video-assisted teaching tactics. Nevertheless, video analytics are not accessible to learning stakeholders, such as researchers and educators, mainly because online video platforms do not broadly share the interactions of the users with their systems. For this purpose, we have designed an open-access video analytics system for use in a video-assisted course. In this paper, we present a longitudinal study, which provides valuable insights through the lens of the collected video analytics. In particular, we found that there is a relationship between video navigation (repeated views) and the level of cognition/thinking required for a specific video segment. Our results indicated that learning performance progress was slightly improved and stabilized after the third week of the video-assisted course. We also found that attitudes regarding easiness, usability, usefulness, and acceptance of this type of course remained at the same levels throughout the course. Finally, we triangulate analytics from diverse sources, discuss them, and provide the lessons learned for further development and refinement of video-assisted courses and practices.
  11. Karydis, I., Avlonitis, M., Chorianopoulos, K., and Sioutas, S. 2014. Identifying Important Segments in Videos: A Collective Intelligence Approach. International Journal on Artificial Intelligence Tools 23, 02.
    This work studies collective intelligence behavior of Web users that share and watch video content. Accordingly, it is proposed that the aggregated users’ video activity exhibits characteristic patterns. Such patterns may be used in order to infer important video scenes leading thus to collective intelligence concerning the video content. To this end, experimentation is based on users’ interactions (e.g., pause, seek/scrub) that have been gathered in a controlled user experiment with information-rich videos. Collective information seeking behavior is then modeled by means of the corresponding probability distribution function. Thus, it is argued that the bell-shaped reference patterns are shown to significantly correlate with predefined scenes of interest for each video, as annotated by the users. In this way, the observed collective intelligence may be used to provide a video-segment detection tool that identifies the importance of video scenes. Accordingly, both a stochastic and a pattern matching appro...
  12. Gkonela, C. and Chorianopoulos, K. 2014. VideoSkip: event detection in social web videos with an implicit user heuristic. Multimedia Tools and Applications 69, 2, 383–396.
    In this paper, we present a user-based event detection method for social web videos. Previous research in event detection has focused on content-based techniques, such as pattern recognition algorithms that attempt to understand the contents of a video. There are few user-centric approaches that have considered either search keywords, or external data such as comments, tags, and annotations. Moreover, some of the user-centric approaches imposed an extra effort to the users in order to capture required information. In this research, we are describing a method for the analysis of implicit users’ interactions with a web video player, such as pause, play, and thirty-seconds skip or rewind. The results of our experiments indicated that even the simple user heuristic of local maxima might effectively detect the same video-events, as indicated manually. Notably, the proposed technique was more accurate in the detection of events that have a short duration, because those events motivated increased user interaction in video hot-spots. The findings of this research provide evidence that we might be able to infer semantics about a piece of unstructured data just from the way people actually use it.
  13. Chorianopoulos, K. 2014. Community-based Pedestrian Mapmaking. The Journal of Community Informatics 10, 3.
    Despite the widespread use of highly accurate digital maps on desktop and mobile computers, cartography has over-emphasized the needs of land use and car navigation. Previous work has considered data analysis and path finding techniques, but there has been limited consideration of the subjective perceptions in pedestrian mapmaking. Besides the immediate benefit to pedestrians, a pragmatic understanding of walking paths might facilitate urban planning and design, which is usually based on cartography. Finally, we demonstrate how the tools and techniques of cartography have influenced the image of the city with references to past and ongoing efforts.
  14. Chorianopoulos, K. and Giannakos, M.N. 2014. Design Principles for Serious Video Games in Mathematics Education: From Theory to Practice. International Journal on Serious Games 1, 3, 51–59.
    There is growing interest in the employment of serious video games in science education, but there are no clear design principles. After surveying previous work in serious video game design, we highlighted the following design principles: 1) engage the students with narrative (hero, story), 2) employ familiar gameplay mechanics from popular video games, 3) engage students into constructive trial and error game-play and 4) situate collaborative learning. As illustrated examples we designed two math video games targeted to primary education students. The gameplay of the math video games embeds addition operations in a seamless way, which has been inspired by that of classic platform games. In this way, the students are adding numbers as part of popular gameplay mechanics and as a means to reach the video game objective, rather than as an end in itself. The employment of well-defined principles in the design of math video games should facilitate the evaluation of learning effectiveness by researchers. Moreover, educators can deploy alternative versions of the games in order to engage students with diverse learning styles. For example, some students might be motived and benefited by narrative, while others by collaboration, because it is unlikely that one type of serious video game might fit all learning styles. The proposed principles are not meant to be an exhaustive list, but a starting point for extending the list and applying them in other cases of serious video games beyond mathematics and learning.
  15. Avlonitis, M. and Chorianopoulos, K. 2014. Video Pulses: User-based modeling of interesting video segments. Advances in Multimedia, 1–9.
    We present a user-based method that detects regions of interest within a video, in order to provide video skims and video summaries. Previous research in video retrieval has focused on content-based techniques, such as pattern recognition algorithms that attempt to understand the low-level features of a video. We are proposing a pulse modeling method, which makes sense of a web video by analyzing users Replay interactions with the video player. In particular, we have modeled the user information seeking behavior as a time series and the semantic regions as a discrete pulse of fixed width. Then, we have calculated the correlation coefficient between the dynamically detected pulses at the local maximums of the user activity signal and the pulse of reference. We have found that users Replay activity significantly matches the important segments in information-rich and visually complex videos, such as lecture, how-to, and documentary. The proposed signal processing of user activity is complementary to previous work in content-based video retrieval and provides an additional user-based dimension for modeling the semantics of a social video on the Web.
  16. Giannakos, M.N., Chorianopoulos, K., Giotopoulos, K.K., and Vlamos, P. 2013. Using Facebook out of habit. Behaviour & Information Technology 32, 6, 594–602.
    This article investigates the uses and gratifications of the popular social networking site Facebook. In the exploratory stage, 70 users generated phrases to describe the manner they used Facebook. Interestingly, some users not only described the uses, but also mentioned how they perceive these uses. These phrases were coded into 14 items and clustered into four factors. The principal component analysis that was conducted in the third stage of the study, which was addressed to 222 Facebook users, verified the validity of the four factors: Social Connection, Social Network Surfing, Wasting Time and Using Applications. Previous user studies on Facebook have examined the immediate social effects of this popular social networking site, but they have not regarded emerging uses of the platform, such as gaming and applications, which do have a social component as a feature and not as a core principle. The ?Wasting Time? factor and the growth of ?Using Applications? factor indicate that Facebook has already become an integral part of daily computing routine, alongside with the rest of the entertainment desktop and web applications.
  17. Giannakos, M.N., Chorianopoulos, K., Inkpen, K., Du, H., and Johns, P. 2013. Understanding childrens behavior in an asynchronous video-mediated communication environment. Personal and Ubiquitous Computing 17, 8, 1621–1629.
    Video-mediated communication (VMC) has become a feasible way to connect people in remote places for work and play. Nevertheless, little research has been done with regard to children and VMC. In this paper, we explore the behavior of a group of children, who exchanged video messages in an informal context. In particular, this paper presents the results of 11-week VMC study of 30 children from the USA and Greece, exploring children’s behavior with the asynchronous video-based messaging tool we developed called VideoPal. In the study, children’s interactions, perceptions, content exchanged and emotions were collected. The results from the analyses highlight that the emotion of happiness dominated in the communication. Moreover, the content included useful personal information and is connected with children’s interactions (e.g., number of views and of recipients). In addition, children generally preferred VideoPal to email because they felt that it was easier and has more fun.
  18. Chorianopoulos, K. 2013. Collective intelligence within web video. Human-centric Computing and Information Sciences 3, 1, 10.
    We present a user-based approach for detecting interesting video segments through simple signal processing of users collective interactions with the video player (e.g., seek/scrub, play, pause). Previous research has focused on content-based systems that have the benefit of analyzing a video without user interactions, but they are monolithic, because the resulting key-frames are the same regardless of the user preferences. We developed the open-source SocialSkip system on a modular cloud-based architecture and analyzed hundreds of user interactions within difficult video genres (lecture, how-to, documentary) by modeling them as user interest time series. We found that the replaying activity is better than the skipping forward one in matching the semantics of a video, and that all interesting video segments can be found within a factor of two times the average user skipping step from the local maximums of the replay time series. The concept of simple signal processing of implicit user interactions within video could be applied to any type of Web video system (e.g., TV, desktop, tablet), in order to improve the user navigation experience with dynamic and personalized key-frames.
  19. Mikalef, K., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2013. Does informal learning benefit from interactivity? The effect of trial and error on knowledge acquisition during a museum visit. International Journal of Mobile Learning and Organisation 7, 2, 158–175.
    Informal learning settings, such as museums and cultural heritage locations, have employed interactive mobile applications. Educators and museum curators recognise the value of interactivity, but the optimum level of interactivity in informal learning remains unclear. We developed an informal learning activity with quiz questions about art theory, which we integrated in a between–groups experimental design with three groups of high–school students at an art gallery. Each of the three groups received a different treatment: (a) an interactive mobile–based learning activity, (b) a paper–based version of the same learning activity, and (c) a self–guided museum tour. Students who enrolled with the interactive version showed higher performance in the post–assessment test when compared to the paper–based version. Notably, the benefits of the interactive version are attributed to the immediate feedback of the quiz application during the visit. Further research should perform similar controlled experiments in order to assess the learning benefit of more immersive interactive systems, such as three–dimensional graphics and augmented reality.
  20. Koutsourelakis, C. and Chorianopoulos, K. 2010. Icons in mobile phones Comprehensibility differences between older and younger users. Information Design Journal 18, 1, 22–35.
    Mobile phones have become a ubiquitous information and telecommunication terminal used by diverse age groups. Despite research findings that indicate the special needs and skills of senior citizens, contemporary handsets offer limited consideration for them. We investigated whether typical mobile phone icons are suitable for older users, as measured through unaided icon comprehension. For this purpose, we studied 38 users and evaluated 25 icons, which we captured from five different handsets. It was found that there are significant differences in icon comprehension performance between older and younger mobile phone users. We conclude that designers of mobile phone icons have to regard older user groups differently and we describe the qualities of icons suitable to each one of the age groups. Finally, we highlight the need for additional similar research in different ethnic and cultural groups.
  21. Banakou, D. and Chorianopoulos, K. 2010. The effects of Avatars Gender and Appearance on Social Behavior in Online 3D Virtual Worlds. Journal of Virtual Worlds Research 2, 5.
    In this article, we investigate the effects of avatars appearance on user sociability in 3D virtual worlds. In particular, we study gender and appearance differences in social communication preferences and behavior in virtual public spaces. For this purpose, we have employed the virtual ethnographic method, which is an adaptation of traditional ethnography for the study of cyberspace. Although we only employed nine users who used four different avatars, we observed a cumulative of more than two hundreds social encounters. We found that users with more elaborate avatars had a higher success rate in their social encounters, than those users with the default avatars. Most notably, female users selected to speak with male avatars much more frequently, when using the attractive avatar, which indicates a self-confidence effect induced by the appearance of the personal avatar.
  22. Koutsourelakis, C. and Chorianopoulos, K. 2010. Unaided Icon Recognition in Mobile Phones: A Comparative Study with Young Users. The Design Journal 13, 3, 313–328.
    This article investigates whether the diversity of mobile phone icons has a negative effect on user perception, as measured through unaided icon recognition. We designed an experiment involving fifty-two young users and evaluated twenty-five icons from five different mobile phone handsets. It was found that there are significant differences between alternative icons used for the same mobile phone feature. Moreover, we found that original manufacturer icons performed better than those offered by the wireless operator. Simple metaphors from the real world and consistent visual depictions across different handsets performed best for mobile phone icons, while abstract concepts had the lowest recognition rates. Designers of mobile phone icons have to balance a trade-off between the need of the manufacturers and wireless operators to differentiate their offerings through branding, and the need of the consumers for a familiar visual language in mobile phone menus.
