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2009 | Buch

Human-Computer Interaction – INTERACT 2009

12th IFIP TC 13 International Conference, Uppsala, Sweden, August 24-28, 2009, Proceedings, Part I

herausgegeben von: Tom Gross, Jan Gulliksen, Paula Kotzé, Lars Oestreicher, Philippe Palanque, Raquel Oliveira Prates, Marco Winckler

Verlag: Springer Berlin Heidelberg

Buchreihe : Lecture Notes in Computer Science

insite
SUCHEN

Über dieses Buch

INTERACT 2009 was the 12th of a series of INTERACT international c- ferences supported by the IFIP Technical Committee 13 on Human–Computer Interaction. This year,INTERACT washeld in Uppsala (Sweden), organizedby the Swedish Interdisciplinary Interest Group for Human–Computer Interaction (STIMDI) in cooperation with the Department of Information Technology at Uppsala University. Like its predecessors, INTERACT 2009 highlighted, both to the academic and to the industrial world, the importance of the human–computer interaction (HCI) area and its most recent breakthroughs on current applications. Both - perienced HCI researchers and professionals, as well as newcomers to the HCI ?eld, interested in designing or evaluating interactive software, developing new interaction technologies, or investigating overarching theories of HCI, found in INTERACT 2009 a great forum for communication with people of similar int- ests, to encourage collaboration and to learn. INTERACT 2009 had Research and Practice as its special theme. The r- son we selected this theme is that the research within the ?eld has drifted away from the practicalapplicability of its results and that the HCI practice has come to disregard the knowledge and development within the academic community.

Inhaltsverzeichnis

Frontmatter

Part One: Keynote Speakers

Mobile Life – Innovation in the Wild

After a decade of work in our research labs on mobile and ubiquitous technology, often formed by the early visions of ubiquitous computing, with the urge to move interaction from the desktop out into the wild, these technologies have now moved out into the world - into the wild. We are in the middle of a second IT-revolution, caused by the spread of mobile and ubiquitous services, in combination with a broad consumer-oriented market pull. The first ITrevolution, the introduction and deployment of Internet and the World Wide Web during the 1990’s, had a major impact on all parts of our society. As mobile, ubiquitous technology now becomes wide-spread, the design and evaluation of mobile services - i.e. information technology that can be accessed and used in virtually any setting - represents an important business arena for the IT- and telecom industry. Together we have to look for a sustainable web of work, leisure and ubiquitous technology we can call the mobile life.

Kristina Höök
Towards Human-Centred Design

The field of HCI has evolved and expanded dramatically since its origin in the early 1980’s. The HCI community embraces a large community of researchers and practitioners around the world, from a variety of disciplinary backgrounds in the human and social sciences, engineering and informatics, and more recently, the arts and design disciplines. This kaleidoscope of cultures and disciplines as seen at INTERACT Conferences provides a rich pool of resources for examining our field. Applications are increasingly exploring our full range of sensory modalities, and merging the digital and physical worlds. WiFi has opened up a huge design space for mobile applications. A focus on usability of products and services has been complemented by an emphasis on engagement, enjoyment and experience. With the advent of ubiquitous computing, and the emergence of “The Internet of Things”, new kinds of more open infrastructures make possible radically new kinds of applications. The sources of innovation have also broadened, to include human and social actors outside of the computing and design organizations. The question is to what extent is our mainstream thinking in the HCI field ready for the challenges of this Brave New World? Do the technological and social innovations that we see emerging require us to re-shape, or even, re-create, our field, or is it a case of a more gradual evolution and development of that which we already know? In this closing Keynote, I will provide a perspective on the evolution and development of the HCI field, looking backwards as well as forwards, in order to determine what are some of the changes of significance in the field. This “broad-brush” approach to what I term “ human-centred design” will be complemented by the examination of specific projects and applications, to help anchor some of the discussion. Areas such as user-centred design, participatory design, computer-supported cooperative work and learning, and interaction design, in which I have had some involvement over the years, will be mentioned. I will discuss the themes of “ecologies of artefacts”, appropriation, tinkering/bricolage, and the emergence of design anthropology, among other topics. The purpose of the talk is not to engage in a form of Futurism concerning the HCI field, but to examine some of the technical and social trends that can be observed, and to highlight some areas of particular significance that warrant further attention. I argue for a multi-layered approach that, while exploring new avenues of research concerning people’s use of technology, does not necessarily dismiss the corpus of knowledge we have built up over the years concerning human-computer interaction. From a personal perspective, issues such as means and ends, our underlying values, and concern for our fellow human beings in an increasingly fragile world, are issues that, while perhaps seen as outside the remit of a narrow HCI brief, impact on the field in significant ways. In this regard, discussions of our future should not be the preserve of techno-determinists, but be open to all. For example, ubiquitous computing can be involved in many scenarios, not only that of “Ambient Intelligence”. We need to engage in the development and critique of these different perspectives and approaches. Being able to work in and with multidisciplinary teams embodying distint, and at times conflicting perspectives, being able to communicate ones ideas and information across a variety of social and institutional boundaries, will become of great importance. Of particular concern, in the context of an IFIP INTERACT event, is the need to balance the heterogeneity of concepts and methods being used in research and practice with some form of quality control. Despite the heterogeneity of perspectives and disciplines nowadays involved in the field, I will argue that the HCI community, as a community, still does have a significant role to play in the development and evolution of useful, usable and enaging ICT-enabled infrastructures and applications.

Liam J. Bannon

Part Two: Long and Short Papers

Accessibility 1

DTorial: An Interactive Tutorial Framework for Blind Users in a Web 2.0 World

Effective tutorial systems can help promote products by reducing barriers of learning new applications. With dynamic web applications becoming as complex as desktop programs, there is a growing need for online tutorial/help systems. For visually impaired users the key limitations of traditional help systems are 1) poor access to help content with assistive technology, and 2) frequent reliance on videos/images to identify parts of web applications and demonstrate functionality. In this paper, we present a new interaction model, targeted towards screen-reader users, that describes how to embed an interactive tutorial within a web application. The interaction model is demonstrated within a system called DTorial, a fully functional dynamic audio-based tutorial with embedded content. While remaining within the web application, users can rapidly access any tutorial content, injected inline near relevant application controls, allowing them to quickly apply what they just heard to the application itself, without ever losing their position or having to shift windows. The model and implementation are grounded in sighted user help-systems literature and an analysis of screen-reader and Web-Application interactions. Lessons learned from the incremental design and evaluations indicate that providing visually impaired users with dynamic, embedded, interactive audio-based tutorial systems can reduce the barriers to new Web-Applications.

Joshua Hailpern, Loretta Guarino Reid, Richard Boardman
The Attentive Hearing Aid: Eye Selection of Auditory Sources for Hearing Impaired Users

An often-heard complaint about hearing aids is that their amplification of environmental noise makes it difficult for users to focus on one particular speaker. In this paper, we present a new prototype Attentive Hearing Aid (AHA) based on ViewPointer, a wearable calibration-free eye tracker. With AHA, users need only look at the person they are listening to, to amplify that voice in their hearing aid. We present a preliminary evaluation of the use of eye input by hearing impaired users for switching between simultaneous speakers. We compared eye input with manual source selection through pointing and remote control buttons. Results show eye input was 73% faster than selection by pointing and 58% faster than button selection. In terms of recall of the material presented, eye input performed 80% better than traditional hearing aids, 54% better than buttons, and 37% better than pointing. Participants rated eye input as highest in the “easiest”, “most natural”, and “best overall” categories.