  23. Chorianopoulos, K. 2008. User Interface Design Principles for Interactive Television Applications. International Journal of Human-Computer Interaction 24, 6, 556–573.
    Interactive Television (ITV) applications gratify entertainment needs and leisure activities in a relaxed domestic context. Then, the mentality of efficiency and task completion implied by many user interface heuristics may not be suitable for design and expert evaluation of ITV. In line with the contemporary movement towards the design of the user experience of computing systems, a set of design principles for ITV applications has been developed. Instead of information technology, the field of communication science was explored, which has accumulated an extensive theory of TV usage and viewer behavior. For the empirical validation, the principles were employed in the design of an interactive music TV application. The results suggest that a small set of generic principles could support the systematic design of ITV applications and produce a design rationale that is traceable and comparable to alternative solutions, during the process of early product development. In addition, the principles could be refined into specific guidelines and further employed to support expert evaluation techniques.
  24. Chorianopoulos, K. and Spinellis, D. 2007. Coping with TiVo: Opportunities of the networked digital video recorder. Telematics and Informatics 24, 1, 48–58.
    Despite the progressive switch to digital TV, there has not been any significant change to the value chain of the TV industry. At the same time, the introduction of novel information and communication technologies, such as the digital video recorder (DVR) and efficient Peer-to-Peer (P2P) content distribution, have been regarded as a threat to the established broadcast business players. Previous research has described these threats and has suggested competitive strategies, but it has not investigated the opportunities. This work aims to identify a framework of new business models that take advantage of the networked DVR. For this purpose, we examined the TV literature from diverse academic disciplines, such as mass communication, computer engineering and advertising research. We have also collaborated with network and multimedia engineers, with broadcasters, and we examined novel interactive television (ITV) prototypes. The findings suggest that the networked DVR could be exploited to provide personalized channels and that the dynamic advertising insertion could be introduced as an effective advertising format. In the light of these findings, the TV industry should consider the pro-active adoption and facilitation of the networked DVR infrastructure.
  25. Chorianopoulos, K. 2007. Content-Enriched Communication-Supporting the Social Uses of TV. COMMUNICATIONS NETWORK JOURNAL 6, 1, 23–30.
    The technological difference between the broadcast and the telecommunications industries has imposed an artificial distinction between content distribution and interpersonal communication. As a result, content has to be distributed and consumed through broadband, unidirectional and inflexible TV channels, while interpersonal communication takes place over low-bandwidth bidirectional channels. The convergence of platforms offers many opportunities for integrated content and communication services, which we refer to as content-enriched communication.
  26. Chorianopoulos, K. and Spinellis, D. 2006. User interface evaluation of interactive TV: a media studies perspective. Universal Access in the Information Society 5, 2, 209–218.
    A diverse user population employs interactive TV (ITV) applications in a leisure context for entertainment purposes. The traditional user interface (UI) evaluation paradigm involving efficiency and task completion may not be adequate for the assessment of such applications. In this paper, we argue that unless ITV applications are evaluated with consideration for the ordinary TV viewer, they are going to be appropriate only for the computer literate user, thus excluding the TV audience from easy access to information society services. The field of media studies has accumulated an extensive theory of TV and associated methods. We applied the corresponding findings in the domain of ITV to examine how universal access to ITV applications can be obtained. By combining these results with emerging affective quality theories for interactive products, we propose a UI evaluation framework for ITV applications.
  27. Chorianopoulos, K. 2006. Animated Character Likeability Revisited: The Case of Interactive TV. Journal of Usability Studies 1, 4, 171–184.
    Animated characters have been a popular research theme, but the respective desktop applications have not been well-received by end-users. The objective of this study was to evaluate the use of an animated character for presenting information and navigating music videos within an interactive television (ITV) application. Information was displayed over music video clips with two alternative user interfaces: 1) semi-transparent information overlays, 2) an animated character. For this purpose, the differences between ITV and desktop computing motivated the adaptation of the traditional usability evaluation techniques. The evaluation revealed that users reported higher affective quality with the animated character user interface. Although the success of animated characters in desktop productivity applications has been limited, there is growing evidence that animated characters might be viable in a domestic environment for leisure activities, such as interactive TV.
  28. Chorianopoulos, K. and Spinellis, D. 2004. User interface development for interactive television: extending a commercial DTV platform to the virtual channel API. Computers & Graphics 28, 2, 157–166.
    We explore the generation of interactive computer graphics at digital set-top boxes in place of the fixed graphics that were embedded to the television video before the broadcast. This direction raises new requirements for user interface development, since the graphics are merged with video at each set-top box dynamically, without the traditional quality control from the television producers. Besides the technical issues, interactive computer graphics for television should be evaluated by television viewers. We employ an animated character in an interactive music television application that was evaluated by consumers, and was developed using the Virtual Channel Control Library, a custom high-level API, that was built using Microsoft Windows and TV technologies.
  29. Chorianopoulos, K. and Spinellis, D. 2004. Affective usability evaluation for an interactive music television channel. Comput. Entertain. 2, 3, 14–14.
    Computer-mediated television brings new requirements for user interface design and evaluation, since interactive television applications are deployed in a relaxed domestic setting and aim to gratify the need for entertainment. Digital video recorders, the generation of custom computer graphics on each digital set-top box, and the introduction of new advertising formats are important issues for research and practice. We explore the employment of an animated character and the dynamic insertion of advertising in the design of an intuitive user interface for interactive music-video television. We found that the animated character and the skippable videoclip feature seamlessly enhanced consumer satisfaction, as shown by affective usability questionnaires.

Conferences

  1. Merkouris, A. and Chorianopoulos, K. 2017. Programming Human-Robot Interactions in Middle School : The Role of Mobile Input Modalities in Embodied Learning. International Conference on Interactive Mobile Communication, Technologies and Learning (IMCL2017), Springer, 146–153.
    Embodiment within robotics can serve as an innovative approach to attracting students to computer programming. Nevertheless, there is a limited number of empirical studies in authentic classroom environments to support this assumption. In this study, we explored the synergy between embodied learning and educational robotics through a series of programming activities. Thirty-six middle school students were asked to create applications for controlling a robot using diverse interaction modalities, such as touch, speech, hand and full body gestures. We measured students’ preferences, views, and intentions. Further- more, we evaluated students’ interaction modalities selections during a semi- open problem-solving task. The results revealed that students felt more confident about their programming skills after the activities. Moreover, participants chose interfaces that were attractive to them and congruent to the programming tasks.
  2. Leftheriotis, I., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2015. Interaction Space of Chords on a Vertical Multi-touch Screen. Proceedings of the 2015 International Conference on Interactive Tabletops & Surfaces - ITS ’15, ACM Press, 355–360.
    Despite the increasing use of Multi-Touch (MT) capable devices, novel interaction techniques need to be examined in order to swift from a single-touch WIMP interaction paradigm to a MT one.In this work, we focus on chord interaction on vertical MT screens. Chord is the simultaneous touch of more than one finger on the MT screen. Based on a user experiment with 12 users, we explore the positioning - interaction space of the chord technique, by investigating a relation among the type of the chord (number of fingers) and the position on the screen that the chord was applied. The empirical results have indicated an interaction pattern that demonstrates a significant relation between the type of the chord that was applied (number of fingers) and its position on the screen. Our results show that as the number of fingers needed for a chord increases, the nearer from the bottom left of the screen this chord is to be applied. Notably, our results give evidence of the fact that there is a threshold (five-finger-chord) beyond which the above relation is not strong.
  3. Kravvaris, D., Kermanidis, K.L., and Chorianopoulos, K. 2015. Ranking educational videos: The impact of social presence. 2015 IEEE 9th International Conference on Research Challenges in Information Science (RCIS), IEEE, 342–350.
    The information conveyed via the social media, in addition to the content data, also contains social characteristics that come from the social network users. A special interesting data category concerns the data that come from the natural language present in the social media mainly in the form of video. Our study focuses on the speech content of the videos in the form of transcript and the opinion of the social network users that have watched them. The representation of content data is made through a vector space model that uses cosine similarity measure for the relevant ranking of the transcripts. In order for the ranking to be more comprehensive we suggest the addition of a new parameter that of social weight during the procedure, which will reflect the users’ opinion. There is an analytic presentation of the method being suggested; all the possible cases are being examined and the rules that define the new ranking are put forward. Furthermore, we apply this method to video lectures derived from YouTube. The findings of the experiments show that the addition of the social weight parameter reflects the users’ views without changing to great extent the content based ranking of the video lectures. Finally, a user evaluation experiment was carried out and showed that the ranking procedure that includes the social weight parameter is closer to the users’ ranking preferences.
  4. Merkouris, A. and Chorianopoulos, K. 2015. Introducing Computer Programming to Children through Robotic and Wearable Devices. WiPSCE 2015: The 10th Workshop in Primary and Secondary Computing Education, ACM.
    Learning to program in computer code has been considered one of the pillars of contemporary education with benefits that reach well beyond the skills required by the computing industry, into creativity and self-expression. Nevertheless, the execution of computer programs usually takes place on a traditional desktop computer, which has a limited repertoire of input and output interfaces to engage with the user. On the other hand, pedagogy has emphasized that physical representations and tangible interactive objects benefit learning especially for young students. In this work, we explore the benefits of learning to code for ubiquitous computers, such as robots and wearable computers, in comparison to programming for the desktop computer. For this purpose, thirty-six students participated in a within groups study that involved three types of tangibility at the target computer platform: 1) desktop with Scratch, 2) wearable with Arduino LilyPad, and 3) robotic with Lego Mindstorms. Regardless of the target platform, we employed the same desktop visual programming environment (MIT Scratch, Modkit and Enchanting) and we measured emotional engagement and assessed students’ programming skills. We found that students expressed more positive emotions while programming with the robotic rather than the desktop computer. Furthermore, tangible computing platforms didn’t affect dramatically students’ performance in computational thinking.
  5. Giannakos, M.N., Garneli, V., and Chorianopoulos, K. 2015. Exploring the Importance of Making in an Educational Game Design. ICEC 2015, Springer.
    Educational games have been employed in many settings as a means to engage young students. Different genres and applications of games have been used to improve learning experience. The design or making of games in learning activities has been linked to teaching of new skills. Within this paper we explore and discuss the differences of involving young students into the game design and development process compared to just playing an educational game. In particular, we designed an educational math-game and an activity that involves children in playing or modifying the game, and we performed a between groups experiment with sixty students of the second grade of middle school (12 to 13 years old). Students formed three equivalent groups of twenty. The first group played the game, the second engaged with re-designing and modifying the game and the third (control) group solved the same exercises (with the educational game) on paper. The results showed that the making group exhibits certain attitudinal benefits. Hence, our findings suggest that learning through games should include more than just playing a well-designed game, it should also consider the involvement of students with various making affordances.
  6. Garneli, V., Giannakos, M.N., and Chorianopoulos, K. 2015. Computing education in K-12 schools: A review of the literature. 2015 IEEE Global Engineering Education Conference (EDUCON), IEEE, 543–551.
    During the last few years, the focus of computer science education (CSE) in primary and secondary schools (shortly K-12) have reached a significant turning point. This study reviews the published papers on the field of K-12 computing education in order to summarize the findings, guide future studies and give reflections for the major achievements in the area of CSE in K-12 schools. 47 peer-reviewed articles were collected from a systematic literature search and analyzed, based on a categorization of their main elements. Programming tools, educational context, and instructional methods are the main examined categories of this research. Results of this survey show the direction of CSE in schools research during the last years and summarized the benefits as well as the challenges. In particular, we analyzed the selected papers from the perspective of the various instructional methods aiming at introducing and enhancing learning, using several programming tools and educational context in K-12 CSE. Despite the challenges, the findings suggest that implementing computing lessons in K-12 education could be an enjoyable and effective learning experience. In addition, we suggest ways to facilitate deep learning and deal with various implications of the formal and informal education. Encouraging students to create their own projects or solve problems should be a significant part of the learning process.
  7. Chorianopoulos, K., Giannakos, M.N., Chrisochoides, N., and Reed, S. 2014. Open Service for Video Learning Analytics. 2014 IEEE 14th International Conference on Advanced Learning Technologies, IEEE, 28–30.
    Video learning analytics are not open to education stakeholders, such as researchers and teachers, because online video platforms do not share the interactions of the users with their systems. Nevertheless, video learning analytics are necessary to all researchers and teachers that need to understand and improve the effectiveness of the video lecture pedagogy. In this paper, we present an open video learning analytics service, which is freely accessible online. The video learning analytics service (named Social Skip) facilitates the analysis of video learning behavior by capturing learners’ interactions with the video player (e.g., seek/scrub, play, pause). The service empowers any researcher or teacher to create a custom video-based experiment by selecting: 1) a video lecture from You Tube, 2) quiz questions from Google Drive, and 3) custom video player buttons. The open video analytics system has been validated through dozens of user studies, which produced thousands of video interactions. In this study, we present an indicative example, which highlights the usability and usefulness of the system. In addition to interaction frequencies, the system models the captured data as a learner activity time series. Further research should consider user modeling and personalization in order to dynamically respond to the interactivity of students with video lectures.
  8. Chorianopoulos, K., Giannakos, M.N., and Chrisochoides, N. 2014. Design Principles for Serious Games in Mathematics. Proceedings of the 18th Panhellenic Conference on Informatics - PCI ’14, ACM Press, 1–5.
    Although there has been a lot of interest in the employment of video games in education, there are no clear design guidelines. In this work, after surveying previous work in video game design, we highlighted three design principles: 1) engage the students with a story and a hero, 2) employ familiar game mechanics from popular video games, and 3) provide constructive trial and error gameplay for learning. As an illustrating example of those principles, we designed a video game that teaches addition and subtraction of signed numbers. Finally, we outline several more serious games that have adopted the above design principles. The results should be useful for designers, teachers, and researchers who work in the area of serious games for learning. Further research should extend and experimentally validate these principles according to the discipline and the learning style of students.
  9. Giannakos, M.N., Chorianopoulos, K., and Chrisochoides, N. 2014. Collecting and making sense of video learning analytics. 2014 IEEE Frontiers in Education Conference (FIE) Proceedings, IEEE, 1–7.
    Teachers have employed online video as an element of their instructional media portfolio, alongside with books, slides, notes, etc. In comparison to other instructional media, online video affords more opportunities for recording of student navigation on a video lecture. Video analytics might provide insights into student learning performance and inform the improvement of teaching tactics. Nevertheless, those analytics are not accessible to learning stakeholders, such as researchers and educators, mainly because online video platforms do not share broadly the interactions of the users with their systems. As a remedy, we have designed an open-access video analytics system and employed it in a video-assisted course. In this paper, we present a longitudinal study, which provides valuable insights through the lens of the collected video analytics. In particular, we collected and analyzed students’ video navigation, learning performance, and attitudes, and we provide the lessons learned for further development and refinement of video-assisted courses and practices.
  10. Rautiainen, M., Heikkinen, A., Sarvanko, J., Chorianopoulos, K., Kostakos, V., and Ylianttila, M. 2013. Time shifting patterns in browsing and search behavior for catch-up TV on the web. Proceedings of the 11th european conference on Interactive TV and video - EuroITV ’13, ACM Press, 117–120.
    Catch-up TV services on the Web have facilitated time-shifted TV viewing. However, there is limited information about user search behavior with regard to recently time-shifted versus archival TV content. We deployed two distinct content-based web services to explore information retrieval of time-shifted TV content. The first web service is based on a browsing metaphor, while the second is based on free text content search metaphor. We analyzed more than 5000 user sessions from 12 months of logs and found that the programs accessed via browsing categorized program content summaries were typically less than one week old. In contrast, the programs accessed via free text search on subtitle content were typically more than a week old. Our findings provide a first assessment of user behavior in accessing time-shifted and archival TV content. Further research should develop the user experience for content-based TV access and explore the sharing patterns of archival TV content on social networks.
  11. Ilioudi, C., Chorianopoulos, K., and Giannakos, M.N. 2013. Comparing the camera shot styles of video lectures: Close-up versus broad framing of whiteboard and lecturer. 7th International Conference in Open and Distance Learning 2013, 1–7.
    Many educational organizations are motivated to create and share instructional videos, but there are no guidelines about the presentation styles. In practice, the presentation style of video lectures ranges from simple video capturing of classroom teaching, up to highly elaborate authoring of video presentations that include close-ups and video-cuts of instructors, slides, animations, and interactive drawing boards. In particular, there is limited research about the effects of each presentation style on student learning performance and attitudes. In this work, we examine the effects of video presentation styles in supporting the teaching of mathematics in the secondary education. In addition to a control group that studied through a paper-book, two groups of students attended two distinct styles of video lectures: 1) video capture of class teaching (Talking head style), and 2) close-up video capture of an interactive drawing board with voice-over (Khan style). The participants of our study consisted of 36 students (15 boys and 21 girls, 16 years old), who received the respective three treatments (paper book, talking head, khan style), over the course of three math modules in three weeks’ time. We found that learning effects show up only after the second week and that the Talking Head style was more effective than the book for complex topics.
  12. Garneli, V., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2013. Learning by Playing and Learning by Making. 4th International Conference on Serious Games Development and Applications (SGDA 2013), Trondheim, Norway on 25-27 September 2013., 76–85.
    Serious video games have been proposed as a means to engage students with the Science, Technology, Engineering, Mathematics (STEM) curric-ulum, but there is limited research on the required game elements and teaching practices. In particular, there is limited evidence on the effects of the storytelling element and of student involvement in making games on the learning performance and on the attitudes of the students. For this purpose, we designed a between groups experiment with eighty students (12 to 13 years old). They formed three equivalent groups of twenty students each who practiced with a serious game in three different ways. The first group played the storytelling game, the second played the same game but with no story, and the third was engaged with modifying the game code. Finally, the last (control) group practiced traditionally by solving exercises on paper. We found that girls with low grades benefited the most by playing the game and by engaging with the code and that the game making group wishes to repeat the exercise. Further research should perform similar studies with a focus on involving students in serious game modification, over longer periods of time and for additional curriculum topics.
  13. Makris, D., Euaggelopoulos, K., Chorianopoulos, K., and Giannakos, M.N. 2013. Could you help me to change the variables ? Comparing instruction to encouragement for teaching programming. WiPSCE ’13, November 11-13, 2013, Aarhus, Denmark.
    Computer programming has become an important skill and it can be taught from early school years. Previous research has developed and evaluated several visual programming tools that are suitable for computer education in schools. However, little is known about how pedagogic styles affect student attitudes towards learning computer programming. This paper reports on a preliminary study on the influence of alternative teaching styles on student’s enjoyment and attitude towards computing. Two groups of twelve students each were asked to revise a computer game. The traditional instruction group was provided with detailed information, while the encouragement group was asked to help the teacher to change the variables of the game. The results indicate that an encouraging pedagogic style promotes more positive attitudes towards computer programming and more self-confidence than traditional instruction. Further research should repeat the experiment across several weeks for more programming concepts and should also assess the cognitive benefits.
  14. Mikalef, K., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2012. Do Not Touch the Paintings! The Benefits of Interactivity on Learning and Future Visits in a Museum. ICEC 2012, Springer, 553–561.
    Educators and museum curators have recognized the value of interactivity, but it remains unclear what is the right level of interactivity in informal learning settings, such as museums. In this study, we explore the effect of in- creasing levels of interactivity on learning performance and students’ intention for future museum visits. We developed an educational mobile application based on QR codes and quiz software, in order to augment visual arts comprehension during a visit to an art gallery. In addition to the mobile-based version of the game, a paper-based version was also employed followed by a controlled experiment. A total of 60 lyceum students (between 15 and 16 years old) participated in a between-groups evaluation that compared the performance of three levels of interactivity (passive guided tour, paper-based, mobile-based), as well as the perceptions among the groups. The results indicate that the mobile-based student group had higher performance in the post-assessment when compared with the paper-based one. Notably, perceived interest for the game affects students’ perceptions for a future museum visit. Further research should consider the effects of higher-fidelity types of mobile applications, such as 3D graphics, as well as augmented-reality games.
  15. Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2012. Math is not only for Science Geeks : Design and Assessment of a Storytelling Serious Video Game. In Proceedings of the 2012 12th IEEE International Conference on Advanced Learning Technologies, IEEE Computer Society, 418–419.
    Educational video games have been employed by teachers in order to make educational software more attractive to students. However, limited research has been made on the design and assessment of the storytelling elements and the educational effectiveness of these games in sciences curricula. For this purpose, we used Scratch to develop a storytelling mathematics video game and then we measured its educational effect to a small group of twelve students. We found that the story-based math video game has captivated the interest of students and it has been beneficial in the improvement of their performance in an assessment test. Most notably, the improvement was higher for students who used to have poor performance in mathematics. In practice, educators should develop similar games for similar science topics (e.g., physics, chemistry, etc), while further research should consider the active involvement of students in the design of serious games.
  16. Leftheriotis, I., Chorianopoulos, K., and Jaccheri, L. 2012. Tool support for developing scalable multiuser applications on multi-touch screens. Proceedings of the 2012 ACM international conference on Interactive tabletops and surfaces - ITS ’12, ACM Press, 371–374.
    MT (Multi-touch) screens are platforms that enhance multiuser collaboration. In this work, we underline the need for novel interaction techniques and toolkits that allow multi-user collaboration on larger MT surfaces. We present ChordiAction toolkit that makes use of a novel chorded interaction technique allowing simultaneous multi-user interaction on scalable MT applications. We describe the design, the architecture and some efficient customizations practices of the toolkit and show how it can be effectively embedded in an application for multiuser interaction. As a proof of concept, we present some example applications using ChordiAction toolkit showing its potentials and discuss our future plans for further evaluation of this technique.
  17. Kravvaris, D., Thanou, E., and Chorianopoulos, K. 2011. Evaluation of Tip-Activated and Push-Button Infrared Pens for Interactive Whiteboards. Informatics (PCI), 2011 15th Panhellenic Conference on, 287–291.
    Many schools are replacing traditional whiteboards with interactive versions connected to computers and operated with a digital pen. Previous research has established that interactive whiteboards facilitate the learning activities, but there is limited research on the usability of the available digital pens. In particular, the Wiimote project is a cheap interactive whiteboard that employs an infrared pen, which is available in two versions: 1) push button and 2) tip activated. The push button is a pen which functions is similar to that of a mouse and the tip activated is a pen that acts like a "real" pen. In this article, we present an experiment that compares the usability of two infrared pens (push button and tip activated) in a target acquisition and a docking task. In addition to those typical input device tasks, we developed a more realistic drawing task, in order to assess the accuracy of each input device. We found that the tip activated pen is more usable, more accurate, and creates less fatigue.
  18. Du, H., Inkpen, K., Chorianopoulos, K., et al. 2011. VideoPal: Exploring Asynchronous Video-Messaging to Enable Cross-Cultural Friendships. ECSCW 2011: Proceedings of the 12th European Conference on Computer Supported Cooperative Work, 24-28 September 2011, Aarhus Denmark, Springer London, 273–292.