Jamie Hart, Dumitru Onceanu, Changuk Sohn, Doug Wightman, Roel Vertegaal
Video Gaming for Blind Learners School Integration in Science Classes

In this study we evaluate how the use of audio-based technology can facilitate school integration of blind learners through the interaction with a science videogame. This experience consisted of designing and implementing

The Natomy’s Journey Game

to be played by blind and sighted middle school students. The use of the videogame and its impact on the integration of blind learners into mainstream schools was also evaluated, through the participation of both teachers and learners. In the end, the goal was for blind learners to be able to interact and become socially integrated through active science video gaming and the application of specific science content. The results of this study provide initial data and evidence that the use of video games such as

The Natomy’s Journey Game

can improve the process for the school integration of learners with visual disabilities.

Jaime Sánchez, Mauricio Sáenz

Accessibility 2

Speech-Based Navigation: Improving Grid-Based Solutions

Speech-based technology is a useful alternative to traditional input techniques such as the keyboard and mouse. For people with disabilities that hinder use of traditional input devices, a hands-free speechbased interaction solution is highly desirable. Various speech-based navigation techniques have been discussed in the literature and employed in commercial software applications. Among them, grid-based navigation has shown both potential and limitations. Grid-based solutions allow users to position the cursor using recursive grids to ‘drill down’ until the cursor is in the desired location. We report the results of an empirical study that assessed the efficacy of two enhancements to the grid-based navigation technique: magnification and fine-tuning. Both mechanisms were designed to facilitate the process of selecting small targets. The results suggest that both the magnification and the fine-tuning capabilities significantly improved the participants’ performance when selecting small targets and that fine-tuning also has benefits when selecting larger targets. Participants preferred the solution that provided both enhancements.

Shaojian Zhu, Yao Ma, Jinjuan Feng, Andrew Sears
Useful, Social and Enjoyable: Mobile Phone Adoption by Older People

The paper presents an empirical model of acceptance of mobile phones by elderly people. It is based on an extension of the widely used TAM-Technology Acceptance Model and aims specifically at investigating the relationship among intrinsic and extrinsic motivations to use. The data consists of 740 questionnaires from people over 65 years old. The validated model shows that intrinsic motivations play an important role albeit always mediated by utilitarian motives. Similarly, it emerges a strong influence of the reference social group (children and relatives) in increasing the utilitarian values of the use of mobile phones. These findings suggest that mobile phone usage by elderly might not be, after all, too much different, from a motivational point of view, from that of younger or adult people.

Mario Conci, Fabio Pianesi, Massimo Zancanaro
Overview of Behaviour Characteristics of High and Low Literacy Users: Information Seeking of an Online Social Service System

We investigated the differences in information seeking behaviours between low and high literacy users on an on-line social service system called the “Adviseguide” website. Ten volunteers participated in the study. Using the UK’s National Skills for Life Survey, five were classified as high literate; five as low literate. Participants had four information search tasks that vary in difficulty: easy, medium and difficult. Observations, video recording, and a semi structured interview technique were used. The data were analysed using Grounded Theory and Emergent Themes Analysis approach. We identified eight information seeking behaviour characteristics; Reading/ Scanning, Focus, Satisfied, Verification, Recovery, Trajectories, Representation and Abandon. Results showed that low and high literacy users demonstrated critically different characteristics.

Neesha Kodagoda, B. L. William Wong, Nawaz Kahan
‘I Have Something to Say’: Supporting Aphasics for Organizing and Sharing Personal Experiences by Photos

When a person, due to brain injury or other disease, suffers in his or her ability to speak, it becomes inherently cumbersome to share needs, emotions, and experiences through personal stories and social interaction. We report on our early design exploration to share everyday experiences by photos for people having expressive aphasia. We also introduce the concept of a multimodal narrative template to help persons with aphasia to reconstruct their experiences and hence promote face-to-face communication and social interaction from everyday activities.

Abdullah Al Mahmud, Jean-Bernard Martens

Affective HCI and Emotion

The Attractiveness Stereotype in the Evaluation of Embodied Conversational Agents

Physical attractiveness is an important cue for social interaction. Psychology studies have long shown that physical attractiveness can elicit positive personality attributions as well as positive behaviour towards other people. This effect is explained by the attractiveness stereotype. In this paper, we investigate whether this stereotype apply to the interaction with virtual agents. We report the results of two experiments where the attractiveness stereotype was tested with and without interaction with the agent. Results indicate a strong effect of the attractiveness stereotype, showing that users tend to form and maintain a better evaluation of attractive agents than of unattractive ones independent of actual interaction with the agent or the agents’ ethnicity. Implications for design are discussed.

Rabia Khan, Antonella De Angeli
Interpreting Human and Avatar Facial Expressions

This paper investigates the impact of contradictory emotional content on people’s ability to identify the emotion expressed on avatar faces as compared to human faces. Participants saw emotional faces (human or avatar) coupled with emotional texts. The face and text could either display the same or different emotions. Participants were asked to identify the emotion on the face and in the text. While they correctly identified the emotion on human faces more often than on avatar faces, this difference was mostly due to the neutral avatar face. People were no better at identifying a facial expression when emotional information coming from two sources was the same than when it was different, regardless of whether the facial expression was displayed on a human face or on an avatar face. Finally, people were more sensitive to context when trying to identify the emotion in the accompanying text.

Sylvie Noël, Sarah Dumoulin, Gitte Lindgaard
Emotional Bandwidth: Information Theory Analysis of Affective Response Ratings Using a Continuous Slider

Emotions are an important part of the user experience in human machine interaction. More standardized methods of emotion measurement are required to assist in evaluating and comparing these experiences. This research introduces the concept of Emotional Bandwidth, a psychometric property of self-reported emotion measured through a continuous, quantitative slider. Emotional Bandwidth is illustrated in a videoconference watching case study. The Shannon-Weaver measure of informational entropy was used to quantify the rating usage bandwidth, which relates to the number of levels of emotional rating effectively utilized by participants. Significant differences in rating usage strategy were found, with four groups being identified; across the four experimental blocks, entropy either increased, decreased, remained constant or irregular. Emotional Bandwidth, the information-theoretic analysis of affect ratings collected with a continuous slider, may be used to characterize changes in participants’ emotional self-rating during experiments and evaluations.

Danielle Lottridge, Mark Chignell
Can You Be Persuaded? Individual Differences in Susceptibility to Persuasion

Persuasive technologies are growing in popularity and many designers create systems which intentionally change users attitudes or behaviors. This study shows that peoples individual differences in susceptibility to persuasion, as implemented using the six persuasion principles proposed by Cialdini 2, relates to their compliance to a persuasive request which is accompanied by a persuasive cue. This result is a starting point for designers to start incorporating individual differences in susceptibility to persuasive cues in their adaptive persuasive systems.