    Pen pal programs for connecting students from around the world through letter writing have been popular for generations. However, traditional technologies have several limitations in supporting pen pal activities. In this study, we explored the potential of video-based asynchronous messaging in supporting the development of children’s cross-cultural friendships. This paper presents the results of a 2-month study of 30 children from the USA and Greece, exploring their uses of, and experiences with, email and an asynchronous video-based messaging tool we developed called VideoPal. The results from this work highlight the important benefits video provides compared to its text counterpart - email. We conclude with a discussion of the key factors that video enables to benefit the development of children’s long-distance friendships.
  19. Giannakos, M.N., Chorianopoulos, K., Johns, P., Inkpen, K., and Du, H. 2011. Childrens Interactions in an Asynchronous Video Mediated Communication Environment. Human-Computer Interaction – INTERACT 2011, Springer Berlin Heidelberg, 199–206.
    Video-mediated communication (VMC) has become a feasible way to connect people in remote places for work and play. Nevertheless, little research has been done with regard to children and VMC. In this paper, we explore the behavior of a group of children, who exchanged video messages in an informal context. In particular, we have analyzed 386 videos over a period of 11 weeks, which were exchanged by 30 students of 4 th and 5 th grade from USA and Greece. We found that the number of views and the duration of a video message significantly depend on the gender of the viewer and creator. Most notably, girls created more messages, but boys viewed their own messages more. Finally, there are video messages with numerous views, which indicates that some videos have content qualities beyond the communication message itself. Overall, the practical implications of these findings indicate that the developers of asynchronous VMC should consider functionalities for preserving some of the video messages.
  20. Chorianopoulos, K., Leftheriotis, I., and Gkonela, C. 2011. SocialSkip: Pragmatic Understanding within Web Video. 9th european conference on European interactive television conference (EuroITV ’11), 25–28.
    In this paper, we present a system that facilitates the analysis of user activity within a web video. Previous research in user-based techniques has assumed an extra effort from the users, such as video replies, comments, tags, and annotations. We have developed and evaluated the SocialSkip system, which improves sense making of web videos by visualizing the simplest form of user interactions with video, such as pause, and seek. In contrast to previous stand-alone implementations, the SocialSkip system employs a web-video player and cloud-based resources (application logic, database, content). The system was validated with two user studies, which provided several hundreds of user interactions with five types of web video (sports, comedy, lecture, documentary, how-to). We found that seeking activity within web video is reversely proportional to how interesting the video is. Moreover, we suggest that if the users are actively seeking for information within a video (e.g., lecture, how-to), then the user activity graph could be associated with the semantics of the video. Finally, SocialSkip provides an open architecture for collaborative contributions to the analysis of the user activity data, in a fashion similar to the TRECVID workshop series.
  21. Leftheriotis, I. and Chorianopoulos, K. 2011. User Experience Quality in Multi-Touch Tasks. 3rd ACM SIGCHI symposium on Engineering interactive computing systems (EICS ’11), 277–282.
    In this paper, we present an updated set of experimental tasks and measures for large multi-touch (MT) input devices. In addition to a multi-user condition, we have employed an updated set of tasks, as well as subjective measures for user enjoyment. In the first experiment (a target acquisition task with two moving targets), the MT was more efficient than the mouse. Surprisingly, we found that the reduced accuracy of MT did not affect the perceived usability, or the enjoyment of the users. In the second experiment (a multiple shapes docking task), the MT was again more efficient and enjoying than the mouse. In the two-user condition, we found that performance and enjoyment was always higher than the single-user conditions, regardless of input device and task. Besides the quantitative results, we observed that users employed diverse interaction strategies in the MT condition, such as bi-manual input. The proposed tasks and the results support the use of MT in entertainment applications (multimedia and video-games), collaborative work, and scientific visualizations with complex data.
  22. Leftheriotis, I. and Chorianopoulos, K. 2011. Multi-user Chorded Toolkit for Multi-touch Screens. 3rd ACM SIGCHI symposium on Engineering interactive computing systems (EICS ’11), 161–164.
    In this work, we present the design and implementation of a chorded menu for multiple users on a large multi-touch vertical display. Instead of selecting an item in a fixed menu by reaching for it, users make a selection by touching multiple fingers simultaneously on any place of the display. Previous research on multi-touch toolkits has provided basic access to touch events, but there is no support for advanced user interface widgets, such as chords. For this purpose, we extended the open-source PyMT toolkit with an architecture that supports alternative user interaction strategies with chorded menus. In addition, we built a multi-user extension that supports chords for two or more users. Chords could be used for having user-aware MT applications. Our toolkit is open source and has been designed as a widget that could be integrated into broader interaction frameworks for multi-touch screens.
  23. Chorianopoulos, K. and Polymeris, G. 2010. A case study of the deployment of cultural probes in remote schools. 7th Pan-Hellenic Conference with International Participation «ICT in Education», University of Peloponnese, Korinthos, Greece, 23-26 September 2010, 185–188.
    Cultural probes have emerged as an effective user requirements capturing toolset for sensitive environments, such as domestic and educational settings. Previous efforts with cultural probes have been done on a small scale with no more than 20 users and have mostly considered urban environments. In contrast, we have collected cultural probes from more than ten remote schools and involved more than 100 students and teachers. We have found that some of the original analog probes might be already outdated in the face of contemporary digital tools and technologies, even in places that have remained greatly unaffected by modern life. The results of this study provide a framework for employing, administering, and analyzing cultural probes in longitudinal studies of remote places.
  24. Giannakos, M.N., Giotopoulos, K.K., and Chorianopoulos, K. 2010. In the face (book) of the daily routine. Proceedings of the 14th International Academic MindTrek Conference on Envisioning Future Media Environments - MindTrek ’10, ACM Press, 153–157.
    This paper investigates the uses of the popular social networking site Facebook, and the perceptions of the users which derive from their Facebook experience. In the exploratory stage, 70 users generated phrases to describe the manner they used Facebook. Interestingly, some users do not only describe the uses, but also mention how they perceive these uses. These phrases were coded into 14 items and then clustered into 4 factors. The second stage of the study, which was addressed to 131 Facebook users, the factor analysis that was conducted, verified the validity of the four factors: Social Connection, Social Network Surfing, Wasting Time, Using Applications. Finally, the results were analyzed in order to interpret each factor’s impact and to enable a comparison with previous research regarding the same subject. These showed how users continue to primarily regard Facebook as a means of socializing with other users, but also the extent to which Facebook has become a part of their daily routine, something that is indicated by the impact of the "Wasting Time" factor. Further research can be conducted by addressing a greater number of users, selected with a less random manner and possibly with a different (cultural, economical etc.) background.
  25. Chorianopoulos, K. and Cesar, P. 2009. Taking Social TV beyond chatting: How the TV viewer adds value to the Network. MCIS 2009., 39.
    In this paper, we provide a comprehensive overview of the state-of-the-art in a contemporary iTV research area: social and networked TV. In our approach, instead of considering research sub-topics that build upon particular disciplinary threads (e.g., usability, personalization, multimedia annotations), we take a multidisciplinary approach that builds upon findings in media studies, human-computer interaction and multimedia systems. Moreover, we downplay the importance of chatting over a distance in favor of non-verbal communication modalities. In contrast, we focus on Social TV practices and highlight the role of each viewer as a node that adds value to the TV network. Finally, we provide directions for further research in neglected topics, such as supporting collocated viewing, and sharing the TV experience in a seamless way.
  26. Banakou, D., Chorianopoulos, K., and Anagnostou, K. 2009. Avatars Appearance and Social Behavior in Online Virtual Worlds. 2009 13th Panhellenic Conference on Informatics, IEEE, 207–211.
    In this article, we investigate the effects of avatars appearance on user social behavior in online virtual worlds. In particular, we study appearance differences in social communication preferences and behavior in virtual public spaces. For this purpose, we have employed virtual ethnographic methods, which is an adaptation of traditional ethnography for the study of cyberspace. We employed nine users who used four different avatars and we observed a cumulative of more than two hundreds social encounters. The results of the study indicate that avatars appearance is an important factor in determining the social communication patterns between users in online 3D worlds. In particular, we found that users with more elaborate avatars had a higher success rate in their social encounters, than those users with the default avatars. The implications of this study raise several issues for the design of avatars, as well as for the study of social communication in online 3D worlds.
  27. Chorianopoulos, K. 2009. Evaluating the social effects of distant education beyond the desktop computer. 5th International Conference on Open and Distance Learning (ICODL), Hellenic Open University Press, 117–121.
    In this article, we explore the methodological aspects for the longitudinal evaluation of a mass communication system that brings together a physically distributed educational community. There is a significant body of related research, but no integrated approach. In particular, previous academic research has not been evaluated with casual users in public spaces for prolonged periods of time. As a matter of fact, the most interesting effects of distance communication systems on everyday life, such as community identity, community awareness, and civic participation have not been documented. For this purpose, we plan to deploy an ambient and social interactive TV platform that supports social communication between remote and isolated schools. Here, we describe tools and techniques for a systematic longitudinal evaluation of the social effects of the media communication system on an educational setting.
  28. Oumard, M., Mirza, D., Kroy, J., and Chorianopoulos, K. 2008. A cultural probes study on video sharing and social communication on the internet. Proceedings of the 3rd international conference on Digital Interactive Media in Entertainment and Arts - DIMEA ’08, ACM Press, 142–148.
    The focus of this article is the link between video sharing and interpersonal communication on the internet. Previous works on social television systems belong to two categories: 1) studies on how collocated groups of viewers socialize while watching TV, and 2) studies on novel Social TV applications (e.g. experimental set-ups) and devices (e.g. ambient displays) that provide technological support for TV sociability over a distance. The main shortcoming of those studies is that they have not considered the dominant contemporary method of Social TV. Early adopters of technology have been watching and sharing video online. We employed cultural probes in order to gain in-depth information about the social aspect of video sharing on the internet. Our sample consisted of six heavy users of internet video, watching an average of at least one hour of internet video a day. In particular, we explored how they are integrating video into their daily social communication practices. We found that internet video is shared and discussed with distant friends. Moreover, the results of the study indicate several opportunities and threats for the development of integrated mass and interpersonal communication applications and services.
  29. Riecke, R., Juers, A., and Chorianopoulos, K. 2008. Interaction Design in Television Voting: A Usability Study on Music TV and Input Devices. Proceedings of the 6th European conference on Changing Television Environments, Springer Berlin Heidelberg, 268–272.
    The aim of this work is to study the usability of voting on music TV channels. We asked subjects to perform a voting-task on two different music TV shows. The results indicate, that 1) there are small differences in acceptance and understanding of the voting-instructions between users and non-users, 2) the mobile phone is a familiar and the most preferred voting-device and 3) sociability features is a way to support the pricing model of voting services for entertainment applications in TV.
  30. Cesar, P. and Chorianopoulos, K. 2008. Interactivity and user participation in the television lifecycle. Proceeding of the 1st international conference on Designing interactive user experiences for TV and video - uxtv ’08, ACM Press, 125–128.
    Interactive TV research encompasses a rather diverse body of work (e.g. multimedia, HCI, CSCW, UIST, user modeling, media studies) that has accumulated over the past 20 years. In this article, we highlight the state-of-the-art and consider two basic issues: What is interactive TV research? Can it help us reinvent the practices of creating, sharing and watching TV? We survey the literature and identify three concepts that have been inherent in interactive TV research: 1) interactive TV as content creation, 2) interactive TV as a content and experience sharing process, and 3) interactive TV as control of audiovisual content. We propose this simple taxonomy (create-share-control) as an evolutionary step over the traditional hierarchical produce-distribute-consume paradigm. Moreover, we highlight the importance of sociability in all phases of the create-share-control model.
  31. Chorianopoulos, K. 2007. Interactive TV design that blends seamlessly with everyday life. Proceedings of the 9th conference on User interfaces for all, Springer-Verlag, 43–57.
    Television use does not require high skill or effort, which is ideal as a paradigm of use for ambient user interfaces. In this paper, universal access in ambient intelligence is modeled after the use of TV in everyday life. Instead of considering television only as a content medium and the focus of user activity, an alternative approach is to consider television use as a secondary function to other activities, such as socializing, domestic chores, leisure pursuits. For this purpose, the requirements for ambient user interactivity with TV are organized in a small set of design principles. The design principles have been selected, analyzed and synthesized from readings in previous works on media and ethnographic studies about television, and everyday life. It is suggested that universal access in ambient intelligence is promoted by considering design principles such as opportunistic interaction, user participation, group interactions, and multiple levels of attention to the user interface. Finally, the principles have been tested in the design of a user interface for interactive music television. This preliminary case suggests that the proposed principles facilitate the design of user interfaces that blend seamlessly with everyday life.
  32. Chorianopoulos, K. 2007. Ambient and social TV: a conceptual design that connects everyday life in a sporadic community. 3rd IET International Conference on Intelligent Environments, 2007. IE 07., 585–588.
    In this research program, we explore the relationship between television use, architectural space, and community identity. In particular, we discuss the conceptual design of a system that brings together the physically distributed academic community (students, academic and administrative staff) of the University of the Aegean. We propose the employment of networked interactive video installations in everyday places (e.g. cafeteria, halls) of the university. In this paper, we explore previous related research and we discuss design issues and approaches for the case of the University of the Aegean.
  33. Chorianopoulos, K. and Rieniets, T. 2007. City of collision: an interactive video installation to inform and engage. IET Conference Publications, 502–509.
    This article describes an interactive video installation that was developed to inform and engage people about one of the most upsetting geopolitical issues of our time: The Israeli-Palestinian conflict. Several layers of maps information have been employed into a computer application, which was programmed with the open source tool Processing. The video installation was chosen as a medium, to achieve the following aims: 1) The visualization and communication of the Israeli-Palestinian conflict, and 2) the application of ambient intelligence technology into artistic works. In this article, we present the requirements, concepts and design decisions for an interactive video installation that has been tested in the lab. Moreover, we provide a reflection on the creative process and the collaboration between different disciplines, such as architecture, urban planning, cartography, computer engineering and media studies. Finally, we outline the plan to evaluate the performance of the system and the impact of the interactive video installation during an exhibition.
  34. Chorianopoulos, K., Lekakos, G., and Spinellis, D. 2003. The Virtual Channel Model for Personalized Television. Proceedings of the 1st European Conference on Interactive TV (EuroITV 2003), 9.
    This research is based on the realization that the desktop computing paradigm is not appropriate for television, because it is adapted to fundamentally different user aspirations and activities. Instead, the virtual channel is proposed as a model that explains the proper design of user access to personalized television programming. The virtual channel is a model that aids the organization and dynamic presentation of television programming from a combination of live broadcasts, prerecorded content and Internet resources at each set-top box. In this paper, we describe two applications that have been used to validate the virtual channel model. We have employed the properties of the virtual channel model into the design of personalized television advertising and interactive music video clip programming. Finally, we describe an ActiveX control that implements a core set of the virtual channels features.
  35. Chorianopoulos, K., Lekakos, G., and Spinellis, D. 2003. Intelligent user interfaces in the living room. Proceedings of the 8th international conference on Intelligent user interfaces - IUI ’03, ACM Press, 230–232.
    The purpose of this paper is to present our experience from the design of a personalized television application, and the implications for the design of interactive television applications in general. Personalized advertising is a gentle introduction to interactive television applications through a push paradigm that is closer to the established patterns of television use. While personalization is a practice widely used on the Internet, applying personalization techniques over digital television infrastructures presents significant obstacles, which we address with explicit design moves
  36. Chorianopoulos, K. and Spinellis, D. 2003. A Metaphor for Personalized Television Programming. UNIVERSAL ACCESS THEORETICAL PERSPECTIVES, PRACTICE, AND EXPERIENCE, Springer-Verlag, 187–194.
    Traditional human-computer interaction settings involve a task-oriented approach where the human interacts with an application to accomplish a particular goal. The emergence of media-rich computer-mediated leisure applications requires a fresh view of the current paradigms and a careful examination of how this change of perspective affects their relevance. This paper proposes a metaphor for accessing personalized television programming and suggests an approach for integrating the metaphor into the design of a television user interface. The proposed metaphor is tested in the design of a personalized advertising service. The results of the empirical research are discussed and the suitability of the metaphor for other television programs is examined.
  37. Livaditi, J., Vassilopoulou, K., Lougos, C., and Chorianopoulos, K. 2003. Needs and gratifications for interactive TV implications for designers. 36th Annual Hawaii International Conference on System Sciences, 2003. Proceedings of the, IEEE, 9 pp.
    This paper uses the well-established ?uses and gratifications? theory in order to understand and categorize viewers? needs in the context of digital TV applications. The results of this analysis unveil that such needs can either be ritualized or instrumental. Furthermore, the uses and gratifications theory was applied in order to formulate a questionnaire to which 68 current users of digital TV responded. The results of this empirical study reveal that applications most suitable for the interactive television environment should aim at the gratification of ritualized needs, such as entertainment and communication. Therefore, applications that appeal to instrumental needs, such as information and transactions should be included as add-ons to entertainment and communication services. Finally, the implications of this analysis for the design of interactive television applications are exploited.
  38. Lekakos, G., Papakyriakopoulos, D., and Chorianopoulos, K. 2001. An integrated approach to interactive and personalized TV advertising. Personalized TV 01.
    Following the case of the Internet, Interactive TV can be expected to revolutionise marketing practices and lead to a paradigm shift in the way advertising is developed, conducted, and analysed. Interactive TV, combines the appeal and mass audience of traditional TV with the interactive features such as those currently available on the Web and offers new possibilities for the viewer, who can directly access relevant information and other services being just one-click away. In this context, personalisation of advertisements refers to the use of technology and viewer information in order to tailor commercials and their respective interactive content to each individual viewer profile. In this paper we deal with the topic of advertising over digital interactive TV and describe a specific approach to the delivery of personalised interactive advertisement content to viewers based on their individual profile, focusing on the necessary architecture, mechanisms and user interface issues which reveal a challenging research domain.
  39. Bozios, T., Lekakos, G., Skoularidou, V., and Chorianopoulos, K. 2001. Advanced Techniques for Personalized Advertising in a Digital TV Environment: The iMEDIA System. eBusiness and eWork Conference, Citeseer, 1025–1031.
    This paper presents the innovative approach of the IST project iMEDIA towards Consumer Clustering and Targeted Advertising in a Digital TV Environment. iMEDIA covers the need of Advertising Companies to identify broad classes of TV viewers who will respond similarly to marketing actions, and thus develop their target advertising techniques. The consumers are equipped with a settop box (STB) with storage facilities and a modem. The definition of consumer profiles and clusters is based on demographics, preferences, and analysis of the consumer interactions with the TV, which are tracked automatically. In order to protect consumers’ identities, consumer data are stored locally on the STB and the classification of a consumer in a specific cluster takes place at the client side. Consumer data from the consumers, who permit it, is periodically transferred to the Server where Data Mining techniques are applied. The extracted consumer behavioral rules associate the clusters with consumer profiles and interaction/navigational data and are sent through the broadcast channel to the consumers’ STBs for the classification of each consumer and the playback of the advertisements that match consumer interests.
  40. Lekakos, G., Chorianopoulos, K., and Spinellis, D. 2001. Information Systems in the Living Room: A Case Study of Personalized Interactive TV Design. ECIS 2001, 319–329.
    The birth of the World Wide Web (WWW) in 1993, particularly its graphical user interface, offered marketers opportunities that were previously unimaginable. The WWW allows advanced marketing activities and more particularly interactive marketing, as the user is actively involved in responding to the vendor’s promotion campaign. Interactive TV, also referred to as iTV, combines the appeal and mass audience of traditional TV with the interactive features such as those currently available on the Web. Although personalisation is a practice used widely on the Internet by many sites, applying personalisation techniques over interactive television presents a number of difficulties. In this paper we focus on the design and testing process of the User Interface (UI) for the Interactive & Personalized Advertisement TV viewer. We argue that there are a lot of challenges involved in the designing of interactive TV applications. These are related with the differences of the medium from the traditional PC based Information Systems in terms of input and output devices, viewing environment, number of users and low level of expertise in PC usage.

Workshops and posters

  1. Chorianopoulos, K. 2018. Immortality and resurrection of the digital self. Proceedings of the Digital Culture & AudioVisual Challenges (DCAC) Interdisciplinary Creativity in Arts and Technology, Ionian University, 4.
  2. Hagen, K., Chorianopoulos, K., Wang, A.I., Jaccheri, M.L., and Weie, S. 2016. Gameplay as Exercise Designing an Engaging Multiplayer Biking Exergame. CHI 2016 Adjunct Proceedings.
    We designed and evaluated an exertion video game in order to overcome two challenges that are preventing exergames from becoming a viable sustained exercise alternative; insufficient physical exertion and player retention. This was achieved by implementing common features shared by the most popular video games and seamlessly merging them with the exertion found in exergames. A user study was performed where the exergame was played 132 times over three days by 8 participants. Compared to the control condition, a moderately paced walk, the exergame scored better on both subjective enjoyment and degree of physical activity. Further research could consider alternative versions of exergames, as well as different user groups.
  3. Takoulidou, E. and Chorianopoulos, K. 2015. Crowdsourcing experiments with a video analytics system. IISA.
    The need for more experimental data, but also quicker and cheaper, lead us beyond traditional lab experiments, approaching a new subject pool via a crowdsourcing platform. SocialSkip is an open system that leverages the video clickstream data for extracting useful information about the video content and the viewers. The difficulty of embedding a pre-existing system as a task demands a carefully designed interface, adjusting experiments and be aware of workers’ cheating behavior. We present a replicable task design and by analyzing crowdsourced results, we highlight problems in experimental procedure and propose potential solutions for future crowdsourcing experiments. The proposed crowdsourcing methodology achieved the collection of a significant amount of video clickstream data, in a timely manner and with affordable cost. Our findings indicate that future social media analytics systems should include an integrated crowdsourcing module. Further research should focus on collecting more data by controlling the random worker behavior a priori.
  4. Chorianopoulos, K. and Pardalis, K. 2015. Mapito.org: Open Geographic Platform for Locative Media Apps. Hybrid City.
    Digital geographical maps have become an important part of many websites and mobile applications. For example, we can embed a map and geo-location tracking into a web page, or into a smartphone application. Nevertheless, the management of user maps and routes is different between the many competing geographic information services. We designed and implemented an open-source and linked-data web service for facilitating the process of a map and route management. The implementation of our open-source web application has been built on-top of existing web services that provide maps. In this way, the Mapito.org service provides an open abstraction layer above the proprietary implementations of commercial companies. Notably, the Mapito platform provides an Application Programming Interface (API), which facilitates the creation and editing of a map and the ability to download the data, or routes without visiting the Web-based user interface. In this paper, we outline the system and provide representative case studies.
  5. Hagen, K., Weie, S., Chorianopoulos, K., Wang, A.I., and Jaccheri, L. 2015. Pedal Tanks A Multiplayer Exergame Based on Teamwork and Competition. ICEC 2015, Springer.