Maurits Kaptein, Panos Markopoulos, Boris de Ruyter, Emile Aarts
The Subjective and Objective Nature of Website Aesthetic Impressions

This paper explores the possibility to predict positive aesthetic impression and user preference of website design through a combination of objective and subjective factors. The objective factors used are symmetry, order, balance, complexity while the subjective ones include familiarity - novelty ratings. The advantages of such an approach is the reduction of user involvement since the ratings of objective factors may be provided by a small number of design experts. We found indications that balance between certain factors maximize the possibility of users having a positive aesthetic impression.

Eleftherios Papachristos, Nikolaos Avouris

Child Computer Interfaces

Biting, Whirling, Crawling - Children’s Embodied Interaction with Walk-through Displays

Understanding of embodied interaction in the context of walk-through displays and designing for it is very limited. This study examined children’s intuitive embodied interaction with a large, semi-visible, projective walk-through display and space around it using observation. We identified several interaction patterns for passing, staying and moving inside the screen, using whole body and its parts for manipulating surface and content on the screen, and ways of expanding the actual interaction environment outside of the projected screen. We summarize the interaction patterns in the form of palette for rich embodied interaction with projected walk-through displays.

Satu Jumisko-Pyykkö, Mandy Weitzel, Ismo Rakkolainen
Causes of Simultaneous Keystrokes in Children and Adults

Simultaneously pressing two keys on a keyboard (Zero Time keystrokes) is a unique typing occurrence. To understand the cause of Zero Time keystrokes, typing data were collected from young children and undergraduate computing students. The results show that, in both students and children, the most frequent cause of Zero Time keystrokes were errors in aiming for the intended key, resulting in the intended and an adjacent key being pressed together. The second most frequent errors were Transposition Errors, which were errors in the ordering of the intended two letters.

Akiyo Kano, Janet C. Read
Evaluating a Tangible Game Video Console for Kids

Tangible and tabletop interaction can be suitable for kindergarten children as educational material, expressive tool, or merely for fun. But only playfully interactive experiences will happen if technologies include aspects that are relevant to the child’s development, incorporating social experiences and easy control. Observation of children using these technologies is an important feedback to improve designs but an appropriated method has to be used in the evaluations. The Structured Expert Evaluation Method (SEEM) not only assesses technologies’ usability but also fun aspects. This paper presents our research about the design and evaluation of a tabletop prototype oriented to children between 3 and 6 years, and the analysis of observations of children using our games.

Javier Marco, Eva Cerezo, Sandra Baldassarri
Exploring Geometric Shapes with Touch

We propose a new technique to help users to explore geometric shapes without vision. This technique is based on a guidance using directional cues with a pin array. This is an alternative to the usual technique that consists of raising the pins corresponding to dark pixels around the cursor. In this paper we compare the exploration of geometric shapes with our new technique in unimanual and bimanual conditions. The users made fewer errors in unimanual condition than in bimanual condition. However they did not explore the shapes more quickly and there was no difference in confidence in their answer.

Thomas Pietrzak, Andrew Crossan, Stephen A. Brewster, Benoît Martin, Isabelle Pecci
Gender and Cultural Differences in Perceiving Game Characters of Digital Educational Games

A survey on the initial design of a digital educational game was developed and administered to the target group in Germany and England. Some significant gender and cultural differences in game play habit, game type preferences and game character perceptions were observed.

Effie Lai-Chong Law, Tim Gamble, Daniel Schwarz

Ethics and Privacy

Staging Urban Interactions with Media Façades

Using media façades as a subcategory of urban computing, this paper contributes to the understanding of spatial interaction, sense-making, and social mediation as part of identifying key characteristics of interaction with media façades. Our research addresses in particular the open-ended but framed nature of interaction, which in conjunction with varying interpretations enables individual sense-making. Moreover, we contribute to the understanding of flexible social interaction by addressing urban interaction in relation to distributed attention, shared focus, dialogue and collective action. Finally we address challenges for interaction designers encountered in a complex spatial setting calling for a need to take into account multiple viewing and action positions. Our research-through-design approach has included a real-life design intervention in terms of the design, implementation, and reflective evaluation of a 180 m

2

(1937 square feet) interactive media façade in operation 24/7 for more than 50 days.

Martin Brynskov, Peter Dalsgaard, Tobias Ebsen, Jonas Fritsch, Kim Halskov, Rune Nielsen
Location-Based Services and Privacy in Airports

This paper reports on a study of privacy concerns related to location-based services in an airport, where users who volunteer for the service will be tracked for a limited period and within a limited area. Reactions elicited from travellers at a field trial showed 60% feeling to some or to a large degree more secure with the system in operation. To provide a background for the privacy study we also describe services provided by the tracking facility and the infrastructure behind it as well as the design and evaluation activities we used. Based on project results including a large number of comments from passengers, we discuss factors influencing passengers’ acceptance and appreciation of location-based services in airports.

John Paulin Hansen, Alexandre Alapetite, Henning Boje Andersen, Lone Malmborg, Jacob Thommesen
‘I Know That You Know’ - Ascertaining Mutual Awareness of Recipient’s Availability Status in Instant Messaging Applications

This study investigated ways to attain mutual, reciprocal awareness of recipient’s availability status in Instant Messaging (IM) applications. For that purpose we designed, implemented and tested a prototype of an IM system named Do

NT

Bother. The analysis of the quantitative and qualitative results showed that displaying status indication in the chat box encouraged participants to show more respect towards the communicative state of their colleagues comparing to situations, in which the status indication was presented only in the ‘buddy list’ view. These findings empirically confirm the importance of reciprocal awareness as defined by Erickson and Kellogg [12] who argued that, to stimulate social behaviours, systems need to maintain the mutual knowledge of who knows what of the information that is shared among users. The study also showed that mutual awareness needs to be maintained not only during communication initiation but also throughout the entire communication duration. To achieve that Instant Messaging systems need to: (i) support indicating the time frame for answering messages in situations when the recipient is not instantaneously able to engage in a conversation, (ii) support specifying the urgency of a message and also (iii) support indicating communication breakdowns especially if they are caused by a reason occurring outside the application domain.

Agnieszka Matysiak Szóstek, Berry Eggen
Automatic Translation System to Spanish Sign Language with a Virtual Interpreter

In this paper, an automatic translation system from Spanish language into Spanish Sign Language (LSE) performed by a virtual interpreter is presented. The translator is based on rules from Spanish grammar considering the syntactical and morphological characteristics of words and the semantics of their meaning. The system has been incorporated to an animation engine in which a virtual character acts as an interpreter that communicates using LSE. The mood of the interpreter is considered, so that the translation and the signs are modified depending on whether the interpreter is happy, angry, etc. The system has been tested with satisfactory results in speed and quality.

Sandra Baldassarri, Eva Cerezo, Francisco Royo-Santas
Towards an Approach to Ethics and HCI Development Based on Løgstrup’s Ideas

Concurrent with interactive technologies playing an increasingly large part of the lives of people all over the world, ethical reflections concerning the use of such technology are becoming more and more important. Most often ethical evaluations of a technology are based on either a utilitarian or a deontological approach. Both kinds of approaches to the ethics of information technology appear to be inadequate. This paper suggests an alternative based on the works of the Danish philosopher K.E. Løgstrup (1905-1981). On this basis it is argued that an attitude change is required amongst the developers of interactive technologies in order for new technologies to be developed in a truly ethical manner.

Sandra Burri Gram-Hansen

Evaluation 1

Evidence Based Design of Heuristics for Computer Assisted Assessment

The use of heuristics for the evaluation of interfaces is a well studied area. Currently there appear to be two main research areas in relation to heuristics: the analysis of methods to improve the effectiveness of heuristic evaluations; and the development of new heuristic sets for novel and specialised domains. This paper proposes an evidence based design approach to the development of domain specific heuristics and shows how this method was applied within the context of computer assisted assessment. A corpus of usability problems was created through a series of student surveys, heuristic evaluations, and a review of the literature. This corpus was then used to synthesise a set of domain specific heuristics for evaluating CAA applications. The paper describes the process, and presents a new set of heuristics for evaluating CAA applications.

Gavin Sim, Janet C. Read, Gilbert Cockton
Physical Fidelity: Exploring the Importance of Physicality on Physical-Digital Conceptual Prototyping

The physicality of digital-physical devices is an essential part of our interaction and understanding of information appliances. This paper draws on the findings of an empirical study investigating the effect of physical fidelity on a series of user trials. Three prototypes of a single design intent were built, the standard of their construction dictated by the time imposed on the designer. In choosing this constraint, the authors present the argument that the most important driver in decisions that dictate fidelity levels is the available and/or necessary time required for making a prototype in order to generate information of the right quality. This paper presents the empirical and qualitative results of the trials, which suggest that there is little effect of fidelity on user performance, but the user’s ability to give constructive feedback on the design was influenced by the nature of the prototypes.

Joanna Hare, Steve Gill, Gareth Loudon, Devina Ramduny-Ellis, Alan Dix
Considering Cost in Usability Evaluation of Mobile Applications: Who, Where and When

As computing moves from desktop to outdoor everyday life activities, usability evaluation must take into account new aspects, related with mobility and space. In this paper the effectiveness of established usability evaluation methods is examined through an extensive case study. The usability of an educational mobile museum application was tested using three different methods: inspection by experts, use in lab setting and use in the field. Results indicate that each method uncovers different types of problems at different cost. We believe that a combination of these methods may be worthwhile since their produced results seem to be complementary.

Georgios Fiotakis, Dimitrios Raptis, Nikolaos Avouris
Is the ‘Figure of Merit’ Really That Meritorious?

Studies comparing performance of Usability Evaluation Methods (UEMs) led to three standard metrics, namely, validity, thoroughness, and effectiveness, calculated from lab-based usability test results. The effectiveness metric, E = T × V, was proposed as the ‘figure of merit’ [7] that would give a balanced account of validity and thoroughness. This paper provides an analysis of the formula to caution future researchers and usability practitioners against its use, proposes an alternative formula, and discusses the limitations of the common baseline approach to UEM comparison.

Jarinee Chattratichart, Gitte Lindgaard
User-Centered Evaluation of the Responsiveness of Applications

This paper presents an approach to evaluating the responsiveness of soft ware applications from a ’user’s perspective, which has been developed and applied at SAP AG, Ger many, a leading manufacturer of business soft ware. The approach is based on human time ranges and compares actual with toler able response times, mea sured using standardized application scenarios.

Gerd Waloszek, Ulrich Kreichgauer
Evaluation of User Interface Design and Input Methods for Applications on Mobile Touch Screen Devices

With the advent of touch screen phones, good UI design and simplified input methods for applications running on such devices are important factors that contribute to its popularity and success. The goal of this research is to evaluate different user interface designs and input methods for mobile phones with touch screen capability. In order to do this, two prototypes of a simple social networking application were implemented using a G1 phone that runs the Android platform. A user study has been conducted to compare different input techniques and UI designs and evaluate their usability.

Florence Balagtas-Fernandez, Jenny Forrai, Heinrich Hussmann

Evaluation 2

Multi-format Notifications for Multi-tasking

We studied people’s perception of and response to a set of visual and auditory notifications issued in a multi-task environment. Primary findings show that participants’ reactive preference ratings of notifications delivered in various contexts during experimentation appear to contradict their reflective, overall ratings of the notification formats when elicited independently of contextual information, indicating a potential difficulty in people’s abilities to articulate their preferences in the absence of context. We also found people to vary considerably in their preferences for different notification formats delivered in different contexts, such that simple approaches to selecting notification delivery formats will be dissatisfying to users a substantial portion of the time. These findings can inform the designs of future systems: rather than target the general user alone, they should strive to better understand each user individually.

Julie S. Weber, Mark W. Newman, Martha E. Pollack
Making Pen-Based Operation More Seamless and Continuous

The feature of continuous interaction in pen-based system is critically significant. Seamless mode switch can effectively enhance the fluency of interaction. The interface which incorporated the advantages of seamless and continuous operation has the potential of enhancing the efficiency of operation and concentrating the users’ attention. In this paper, we present a seamless and continuous operation paradigm based on pen’s multiple-input parameters. A prototype which can support seamless and continuous (SC) operation is designed to compare the performance with MS Word 2007 system. The subjects were requested to select target components, activate the command menus and color the targets with a given flowchart in two systems respectively. The experiment results report the SC operation paradigm outperformed the standard ways in MS Word in both operation speed and cursor footprint length (CFL).

Chuanyi Liu, Xiangshi Ren
Insight into Goal-Directed Movements: Beyond Fitts’ Law

Various methods and measures have been developed to assess the quality of input devices and interaction techniques. One approach to investigating the performance of input devices and interaction techniques is to focus on the quality of the produced movements. The current paper proposes a new method of analyzing goal-directed movements by dividing them into meaningful phases. In addition to the proposed analysis method a selection of measures is suggested to assess different aspects of rapidly aimed movements. In order to evaluate the added value of the proposed analysis method an experiment has been conducted to compare two input devices (mouse versus stylus with tablet) with respect to their performance on a multi-directional pointing task. The results show that the analysis into several phases reveals clear differences in the movement strategy.

Karin Nieuwenhuizen, Dzmitry Aliakseyeu, Jean-Bernard Martens
A Model to Simulate Web Users’ Eye Movements

One of the most important tasks on the Web is foraging information. In this study, we present a computational model which simulates human eye movements during information seeking in Web pages. Human visual scanpaths are guided by their information needs, by the visual features of the stimuli and by what they previously processed. Our model takes into account both semantic (top-down) and visual (bottom-up) information, as well as a memory model in order to predict the focus of attention. Our model operates at the block level, but also at the word level. To validate this model, both participants and model were asked to seek information in a pseudo online newspaper. We find good correspondence between simulated and empirically observed scanpaths. Knowing where the user is looking at while searching for information is crucial for evaluating the usability of Web sites and contribute to the design of Web pages.

Myriam Chanceaux, Anne Guérin-Dugué, Benoît Lemaire, Thierry Baccino

Games, Fun and Aesthetic Design 1

Balancing Skills to Optimize Fun in Interactive Board Games

Playing games against people with a different skill level can be boring or frustrating, which decreases fun. A solution is to introduce specific rules that balance a game. In this paper we describe a study in which we used an electronic board game with tangible interaction to investigate whether balancing a game indeed increases fun experienced. We also investigate whether balancing skill levels implicitly (players are unaware) or explicitly (players are aware) has an influence on the fun experienced. We found that players who lost a game felt more successful in the balanced game compared to the unbalanced game. The balanced game also offered the players more fun experience than they expected beforehand. Finally, players preferred to play an explicitly balanced game because it increased the feeling of effort and challenge.