    This installation presents a multiplayer stationary bicycle exergame for four players. The game is played in teams of two, where the players compete to outmaneuver the opposition. Pedal Tanks is being developed to increase the physical activity levels of people struggling to find motivation to exercise. Inspiration for the gameplay has been found in the computer game industry, using elements from contemporary popular computer games and combining them in a cohesive way yields an exergame that is both familiar and engaging. Both the software and hardware used has been custom-made to create an immersive experience where the user forgets that he/she is exercising while playing.
  6. Leftheriotis, I., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2015. Investigating the Potential of a Two-finger Chord Button in Multi-touch Applications. Proceedings of the 2015 International Conference on Interactive Tabletops & Surfaces - ITS ’15, ACM Press, 337–342.
    With the increasing use of multi-touch (MT) capable devices, MT interaction has become a commodity during the last years. From personal devices to larger multi-user screens, MT functionality is nowadays considered as a standard way of performing rich interactions. However, moving from a single-touch interaction to a dual-touch and consequently to MT is not always without challenges for the average user. Although, the use of single-touch is very common, interaction design have yet to be examined thoroughly by taking into account potential differences of single and multi-touch functionality. In this work, we investigate the potential of a two-finger chord button in comparison to the traditional single touch buttons that we find in touchscreens. Based on the fact that users are familiar with single touch buttons (even before the MT screens) our hypotheses are: the use of a two finger chord button a) decreases users’ efficiency, and b) delays users’ responses. In order to investigate our hypotheses, we conducted a controlled experiment with 12 users working on an appropriately designed MT application. The empirical results have indicated that the use of two-finger button significantly delays users’ response-time while it does not affect users’ efficiency on the performed task.
  7. Garneli, V., Giannakos, M.N., Chorianopoulos, K., and Jaccheri, L. 2015. Serious Game Development as a Creative Learning Experience: Lessons Learnt. 2015 IEEE/ACM 4th International Workshop on Games and Software Engineering, IEEE, 36–42.
    Computer programming skills in younger ages seem to be a promising and challenging aspect. Many visual programming tools have been developed in order to assist young students and to improve the current teaching practices and pedagogies. In this paper, we explore the potential effects of a Project Based Learning (PjBL) approach in the field of computer programming. In particular, we try to identify potential differences on students’ programming habits/styles, between game development, simulation, and traditional learning strategy, in the context of PjBL. Our sample consisted of 53 middle school students who formed three groups. Introducing programming through a serious game development approach might inspire students towards a creative learning experience. Moreover, parameters like the class formation might affect the development of programming skills. The students in the PjBL treatment were able to complete a project successfully making fewer mistakes. On the other hand, students enrolled in a more traditional top-down approach chose to experiment with more complex curriculum but not always successfully.
  8. Chorianopoulos, K., Giannakos, M.N., and Chrisochoides, N. 2014. Open system for video learning analytics. Proceedings of the first ACM conference on Learning @ scale conference - L@S ’14, ACM Press, 153–154.
    Video lectures are nowadays widely used by growing numbers of learners all over the world. Nevertheless, learners’ interactions with the videos are not readily available, because online video platforms do not share them. In this paper, we present an open-source video learning analytics system, which is also available as a free service to researchers. Our system facilitates the analysis of video learning behavior by capturing learners’ interactions with the video player (e.g, seek/scrub, play, pause). In an empirical user study, we captured hundreds of user interactions with the video player by analyzing the interactions as a learner activity time series. We found that learners employed the replaying activity to retrieve the video segments that contained the answers to the survey questions. The above findings indicate the potential of video analytics to represent learner behavior. Further research, should be able to elaborate on learner behavior by collecting large-scale data. In this way, the producers of online video pedagogy will be able to understand the use of this emerging medium and proceed with the appropriate amendments to the current video-based learning systems and practices.
  9. Talvis, K., Chorianopoulos, K., and Kermanidis, K.L. 2014. Real-Time Monitoring of Flu Epidemics through Linguistic and Statistical Analysis of Twitter Messages. 9th International Workshop on Semantic and Social Media Adaptation and Personalization, IEEE, 83–87.
    The recent rise in popularity of Twitter and its open API provides developers the opportunity to extract amounts of data which can be a thesaurus of information. This opportunity led to the development of an open source and open API system called Flu track (http://flutrack.org) that monitors influenza epidemics, based on geo-located self-reports on Twitter. In particular, we detect words such as sore throat, cough, fever etc. Moreover, we detect the aggravation of a patient’s clinical condition when a user posts a second flu related tweet that contains words indicating further symptoms such as: worse, deteriorating. Finally, we present flu-positives with real time anonymous visualizations using maps (mapping), which might be helpful for authorities and sensitive populations to plan upcoming events or activities. In order to further aid the surveillance of the spreading of the disease, a classification experiment has been conducted for automatically identifying Tweets that describe cases with acute and more critical symptoms from those referring to milder cases. We found that making use of mereley very small n-gram keyword lexica, the automatic identification of critical cases reaches an accuracy of 92%.
  10. Chorianopoulos, K. and Giannakos, M.N. 2013. Merging learner performance with browsing behavior in video lectures. WAVe 2013 The Workshop on Analytics on Video-based Learning, 38–42.
    Video lectures are nowadays widely used by growing numbers of learners all over the world. Nevertheless, learners’ interactions with the videos are not readily available, because online video platforms do not share them. In this paper, we present an open-source video learning analytics system. The system captures learners’ interactions with the video player (e.g, pause, replay, forward) and at the same time it collects information about their performance (e.g., cognitive tests) and/or attitudes (e.g., surveys). We have already validated the system and we are working on learner modeling and personalization through large scale data analysis. The tool is a freely available open source project for anyone to try and to improve.
  11. Armeni, I. and Chorianopoulos, K. 2013. Pedestrian navigation and shortest path: Preference versus distance. Workshop Proceedings of the 9th International Conference on Intelligent Environments IE’13, July 16-19, 2013, Athens, Greece, IOS, 647–652.
    Contemporary digital maps provide an option for pedestrian navigation, but they do not account for subjective preferences in the calculation of the shortest path, which is usually provided in terms of absolute distance. For this purpose, we performed a controlled experiment with local pedestrians, who were asked to navigate from point A to point B in a fast manner. The pedestrians’ routes were recorded by means of a GPS device and then plotted on a map for comparison with suggested itinerary from a digital map. We found that the preferred shortest path is significantly different to the suggested one. Notably, the preffered paths were slightly longer than the suggested, but there was no effect in the trip duration because there were fewer obstacles, such as cars. Since many pedestrians employ GPS enabled devices, the findings of this research inform the development of mobile applications and the design of new subjective map layers for city dwellers.
  12. Giannakos, M.N., Chorianopoulos, K., Ronchetti, M., Szegedi, P., and Teasley, S. 2013. Analytics on video-based learning. LAK ’13 Proceedings of the Third International Conference on Learning Analytics and Knowledge, ACM, 283–284.
    The International Workshop on Analytics on Video-based Learning (WAVe2013) aims to connect research efforts on Video-based Learning with Learning Analytics to create visionary ideas and foster synergies between the two fields. The main objective of WAVe is to build a research community around the topical area of Analytics on video-based learning. In particular, WAVe aims to develop a critical discussion about the next generation of analytics employed on video learning tools, the form of these analytics and the way they can be analyzed in order to help us to better understand and improve the value of video-based learning. WAVe is based on the rationale that combining and analyzing learners’ interactions with other available data obtained from learners, new avenues for research on video-based learning have emerged.
  13. Giannakis, K., Chorianopoulos, K., and Jaccheri, L. 2013. User Requirements for Gamifying Sports Software. 3rd International Workshop on Games and Software Engineering: Engineering Computer Games to Enable Positive, Progressive Change (GAS), IEEE, 22–26.
    Sports tracking software for casual exercising has become popular with smart phone users who are concerned about their health and fitness. Nevertheless, there is limited research on the user requirements for sports tracking software, which needs to be fun and easy to use in order to appeal to a broad set of users. For this purpose, we employed a four-week long experiment with five users who were asked to perform multiple workouts with two levels of gamification. The first treatment stands for no gamification and the second treatment provided rich visual feedback, such as speed, distance, elapsed time, map. At the end of the experiment, we asked users to describe the devices. Both devices included GPS sensor, so we also measured the distance covered for each one of the workouts. We found that augmented feedback from mobile self-tracking devices can promote working out, but there is also a trade-off of increased anxiety and disorientation. Thus, we suggest that sports tracking software should be modest about how much and what type of visual information it provides to the user. In particular, we found that the only piece of visual information that had an impact on performance was average speed, which indicates a connection with gamication. Further research should consider additional levels of gamification beyond score, such as graphics, sociability, rules.
  14. Ilioudi, C., Giannakos, M.N., and Chorianopoulos, K. 2013. Investigating Differences among the Commonly Used Video Lecture Styles. WAVe 2013 The Workshop on Analytics on Video-based Learning, 21–26.
    Many educational organizations are motivated to create and share instructional videos, but there are no guidelines about the presentation styles. In practice, the presentation style of video lectures ranges from simple video capturing of classroom teaching, up to highly elaborate authoring of video presentations that include close-ups and video-cuts of instructors, slides, animations, and interactive drawing boards. In particular, there is limited research about the effects of each presentation style on student learning performance and attitudes. In this work, we examine the effects of video presentation styles in supporting the teaching of mathematics in the secondary education. In addition to a control group that studied through a paper-book, two groups of students attended two distinct styles of video lectures: 1) video capture of class teaching (Talking head style), and 2) close-up video capture of an interactive drawing board with voice-over (Khan style). The participants of our study consisted of 36 students (15 boys and 21 girls, 16 years old), who received the respective three treatments (paper book, talking head, khan style), over the course of three math modules in three weeks’ time. We found that learning effects show up only after the second week and that the Talking Head style was more effective than the book for complex topics.
  15. Aasbakken, M., Chorianopoulos, K., and Jaccheri, L. 2012. Evaluation of User Engagement and Message Comprehension in a Pervasive Software Installation. 2nd International Workshop on Games and Software Engineering Realizing User Engagement with Game Engineering Techniques , ICSE 2012 workshop, IEEE, 27–30.
    The goal of this work is to explore the relationship between pervasive software and user engagement towards environmental issues. We study this relationship in the context of an art installation that concerns the water cycle in nature. The research question is: How can we design and evaluate software that becomes a medium to engage and inform the user? We have gathered empirical data during a two days exhibition of two versions of a pervasive art installation by: observations, questionnaires, and input logs. Data analysis reveals that the art installation engaged users, with focus on young children, and communicated the intended message. The results are organized according to five important factors for developing and evaluating interacting art installations. These are: 1) data collection method; 2) user interaction; 3) social interaction; 4) issues about children; 5) message comprehension. We suggest that these factors can inform engineering practices for engaging software like video-games.
  16. Avlonitis, M., Chorianopoulos, K., and Shamma, D.A. 2012. Crowdsourcing user interactions within web video through pulse modeling. Proceedings of the ACM multimedia 2012 workshop on Crowdsourcing for multimedia - CrowdMM ’12, ACM Press, 19.
    Semantic video research has employed crowdsourcing techniques on social web video data sets such as comments, tags, and annotations, but these data sets require an extra effort on behalf of the user. We propose a pulse modeling method, which analyzes implicit user interactions within web video, such as rewind. In particular, we have modeled the user information seeking behavior as a time series and the semantic regions as a discrete pulse of fixed width. We constructed these pulses from user interactions with a documentary video that has a very rich visual style with too many cuts and camera angles/frames for the same scene. Next, we calculated the correlation coefficient between dynamically detected user pulses at the local maximums and the reference pulse. We have found when people are actively seeking for information in a video, their activity (these pulses) significantly matches the semantics of the video. This proposed pulse analysis method complements previous work in content-based information retrieval and provides an additional user-based dimension for modeling the semantics of a web video.
  17. Giannakos, M.N., Chorianopoulos, K., Jaccheri, L., and Chrisochoides, N. 2012. This Game Is Girly! Perceived Enjoyment and Student Acceptance of Edutainment. Edutainment 2012, Springer, 89–98.
    Serious video games that enable students to engage into topics as mathematics through an enjoyment process are becoming increasingly popular. However, there is lack of empirical evidence on the relationship between students’ enjoyment and their intention to use serious video games. This study is about a storytelling serious video game, which has the goal to improve the mathematical skills of players. The game has a plot, featuring a story in which a mission is assigned to the player. The story and the mission are used to stimulate the students’ interest and motivate them to play the game. The empirical study is a controlled experiment to which 46 Gymnasium (middle school) students participated. Results confirmed the positive effects of the enjoyment on students’ intention to use storytelling serious games. Notably, we found that gender has a moderating effect on the relationships between enjoyment and intention to use the game. The results of this study suggest that games with a storytelling component might be attractive to girls.
  18. Du, H., Inkpen, K., Tang, J., et al. 2011. VideoPal : An Asynchronous Video Based Communication System to Connect Children from US and Greece. Adjunct Proceedings of CSCW 2011.
    In this paper we describe VideoPal, a novel video based asynchronous communication system. VideoPal is currently being used by approximately 30 4th and 5th grade students from the US and Greece to explore the opportunities and challenges of video-mediated asynchronous communication in supporting traditional Pen Pal activities.
  19. Du, H., Inkpen, K., Tang, J., et al. 2011. VideoPal : System Description. Adjunct Proceedings of CSCW 2011, 1–2.
    In this paper we provide a description of VideoPal, an asynchronous video-mediated communication tool.
  20. Chorianopoulos, K., Fernández, F.J.B., Salcines, E.G., and de Castro Lozano, C. 2010. Delegating the visual interface between a tablet and a TV. Proceedings of the International Conference on Advanced Visual Interfaces - AVI ’10, ACM Press, 418.
    The introduction and wide adoption of small and powerful mobile computers, such as smart phones and tablets, has raised the opportunity of employing them into multi-device scenarios and blending the distinction between input and output devices. In particular, the partnership between a personal device and a shared one provides two possible output screens. Then, one significant research issue is to balance the visual interface between two devices with advanced output abilities. Do the devices compete or cooperate for the attention and the benefit of the user? Most notably, how multi-device interaction is appreciated in multi-user scenarios? Previous research has raised and considered the above research issues and questions for dual screen set-ups in the work environment. In our research, we are exploring multi-device user interface configurations in the context of a leisure environment and for entertainment applications. Our objective is to provide interaction possibilities that are more than the sum of the parts.
  21. Chorianopoulos, K. and Tsaknaki, V. 2010. CELL: Connecting Everyday Life in an archipeLago. workshop Mind the Gap — Towards Seamless Remote Social Interaction (10th Advanced Visual Interafaces conference AVI 2010).
    In this paper, we explore the design of a seamless broadcast communication system that brings together the distributed community of remote secondary education schools. In contrast to higher education, primary and secondary education establishments should remain distributed, in order to maintain a balance of urban and rural life in the developing and the developed world. We plan to deploy an ambient and social interactive TV platform (physical installation, authoring tools, interactive content) that supports social communication in a positive way. In particular, we present the physical design and the conceptual model of the system.
  22. Spiridonidou, A., Kampi, I., and Chorianopoulos, K. 2010. Exploring everyday life in remote schools: A large-scale study with cultural probes and affinity diagrams. workshop on Digital Technologies and Marginalized Youth, IDC 2010.
    In this paper, we describe the process of gathering data from remote schools. We employed cultural probes and analyzed the collected data with the use of the affinity diagrams. This study includes data gathered from more than ten remote schools and involved more than a hundred students and teachers in the process. This is a novelty as previous cultural probes studies have been done on a small scale and have mostly considered urban environments. We found that ICT technologies might not be employed as planned in remote places and that affinity diagrams are more suitable for analyzing unstructured data (e.g., photos, diaries) rather than semi-structured questionnaires. The results of this research provide insights for analyzing cultural probes from remote places.
  23. Willis, K.S., Chorianopoulos, K., Struppek, M., and Roussos, G. 2007. Shared encounters workshop. CHI ’07 extended abstracts on Human factors in computing systems - CHI ’07, ACM Press, 2881–2884.
    Our everyday lives are characterised by encounters, some are fleeting and ephemeral and others are more enduring and meaningful exchanges. Shared encounters are the glue of social networks and have a socializing effect in terms of mutual understanding, empathy, respect and thus tolerance towards others. The quality and characteristics of such encounters are affected by the setting, or situation in which they occur. In a world shaped by communication technologies, non-place-based networks often coexist alongside to the traditional local face-to-face social networks. As these multiple and distinct on and off-line communities tend to carry out their activities in more and more distinct and sophisticated spaces, a lack of coherency and fragmentation emerges in the sense of a shared space of community. Open public space with its streets, parks and squares plays an important role in providing space for shared encounters among and between these coexisting networks. Mobile and ubiquitous technologies enable social encounters located in public space, albeit not confined to fixed settings, whilst also offering sharing of experiences from non-place based networks. We will look at how to create or support the conditions for meaningful and persisting shared encounters. In particular we propose to explore how technologies can be appropriated for shared interactions that can occur spontaneously and playfully and in doing so re-inhabit and connect place-based social networks.
  24. Teran, M., Chorianopoulos, K., Willis, K.S., and Colini, L. 2006. Dousing for Dummies : methods for raising public awareness of ambient communications. Adjunct Proceedings of British Human Computer Interaction conference 2006, 11-15 September 2006, London., 1–3.
    In this paper, we present a series of methods developed by the artist, Michelle Teran, for raising awareness ofinvisible spaces created by public wireless communication technologies. These methods include public performance, w here participation is through a series of walks through the city, and workshops where participants engage in the design implications through a process oflocating, examining and documenting some ofthese invisible networks. Overall, we explore methods and strategies for engaging the public, how to create awareness ofthe limitations oftheir perception of communications technologies and techniques that facilitate the debate on the opportunities that these invisible yet rich in meaning invisible spaces might raise.
  25. Chorianopoulos, K., Barria, J., Regner, T., and Pitt, J. 2005. Cross Media Digital Rights Management for Online Music Stores. First International Conference on Automated Production of Cross Media Content for Multi-Channel Distribution (AXMEDIS’05), IEEE, 257–260.
    Digital music consumers have to choose between illegal file swapping services and online music stores. The latter impose various restrictions to the established music consumption behaviour, such as limitations on the number of devices and proprietary music formats. We describe a business model that is based on a liberal management of music rights, instead of the dominant restrictions of access. The proposed business model facilitates the free flow of music content between different client devices (PC, mobile phone, portable player) and between heterogeneous networks (Web, P2P, wireless, broadcast), but it controls the flow of rights for added value music bundles. The business model is presented over two stages of the customer activity cycle and along the revenue, process and technology elements.
  26. Chorianopoulos, K. and Spinellis, D. 2003. Usability design for the home media station. Proceedings of the 10th HCI International Conference, 439–443.
    Abstract A different usability design approach is needed for the emerging class of home infotainment appliances, collectively referred to as the home media station (HMS). Mass- media theory, consumer electronics engineering, content creation and content distribution ... \backslashn
  27. Chorianopoulos, K. 2003. The digital set-top box as a virtual channel provider. CHI ’03 extended abstracts on Human factors in computing systems (CHI ’03), ACM Press, 666–667.
    This research is based on the realization that the desktop computing paradigm is not appropriate for television, because it is adapted to fundamentally different user aspirations and activities. Instead, the virtual channel is a model that aids the organization and dynamic presentation of digital television programming from a combination of live broadcasts, prerecorded content and Internet resources at each set-top box. The goal is to design the respective framework of user interface patterns that consider the affective nature of television usability and facilitate the diversity of viewing situations.

Tutorials and keynotes

  1. Chorianopoulos, K. and Giannakos, M.N. 2013. Usability design for video lectures. Proceedings of the 11th european conference on Interactive TV and video - EuroITV ’13, ACM Press, 163–164.
    There is a growing number and variety of educational video lectures online, but there is limited understanding of their effectiveness in terms of learning and usability. Although there is significant research literature within the individual domains of usability and of video learning, there is limited understanding of their integrated design. In particular, there is limited research on guidelines for usable video lecture design, such as the presence of humans in the video and navigation support through the video. For example, it is established that learners benefit from highly structured learning material, but the manual editing of video is not feasible for most learning organizations and instructors. In order to accommodate this emerging instruction medium we are drawing design principles and models from the research literature on educational technology and video interaction. Moreover, we provide a comprehensive approach to the design of usable video lecture systems and content. Finally, we suggest that learning organizations and instructors should invest additional effort in video systems that support an integrated approach to editing, sharing, and controlling of video lectures.
  2. Chorianopoulos, K. 2012. Crowdsourcing user interactions with the video player. Proceedings of the 18th Brazilian symposium on Multimedia and the web - WebMedia ’12, ACM Press, 13.
    Every second millions of users enjoy content streaming on diverse video players (e.g., Web, Apps, social networks) and create billions of interactions within online video, such as play, pause, seek/scrub. This collective intelligence of video viewers might be leveraged into useful information for improved video navigation. For example, we can accurately detect and retrieve interesting scenes through the analysis of the aggregated users’ replay interactions with the video player. Effective crowdsourcing of video interactions is grounded on previous work in multimedia, user modeling, and controlled user experiments. These research issues are described for the case of user-based detection of video thumbnails that stand for the semantics of the video. Moreover, we demonstrate the respective experimental environment with a focus on educational and user generated (e.g., how-to, lecture) videos.
  3. Chorianopoulos, K., Jaccheri, L., and Nossum, A.S. 2012. Creative and open software engineering practices and tools in maker community projects. Proceedings of the 4th ACM SIGCHI symposium on Engineering interactive computing systems - EICS ’12, ACM Press, 333–334.
    Processing, Arduino, and the growth of the associated communities of practice, also called maker communities, has motivated a broader participation of non-technical users in the engineering of interactive systems. Besides online sharing, maker communities meet regularly and share knowledge for various purposes (e.g., creative hacking, social networking, lifelong learning). In the context of maker communities, the understanding of engineering interactive systems (e.g., motivations, objectives, collaboration, process, reports) and the design of the respective tools (e.g., end-user programming for artists, or children) are not well documented. As a remedy, we present a coherent overview of related work, as well as our own experiences in the organization and running of maker workshops. The tutorial format (lecture and hands-on workshop) benefits both practitioners and researchers with an understanding of creative software tools and practices. Moreover, participants become familiar with the organization of maker workshops as 1) a research method for understanding users, 2) an engineering process for interactive computer systems, and 3) a practice for teaching and learning.
  4. Cesar, P. and Chorianopoulos, K. 2006. Interactive digital television and multimedia systems. Proceedings of the 14th annual ACM international conference on Multimedia - MULTIMEDIA ’06, ACM Press, 7.
    Interactive digital television is an emerging field with a high impact in our societies: it offers interactive services to the masses. This tutorial aims to establish a common framework by summarizing the most significant results in this multidisciplinary field. The review includes topics such as content distribution, system software of the receivers, and user interaction. In addition, we will discuss current commercial events such as the next generation of optical discs (e.g., blue-ray), BBC peer-to-peer service, and mobile television. Based on this discussion, we will formulate an agenda for further research. The agenda includes, for example, end-user enrichment of television content and social television. This half-day tutorial will provide the attendee a solid understanding of the technologies currently in use and an introduction of the open questions in the field.