Eva Kraaijenbrink, Frank van Gils, Quan Cheng, Robert van Herk, Elise van den Hoven
For Your Eyes Only: Controlling 3D Online Games by Eye-Gaze

Massively multiplayer online role-playing games, such as World of Warcraft, have become the most widespread 3D graphical environments with millions of active subscribers worldwide. People with severe motor impairments should be able to take part in these games without the extent of their disability being apparent to others online. Eye gaze is a high bandwidth modality that can support this. We have developed a software device that uses gaze input in different modes for emulating mouse and keyboard events appropriate for interacting with on-line games. We report an evaluation study that investigated gaze-based interaction with World of Warcraft using the device. We have found that it is feasible to carry out tasks representative of game play at a beginners skill level using gaze alone. The results from the locomotion task part of the study show similar performance for gaze-based interaction compared with a keyboard and mouse. We discuss the usability issues that arose when completing three types of tasks in the game and the implications of these for playing of this type of game using gaze as the only input modality.

Howell Istance, Aulikki Hyrskykari, Stephen Vickers, Thiago Chaves
Situating Productive Play: Online Gaming Practices and Guanxi in China

Economic activities in and around online gaming in China are often correlated in the West with practices of gold farming, or selling in-game currency to players for real money in online games. What can we learn about online gaming in China and about online gaming and online sociality more broadly when we look at economic and other “pragmatic” practices through which online gaming becomes meaningful to players? In this paper, we present findings from an ethnographic study of online gaming in China’s urban Internet cafes to discuss implications for game design, and HCI design more broadly. Considering the ties between socio-economic practices, development of trust and culturally situated imaginings of self-hood and otherness, brings to the fore how online gaming in and of itself constitutes the means for practical achievements in day-to-day management of

guanxi

(social connection).

Silvia Lindtner, Scott Mainwaring, Paul Dourish, Yang Wang

Games, Fun and Aesthetic Design 2

Head Tracking in First-Person Games: Interaction Using a Web-Camera

Recent advances in face-tracking technology have made it possible to recognize head movements using a commodity web-camera. This development has created exciting possibilities for enhancing player enjoyment during computer game play. In order to ascertain the real-world potential for head gestural input to First Person Shooter games, we have developed seven diverse interaction techniques and integrated these with a modern games engine. Evaluation of the techniques was carried out with four focus groups made up of expert games developers and experienced end-users. One of the techniques was further refined and subjected to a follow-up comparison test with promising results. A set of guidelines for the future development of head interaction techniques for computer games has been derived from the studies. All of the techniques have been built upon freely available software and open-sourced to encourage further research in this area.

Torben Sko, Henry J. Gardner
Playability: How to Identify the Player Experience in a Video Game

Nowadays Video Games occupy a privileged position in the leisure and entertainment market, representing the fastest-growing industry globally. In this paper we will analyse how, in video game development, Usability alone is not sufficient to achieve the optimum Player Experience. We argue that the concept of Usability needs broadening and deepening, to embrace further attributes and properties that identify and describe the Player Experience. We present our proposed means of defining Playability, its attributes and properties and how associate them with the different elements of a video game.

J. L. González Sánchez, N. Padilla Zea, F. L. Gutiérrez
SimCompany: An Educational Game Created through a Human-Work Interaction Design Approach

We present a novel children’s educational game, which was created through a human-work interaction design – an emerging research field which advocates a better understanding of the relationship between work-domain based empirical studies and iterative design of prototypes and new technologies. We describe how “SimCompany”, a game for teaching children about business management concepts, was created. SimCompany proved effective as a teaching tool about business management concepts, and initial evaluation showed a positive increase in students’ rate of learning, compared to traditional teaching methods.

Pedro Campos, Ana Campos

HCI and Web Applications 1

What’s Next? A Visual Editor for Correcting Reading Order

The reading order, i.e. the serialized form, of the webpage should be a meaningful order for alternative representations such as the audible forms needed for visually impaired users. However, the serialized form rarely receives attention because it is visually elusive for authors using the existing WISIWYG authoring environments. Therefore we propose a new visualization technique called “reading flow” that visualizes the order of the serialized form with variable granularity by using a visible path extending through the elements in the content. This allows the authors to instantly evaluate the ordering by the visual pattern of the path. Our approach also allows them to interactively and intuitively reorganize the order of the serialized form. The results of two comparative experiments show that our reading flow greatly increases the ability of the authors to understand and organize the ordering compared to the existing techniques.

Daisuke Sato, Masatomo Kobayashi, Hironobu Takagi, Chieko Asakawa
Looking Ahead: A Comparison of Page Preview Techniques for Goal-Directed Web Navigation

On the World Wide Web, page previews augment hyperlinks to provide extra information about each link’s destination. These previews can reduce navigation time and errors in goal-directed navigation tasks when the information provided by the text and context of links is inadequate. A number of different types of page previews have been proposed, and some are already in use; however, little is known about which preview types will consistently help users make good navigation decisions. Our study compares six preview techniques (title, URL, subject category, page genre, genre symbol, and thumbnail), two delivery mechanisms (inline and popup), and two page load times (fast and slow). We found that previews showing the genre of the page (e.g., whether the page is an information page or a search page) yielded significantly faster performance than other preview techniques, and participants also preferred the genre-based previews. Our study is the first to compare the performance of a wide range of page previews in a naturalistic, non-search environment, and provides empirical data that can improve support for goal-directed navigation.

Aaron Genest, Carl Gutwin, Adrian Reetz, Regan Mandryk, David Pinelle, Andre Doucette
Comparison of Tag Cloud Layouts: Task-Related Performance and Visual Exploration

Tag clouds have become a popular visualization and navigation interface on the Web. Despite their popularity, little is known about tag cloud perception and performance with respect to different user goals. This paper presents results from a comparative study of several tag cloud layouts. The results show differences in task performance, leading to the conclusion that interface designers should carefully select the appropriate tag cloud layout according to the expected user goals. Furthermore, the analysis of eye tracking data provides insights into the visual exploration strategies of tag cloud users.

Steffen Lohmann, Jürgen Ziegler, Lena Tetzlaff

HCI and Web Applications 2

Bringing Web 2.0 to the Old Web: A Platform for Parasitic Applications

It is possible to create interactive, responsive web applications that allow user-generated contributions. However, the relevant technologies have to be explicitly deployed by the authors of the web pages. In this work we present the concept of parasitic and symbiotic web applications which can be deployed on arbitrary web pages by means of a proxy-based application platform. Such applications are capable of inserting, editing and deleting the content of web pages. We use an HTTP proxy in order to insert JavaScript code on each web page that is delivered from the web server to the browser. Additionally we use a database server hosting user-generated scripts as well as high-level APIs allowing for implementing customized web applications. Our approach is capable of cooperating with existing web pages by using shared standards (e.g. formatting of the structure on DOM level) and common APIs but also allows for user-generated (parasitic) applications on arbitrary web pages without the need for cooperation by the page owner.

Florian Alt, Albrecht Schmidt, Richard Atterer, Paul Holleis
Are Ten Participants Enough for Evaluating Information Scent of Web Page Hyperlinks?