Book chapters

  1. Chorianopoulos, K., Shamma, D.A., and Kennedy, L. 2013. Social Video Retrieval: Research Methods in Controlling, Sharing, and Editing of Web Video. In: N. Ramzan, R. van Zwol, J.-S. Lee, K. Clüver and X.-S. Hua, eds., Social Media Retrieval. Springer, 3–22.
    Content-based video retrieval has been a very efficient technique with new video content, but it has not regarded the increasingly dynamic interactions between users and content. We present a comprehensive survey on user-based techniques and instrumentation for social video retrieval researchers. Community-based approaches suggest there is much to learn about an unstructured video just by analyzing the dynamics of how it is being used. In particular, we explore three pillars of online user activity with video content: 1) Seeking patterns within a video is linked to interesting video segments, 2) Sharing patterns between users indicate that there is a correlation between social activity and popularity of a video, and 3) Editing of live events is automated through the synchronization of audio across multiple viewpoints of the same event. Moreover, we present three complementary research methods in social video retrieval: Experimental replication of user activity data and signal analysis, data mining and prediction on natural user activity data, and hybrid techniques that combine robust content-based approaches with crowd sourcing of user gener- ated content. Finally, we suggest further research directions in the combination of richer user- and content-modeling, because it provides an attractive solution to the personalization, navigation, and social consumption of videos.
  2. Chorianopoulos, K. and Rieniets, T. 2010. Shared-Screen Interaction: Engaging Groups in Map-Mediated Nonverbal Communication. In: Shared Encounters. Springer, 81–98.
    This chapter describes the design and development of an interactive video installation that allows participants to explore a map narrative, and engage in group interactions through a shared screen. For this purpose, several layers of cartographic information were employed in a computer application, which was programmed with motion-tracking libraries in the open source tool processing. The interactive video installation has been chosen as a medium to achieve the following aims: (1) The visualization of urban-conflict as an interactive map narrative, and (2) the encouragement of social encounters through a shared screen. The development process begins with the design of interaction between the system and the participants, as well as between the participants themselves. Then we map the interaction design concepts into multimedia and architectural design. Finally, we provide a discussion on the creative process and the collaboration between different disciplines, such as architecture, urban planning, cartography, computer engineering, and media studies.
  3. Willis, K.S., Roussos, G., Chorianopoulos, K., and Struppek, M. 2010. Shared Encounters. In: K.S. Willis, G. Roussos, K. Chorianopoulos and M. Struppek, eds., Shared Encounters. Springer London, London, 1–15.
    The approach often adopted by Human Computer Interaction (HCI) focuses on exchanges between a person and the interface of a device situated within a specific context of use. This view is increasingly challenged by the complex and dynamic world of the physical and social environment integrated with ubiquitous technologies, which requires an alternative view that sees people creating settings which frame and structure their encounters. As a result, in recent years, HCI researchers have recognized the need for social and physical data to be gathered and interpreted, but have often been frustrated in their attempts to codify and make sense of the complex and dynamic nature of the real world of human experience. Developments in the early 90s such as the emergence of the field of Computer Supported Cooperative Work (CSCW), the introduction of the concept of social navigation (Hook et al. 2003), work on ambient environments, the UbiComp conference series as well as more theoretical positions on embodied or situated interaction (Dourish 2001, McCullough 2005) have all lead the way to a new understanding of HCI. Another driver for this change in emphasis in HCI is the emergence of mobile and ubiquitous computing that has brought significant changes in social and cultural practices in spatial settings. Interactions through and with ubiquitous technologies no longer require physical co-presence and have broadened the range of possible interactions as well as the range of settings in which these interactions can unfold. The basis for this lies in the fact that physical distance no longer prevents many of the types of interactions and encounters that had previously been confined to face-to-face contact. As a result, there has been much discussion on the role of spatial setting and interaction mediated through technologies such as that on the role of space and agency in the quality of the interaction (Dourish and Harrisson 1996) and also the broader concept of the situated behavior and actions (Suchman 1987). A good deal has also been written on the subject of social collaboration among individuals using communication devices and the conditions or features that are required to enable such activities (Gaver 1992; Paulos and Goodman 2004; Hook et al. 2003; Churchill et al. 2004). Further discussion has focused on the technologies themselves, assessing the social impact of the emerging forms of behavior, such as the activities of ad hoc communities enabled through mobile technologies (Rheingold 2002), or the patterns of mobile phones’ use (Katz and Aakhus 2002). Finally, numerous applications and locative media projects (e.g., Harle and Hopper 2005) which explore interactions through realization have been developed. These projects and research offer many useful insights, but there still remain many questions about how to create the conditions for meaningful and persisting shared interactions in public space. The challenge is not only to build systems that respond to rich and dynamic social and physical events, but also to provide a structure for sustainable participation and sharing.
  4. Chorianopoulos, K. 2010. Scenarios of Use for Sociable Mobile TV. In: A. Marcus, A.C. Roibás and R. Sala, eds., Mobile TV: Customizing Content and Experience. Springer London, London, 243–254.
    Mobile TVs have been available for many years, without ever becoming very popular. Moreover, the first wave of research has been mostly concerned with technology and standards, which are necessary to ensure interoperability and market acceptance. Although, there has been a significant body of computer-supported co-operative work (CSCW) and mobile human–computer interaction (HCI) research findings, there is limited investigation in the context of leisure activities, such as TV. In this article, we propose three concepts that drive the main paths for research and practice in mobile and social TV: (1) Mobile TV as a content format, (2) Mobile TV as user behavior, and (3) Mobile TV as interaction terminal. Finally, we provide particular directions to be considered in further research in social and mobile TV.
  5. Lekakos, G. and Chorianopoulos, K. 2009. Personalized Advertising Methods in Digital Interactive Television. In: M. Pagani, ed., Encyclopedia of Multimedia Technology and Neworking. IGI Press, 1142–1147.
    The ability to deliver personalized advertising messages has long been a major objective in marketing since it allows marketers to meet heterogeneous consumer needs and target their messages more effectively (Arens & Bovee, 1994). However, traditional one-to-many marketing approaches applied in mass media suffer from their inability to meet this objective (Dibb, 1998; Hoffman & Novak, 1997). In order to increase the efficiency of their strategy, marketers identify homogeneous groups of consumers (market segmentation) which they target according to their marketing objectives. Thus, market segmentation has become the most important marketing tool for targeting purposes (McBurnie & Clutterbuck, 1998), also utilized in the TV advertising domain in conjunction with domain-specific features such as time zones and/or program typologies. However, this strategy has admittedly little to offer towards the ultimate goal of one-to-one communication, since the targeted unit is the segment rather than the individual consumer, and therefore individual needs cannot be satisfied. In the broadcasting television advertising domain, media coverage either exceeds the targeted market segment or leaves potential customers without exposure to the message, thus reducing its cost effectiveness (Belch & Belch, 1995). At the same time, TV viewers have to deal with a vast amount of available advertising information. The issue of information overload, typical in information theoretic terms, is also experienced in the case of TV advertisements as advertising clutter, which has been identified as one of the significant factors associated with the negative attitude of viewers towards advertising and can have a negative impact on television advertisement recall or recognition (Mord & Gilson, 1985). Relevant surveys reveal that 80% of the viewers feel that there is “too much advertising in television” (Elliott & Speck, 1998), while more than 75% of consumers are not happy with the broadcasted advertisements (Hawkins, Best, & Coney, 1998 ). Current target marketing methods are limited in their ability to efficiently target consumers at the individual level, particularly in mass media such as television. Thus, personalization of advertisements provides marketers with the opportunity to increase advertising effectiveness by targeting consumers who are most likely to respond positively to the advertising message. The present article investigates appropriate personalization methods for the domain of digital television advertisements by examining relevant methods utilized for personalized Web applications. In addition, it is concerned with the design of the interactive elements of a typical 30-second advertisement in support of the personalization process. The two objectives of this article are interrelated: the selection of a personalization technique affects the design of interactive advertisements since it indicates the type of interaction data that should be collected in order to enable personalization. The next section of this article opens up the discussion on personalization from a theoretical point of view and in the following section specific personalization techniques are compared. Next, the types of interaction data required to achieve personalization are discussed and the article concludes with further discussion and conclusions.

Reports

  1. Chorianopoulos, K. and Giannakos, M.N. 2012. Practices and technologies for collaborative informal learning in Remote Schools. Ionian University, Greece, Corfu.
    Project CULT aims to create a cooperation platform (hardware/software/practices) for the benefit of schools that reside in remote (rural, islands) areas. For this purpose, we are employing both established and novel interaction and communication technologies. Moreover, we are working closely with schools and teachers, in order to leverage their ability to adopt and adapt technologies in ways that are suitable for their skills and needs. In particular, we have shaped our understanding about remote schools by means of an extended cultural probes study, which was administered during the first part of the research. Then, we have established a series of local workshops that involved teachers in the adoption and adaptation of novel technologies in ways that are suitable for them. Moreover, we have developed and evaluated novel user interfaces for interactive whiteboards that facilitate collaborative learning, as well as a video assisted distance learning system.
  2. Chorianopoulos, K. 2004. Virtual television channels: Conceptual model, user interface design and affective usability evaluation. {PhD} Athens University of Economics and Business, 198. http://phdtheses.ekt.gr/eadd/handle/10442/17648.
    This doctoral dissertation aims to investigate user interface (UI) design, implementation and evaluation for interactive television (ITV) applications. Computer mediated entertainment (e.g. video-games, digital music, DVD movies, ITV) has emerged as a major economic factor in the media industry, taking-up a large portion of consumer spending and leisure time. Advances in set-top box technology made possible the digital video recorder (DVR) and Internet connectivity, thus making the television interactive. The objective of the present work is to evaluate the established human-computer interaction (HCI) theory against the requirements of ITV applications. Previous HCI research about ITV focused only on the design of the electronic program guide (EPG) and did not consider the enhancement of the TV content. Furthermore, previous research approached ITV from a single perspective (e.g. computer engineering, advertising, communication) and it did not consider the conflicts of interest between the broadcasters and the consumers, between the developers and the producers, and more crucially, it did not consider the ITV user as a TV viewer. For this purpose, the established TV watching behavior is identified in other scientific disciplines, such as advertising and communication, and it is combined with the Information Technology (IT) usability mentality. The design methodology involves two phases. The objective of the first design phase is to formulate a small set of principal elements that are generic to the design of ITV UIs, such as Virtual Channel conceptual model, UI principles, UI development toolkit, prototyping platform, and affective usability evaluation framework. The objective of the second design phase is to employ the elements identified in the previous stage into the development of an ITV application. The ITV application was evaluated by consumers and addressed three contemporary UI issues: video skipping, animated character, and dynamic advertisement insertion. Overall, the methodology employed a holistic design approach for ITV applications, in which the UI model and the business model were systematically mapped to and validated through an ITV music application. In brief, it was found that the track-skipping UI seamlessly enhanced consumer entertainment. Moreover, it was found that an animated character is preferred, when compared with the traditional transparent box for the presentation of related information. Consumers evaluated the dynamic advertisement insertion positively, thus, opening-up many opportunities for novel advertising formats. The employment of the proposed HCI elements made the design and the development of the ITV application a straightforward process and produced an entertainment experience that was liked by the consumers. The results entail significant implications for the TV industry. ITV is currently perceived as a set of decorative elements, which do not provide any actual improvement of the existing TV content. On the other hand, video-skipping is a familiar functionality that should be exploited, instead of neglected due to the fear of cannibalizing the fixed advertising of the broadcast schedules. The dynamic advertisement insertion in the TV content stream offers a novel advertising format. Finally, there are opportunities for a new mediating role in the media industry that combines the available broadcast transmission with additional elements (Internet resources, computer generated graphics) for the provision of personalized virtual television channels.