Information scent of hyperlinks, that is the user’s assessment of semantic relevance of navigation options in a webpage, has been identified as a critical factor in Web navigation. An important question in this context is to identify the minimum number of participants required to measure reliably information scent. A two phase study was conducted in an attempt to provide an answer to this question. In the first phase, involving 101 participants, ratings produced by different size subsets of participants were compared to those of the whole set. In the second phase, the ratings of these different size subsets of participants where compared with measures of behavior of 54 participants, who performed the same information navigation tasks using a typical web browser. Results indicate that representative estimates of information scent can be obtained from 10 participants in both cases. This finding has important implications for future scent-related studies.

Christos Katsanos, Nikolaos Tselios, Nikolaos Avouris
Navigational Consistency in Websites: What Does it Mean to Users?

A study was conducted to investigate the effects of navigational inconsistencies in websites on users’ perceptions and performance. Of four inconsistencies manipulated (position of navigational bar, order of elements in navigational bar, font type and size of elements), only the position of the bar had a substantial effect. However this affected both users’ perception of their performance and their actual performance, in terms of the time spent on webpages. The mean time spent on the page with the inconsistently positioned navigational bar more than doubled and this effect persisted over subsequent pages. The methodology developed provides a useful way of investigating the effects of navigational inconsistency, an under-studied phenomenon.

Helen Petrie, George Papadofragkakis, Christopher Power, David Swallow
CloudMonster: Support Flexible Browsing and Searching within Music Collections

Studies in the field of Music Information Retrieval (MIR) have shown that users would like to use multiple criteria simultaneously and additional criteria besides the widely used metadata of artist, album and song. We present our prototype named CloudMonster, which supports flexible browsing and searching within music collections using multiple criteria. In a preliminary evaluation the added flexibility for browsing and searching was highly appreciated and we received valuable suggestions for future research.

Ya-Xi Chen, Matthias Hoyer, Andreas Butz
Combinable Tabs: An Interactive Method of Information Comparison Using a Combinable Tabbed Document Interface

The Tabbed Document Interface (“TDI”) of today’s web browsers is widely considered to be a usability improvement over the previously predominate Single Document Interface (“SDI”). TDI styled interfaces however, especially in mashups or other overlays of different information sets, suffer from a key usability limitation: they cannot show two or more tabbed documents simultaneously. Users are left with the task of quickly switching between tabs when trying to visually compare content. Our contribution is centered on intuitively enabling the comparison of tabbed content via what we coined a Combinable Tabbed Document Interface (“CTDI”). This interface extends TDI to allow tabs to be dragged and dropped onto one another to form a “master tab” whose data page renders a “side by side” view of its combined “sub tabs”. The combined view will revert to the previous form when closing the master tab. It’s a novel solution for those websites that needs to compare information, such as e-commerce sites, online dictionaries, etc. To test the effectiveness of CTDI, we developed an online dictionary called “Engkoo” which puts the concept to practice.

Gonglue Jiang, Chen Zhao, Matthew R. Scott, Fang Zou
Web User Modeling via Negotiating Information Foraging Agent

Information foraging theory lays a good foundation for web user modeling. However, the existing user modeling methods mainly focus on fixed information needs. In the real world, a user’s information goal often evolves, and information foraging is a negotiation process between the user and the system. In this paper, we proposed an agent based approach that modeled the dynamic information seeking process of information foragers

.

Xuehong Tao, Yin-Leng Theng, Terence Ting

Human Cognition and Mental Load 1

Distinguishing Difficulty Levels with Non-invasive Brain Activity Measurements

Passive brain-computer interfaces are designed to use brain activity as an additional input, allowing the adaptation of the interface in real time according to the user’s mental state. The goal of the present study is to distinguish between different levels of game difficulty using non-invasive brain activity measurement with functional near-infrared spectroscopy (fNIRS). The study is designed to lead to adaptive interfaces that respond to the user’s brain activity in real time. Nine subjects played two levels of the game Pacman while their brain activity was measured using fNIRS. Statistical analysis and machine learning classification results show that we can discriminate well between subjects playing or resting, and distinguish between the two levels of difficulty with some success. In contrast to most previous fNIRS studies which only distinguish brain activity from rest, we attempt to tell apart two levels of brain activity, and our results show potential for using fNIRS in an adaptive game or user interface.

Audrey Girouard, Erin Treacy Solovey, Leanne M. Hirshfield, Krysta Chauncey, Angelo Sassaroli, Sergio Fantini, Robert J. K. Jacob
Memorization and Information-Retrieval Behaviors

What is the relationship between memorization of information and the behavior used to retrieve that information? Searching for photos stored on a media is a common activity. Chances are that it is easier to find some types of photos than others. To determine the reason for this, we conducted a user study to clarify the mechanisms people use to retrieve information. We found that the operational patterns differed with the degree of memorization and the types of target photos. In particular, we found that the overall relative positions of target contents and/or the order of the arrangement affect memorization. The difference in operational patterns can be interpreted as a difference in retrieval strategies. These findings should contribute to the field of computer-human interactions, enabling the mechanisms used to retrieve information to be better understood. This understanding should lead to interfaces that can dynamically and appropriately assess user intentions and situations.

Jun-ichiro Watanabe, Youichi Horry
Aspects of Auditory Perception and Cognition for Usable Display Resolution in Data Sonification

Sonification of data via the mapping of values to frequency of sound is an auditory data analysis technique commonly used to display graph information. The goal for any form of graph is to display numerical information with accuracy and neutrality while exploiting perceptual and cognitive processes. Conveying information in frequency of sound is subject to aspects of pitch perception, largely overlooked to date, that can influence these properties of auditory graphing. This paper identifies some of these aspects and describes potential design limitations and opportunities derived from the musical nature of auditory data representations.

Johan Kildal

Human Cognition and Mental Load 2

Simulating Perceptive Processes of Pilots to Support System Design

In this paper we present an approach towards supporting the ergonomic design of aircraft cockpits by predicting the probability that pilots might miss relevant information due to routine learning effects combined with non-adequate placement of display instruments. The approach is based on an executable cognitive pilot model. We focus on the cognitive interaction between (1) rule-based processing of flight procedures, (2) the pilot’s mental model of the current situation and (3) pilot’s attention. The cognitive model is coupled with a formal cockpit design to simulate human-machine interaction during flight procedures. As an example we analyze the perception of automatic flight mode changes.

Andreas Lüdtke, Jan-Patrick Osterloh
Cognitive Load Measurement from User’s Linguistic Speech Features for Adaptive Interaction Design

An adaptive interaction system, which is aware of the user’s current cognitive load (CL), can change its response, presentation and flow of interaction material accordingly, to improve user’s experience and performance. We present a speech content analysis approach to CL measurement, which employs users’ linguistic features of speech to determine their experienced CL level. We show analyses of several linguistic features, extracted from speech of personnel working in computerized incident control rooms and involved in highly complex bushfire management tasks in Australia. We present the results of linguistic features showing significant differences between the speech from the cognitively low load and high load tasks. We also discuss how the method may be used for user interface evaluation and interaction design improvement.

M. Asif Khawaja, Fang Chen, Christine Owen, Gregory Hickey
Using Psychophysiological Measurements in Physically Demanding Virtual Environments

Psychophysiological evaluation of mental workload in human-computer interaction has generally been limited to situations with little physical load. This paper examines the viability of using heart rate, skin conductance, respiration and peripheral skin temperature as psychophysiological indicators in a physically demanding task performed in a simple virtual environment. Respiratory rate was found to be a good indicator of arousal while respiratory rate variability and skin temperature indicated changes in valence.

Domen Novak, Matjaž Mihelj, Marko Munih

Human Error and Safety

Resilience of Interaction Techniques to Interrupts: A Formal Model-Based Approach

In many modern working environments interruptions are commonplace as users must temporarily suspend a task to complete an unexpected intervening activity. As users are faced with more and more sources of information competing for their attention, it is becoming increasingly important to understand how interruptions affect their abilities to complete tasks. This paper introduces a new perspective for research in this field by employing analytical, model-based techniques that are informed by well-established cognitive theories and empirical data available in the literature. We propose stochastic modelling and model checking to predict measures of the disruptive effects of interruptions to two well-known interaction techniques: Drag ’n Drop and Speak ’n Drop. The approach also provides a way to compare the resilience of different interaction techniques to the presence of external interruptions that users need to handle. The obtained results are in a form that allows validation with results obtained by empirical studies involving real users.

Maurice H. ter Beek, Giorgio P. Faconti, Mieke Massink, Philippe A. Palanque, Marco Winckler
Adaptive Security Dialogs for Improved Security Behavior of Users

Despite the increasing awareness of the importance of security for daily computer users, we see that many users still fail to behave securely when confronted with a security-related decision. In this paper, we introduce a new approach to security-related dialogs called Adaptive Security Dialogs (ASD). This approach is a combination of a new architecture and a new way of interacting with users to provide them with appropriate and effective security dialogs. ASD realizes this goal by matching the complexity and intrusiveness of security-related dialogs to the risk associated with the decision the user is making. This results in an architecture in which users can focus on their tasks, get (immediate) feedback on their decisions, and interact with dialogs with an appropriate complexity and appearance for the decision’s associated risk. This paper makes the following three contributions. First, we introduce a general architecture for handling security-related decisions. Second, through an empirical user study using a web-based e-mail client, we show significant improvement in the care exercised by our participants without sacrificing usability. Third, we describe how the different pieces of existing research fit into the bigger picture of improving users’ behavior.

Frederik De Keukelaere, Sachiko Yoshihama, Scott Trent, Yu Zhang, Lin Luo, Mary Ellen Zurko
Perceptions of Risk and Control: Understanding Acceptance of Advanced Driver Assistance Systems

With a marked increase in advanced driver assistance systems (ADAS) being designed and deployed for cars, there is a logical emergence of studies that critically examine the influence these have on driver behavior and attitudes towards risk and safety. The research question addressed within this paper asks to what extent the level of perceived criticality or risk on the part of drivers influences their acceptance of advanced assistance.

Somya Joshi, Thierry Bellet, Vanessa Bodard, Angelos Amditis
Detection of Pilot Errors in Data by Combining Task Modeling and Model Checking

In this paper we show a consistent approach of using Hierarchical Task Analysis together with model checking to identify pilot errors during the interaction with cockpit automation systems in aircraft. Task analysis is used to model flight procedures which describe how to operate a specific system in a particular situation. Afterwards model checking is used to identify deviations from these procedures in empirical simulator data. We envision applying this method to automatically detect pilot errors during flight tests or pilot training.

Florian Frische, Tomasz Mistrzyk, Andreas Lüdtke

Human-Work Interaction Design

Improving the Cost Structure of Sensemaking Tasks: Analysing User Concepts to Inform Information System Design

In many everyday contexts people interact with information systems in order to make sense of a domain of interest. However, what this means and how it can best be supported are poorly understood. In particular, there has been little research on how to develop system representations that simplify naturally occurring sense making processes by matching people’s conceptualizations of the domain. In this paper we draw on Klein et al.’s data-frame theory and Russell at al’s notion of cost-structures in sensemaking to propose an approach to understanding sensemaking that supports reasoning about system requirements. The two key elements of the approach are the identification of the process and the transformational steps within that process that could benefit from support to reduce costs, and the identification of primary concepts which are cued by information in the context of a given sensemaking task and domain, and around which users integrate information to form a structured understanding. Our general principle is that by understanding a sensemaking transformation in terms of its source data and the integrating structures it creates, one is better able to anticipate the evolving information needs that it tends to invoke. We test this approach with a case study of fraud investigation performed by a team of lawyers and forensic accountants and consider how to support the elaboration of prototypical user-frames once they have been invoked.

Simon Attfield, Ann Blandford
Vote and Be Heard: Adding Back-Channel Signals to Social Mirrors

In face-to-face group situations, social pressure and organizational hierarchy relegate the less outspoken to silence, often resulting in fewer voices, fewer ideas, and groupthink. However, in mediated interaction like email, more people join in the discussion to offer their opinion. With this work, we aim to combine the benefits of mediated communication with the benefits and affordances of face-to-face interaction by adding a mediated back-channel. We describe

Conversation Votes

, a tabletop system that augments verbal conversation with a shared anonymous back-channel to highlight agreement. We then discuss a study of our design with groups engaged in repeated discussion. Our results show that anonymous visual back-channels provide a medium for the underrepresented voices of a conversation and balances interaction among all participants.

Tony Bergstrom, Karrie Karahalios
Ownership and Evolution of Local Process Representations

Knowledge workers tailor collaborative business processes to local conditions. They own (i.e., create and maintain) representations of these local processes (such as checklists) to guide the work. Our goal is to design tools to support the ownership of collaborative local processes by enabling workers to flexibly adapt process representations to work situations. This paper focuses on how workers evolve representations for collaborative, locally-owned processes by updating them from situated experiences to keep up with changing business conditions. To understand this, we conducted a field study and a lab study. From the field study, we describe how factors like group roles and documentation purposes affect the evolution of process representations. Based on these observations, we propose a model of the practice of evolving local process representations that provides a framework for understanding activity documentation needs. The lab study then provides behavioral details on the ways people carried out the evolution practice. These studies yield design implications for collaborative activity support tools.

Thomas P. Moran, Tara L. Matthews, Laurian Vega, Barton Smith, James Lin, Stephen Dill
Designing for Improving Verbal Patient Transfer

The current verbal patient transfer between nurses and paramedics lacks communication, which leads to loss of information. During this operation, handwritten protocols are used to document the patient’s personal data and the treatment given at several intervals. In order to encourage teamwork between the two parties (i.e. nurses and paramedics), the challenge is to present the patient information in a more accessible and feasible way. In this paper, we present the design and evaluation of an interactive and tangible presentation medium that aims to improve the verbal patient transfer by mediated communication. Our result shows that the concept would improve the current verbal patient transfer as evaluated by paramedics and nurses.

Abdullah Al Mahmud, Max Eichenbrenner, Omar Mubin
Exploring Manual Interaction and Social Behaviour Patterns in Intensely Collaborative Teamwork

This paper presents the results of a comparative study of 4-person collaborative teams working at a traditional table with pen and paper vs. a multi-touch table with digital keyboards and notepads. We compare the social behaviours of ‘giving’ and ‘taking’ during intensely collaborative teamwork, namely the differences between paper-based behaviour, digital-object based behaviour and a mixed condition behaviour where both paper and digital objects were used. Differences in sharing behaviour may be attributed to the degree of ownership afforded by digital objects on a touch display vs. paper objects. Additional visual metaphors to help tabletop users are recommended.

Natalie Ruiz, Kelvin Cheng, Markus Rittenbruch

Interaction with Small and Large Displays 1

A Comparison of Direct and Indirect Multi-touch Input for Large Surfaces

Multi-touch input on interactive surfaces has matured as a device for bimanual interaction and invoked widespread research interest. We contribute empirical work on direct versus indirect use multi-touch input, comparing direct input on a tabletop display with an indirect condition where the table is used as input surface to a separate, vertically arranged display surface. Users perform significantly better in the direct condition; however our experiments show that this is primarily the case for pointing with comparatively little difference for dragging tasks. We observe that an indirect input arrangement impacts strongly on the users’ fluidity and comfort of ‘hovering’ movement over the surface, and suggest investigation of techniques that allow users to rest their hands on the surface as default position for interaction.

Dominik Schmidt, Florian Block, Hans Gellersen
Evaluating Gaze and Touch Interaction and Two Feedback Techniques on a Large Display in a Shopping Environment

At Philips Research, an Intelligent Shop Window (ISW) was developed. With the ISW, a unique combination is made between a transparent display that is embedded in the window glass, and physical products presented in the shop window. In this paper, touch and gaze interaction with the large display in the ISW are investigated and evaluated. For sensing interfaces it is known that especially with gaze interaction, it is a challenge to communicate to the user that the system is ready and attending to the user, but also which part of the system the user can address. Therefore, two suitable feedback mechanisms for this interaction were designed and evaluated with users. The first was the ’polite products’ concept, where products were placed on a turntable. When the user selects the product with either touch or gaze interaction, the product on the turntable turns towards the user. The second feedback method was a transparent light tile behind the products, which changed color when the product was selected. The evaluation results showed that the polite product concept was rated better than the light tile on almost every item related to hedonic values such as enjoyability and fun. Next to that it became clear that participants felt more in control when using touch interaction and that touch worked faster and more efficient than gaze interaction. However, gaze interaction was a fairly new and exotic interaction method for participants and they said they liked using gaze interaction. Especially the combination of gaze interaction with the polite products feedback method was very strong.

Angelique Kessels, Evert van Loenen, Tatiana Lashina
Design and Evaluation of a Large Interactive Display to Support Social Interaction at Work

Social interaction at work has been shown to enhance creativity and productivity. This paper describes the design and evaluation of a large, interactive display that aims to stimulate social interaction amongst co-workers by providing food for talk in the form of activities, jokes, and music. User and system requirements were collected using Cultural Probes and Focus groups. The evaluation of our prototype system provides valuable insights that may guide the design of future systems supporting social interaction at work.

Sanjin Pajo, Senka Zubić, Agnieszka Matysiak Szóstek, Janienke Sturm
Interactivity for Museums: Designing and Comparing Sensor-Based Installations

Technology today provides exciting new possibilities for creating more appealing museum experiences, since we can exploit the surprise factor of innovative interaction styles to create an engaging experience that facilitates the learning process. This research was based on extensive in-site observation as well as surveys conducted at the scene, and it relates to a cultural interactive exhibition titled “

Cultural Tourism

”. The issues were organized around usability problems detected, social interaction and differences between interaction styles, all of which contribute to increasing our knowledge regarding the use of interactive technology as a means to reduce the distance between visitors and cultural heritage.

Pedro Campos, André Dória, Magno Sousa
Leaf Menus: Linear Menus with Stroke Shortcuts for Small Handheld Devices

This paper presents Leaf menu, a new type of contextual linear menu that supports curved gesture shortcuts. By providing an alternative to keyboard shortcuts, the Leaf menus can be used for the selection of commands on tabletops, but its key benefit is its adequacy to small handheld touchscreen devices (PDA, Smartphone). Indeed Leaf menus define a compact and known layout inherited from linear menus, they support precise finger interaction, they manage occlusion and they can be used in close proximity to the screen borders. Moreover, by providing stroke shortcuts, they favour the selection of frequent commands in expert mode and make eye-free selection possible.

Anne Roudaut, Gilles Bailly, Eric Lecolinet, Laurence Nigay

Interaction with Small and Large Displays 2

Spatial Cues in Small Screen Devices: Benefit Or Handicap?

Disorientation in small-screen-device menus is a frequent problem for many users. This study examines if navigation aids containing spatial information may reduce disorientation. Two aids were implemented into a simulated mobile phone: One aid contained spatial cues, providing an overview of menu locations and routes, the other delivered landmark knowledge, representing salient features on the route. Also, a condition without any aid was examined. 24 children and 24 adults solved four phone tasks twice. Dependent variables were navigation effectiveness and efficiency. Performance was lowest when users were not supported by any aid. The aid providing survey knowledge yielded the best performance. Though, the relative benefit by aids revealed to be age-related. While the aid providing survey knowledge was advantageous for all users, the aid delivering landmark knowledge was especially harmful for the children, which showed considerably more detouring in the menu. It is concluded that navigation aids reduce disorientation in small devices, especially those which support users to build up a spatial representation of the menu.

Martina Ziefle
3DKey: An Accordion-Folding Based Virtual Keyboard for Small Screen

Nowadays, handheld devices are more and more equipped with functionalities and applications so that they almost serve like a desktop computer. However users find them tedious and tiring to input text due the tiny keys of their virtual keyboard. In this paper, we discuss a new text entry method (3DKey) based on addition of a third dimension to traditional virtual keyboard to overcome the small screen constraint of handheld devices. In this context, the accordion-folding the virtual keyboard is used as a solution to expand keys leading to easier selection. Thus our 3DKey virtual keyboard can be seen as composed of two zones: an accordion-folded zone and a spread zone. Our study showed that users achieved more accurate and relatively faster text entry with 120° accordion-folding and predictive spreading virtual keyboard, which resulted in speed improvement of 37.71 %, than with traditional virtual keyboard.

Khaldoun Al Faraj, Mustapha Mojahid, Nadine Vigouroux
Investigating Temporal-Spatial Characteristics of Mouse and Touch Input

This paper explores differences between user actions employing mouse and touch input devices when performing a collaborative task on a tabletop interface. We explore temporal and spatial characteristics of drag actions of users through mouse (indirect) and touch input (direct) devices. Our analysis is based on system-logged interaction data we collected in an exploratory study. The analysis reveals that touch users performed more drag actions than mouse users. Furthermore, touch users dragged artefacts on a tabletop for a shorter period of time than mouse users. At the same time, touch users dragged objects in the workspace shorter distances than mouse users. We also identify differences based on the temporal-spatial histograms of the drag actions. We discuss our findings based on observations we made during the collaborative task and interviews with participants after the study. The results may be related to the performed task and to ergonomic design issues of the setup. We describe the possible implications on co-located and remote collaboration.

Christian Müller-Tomfelde
Adaptive Pointing – Design and Evaluation of a Precision Enhancing Technique for Absolute Pointing Devices

We present Adaptive Pointing, a novel approach to addressing the common problem of accuracy when using absolute pointing devices for distant interaction. First, we discuss extensively some related work concerning the problem-domain of pointing accuracy when using absolute or relative pointing devices. As a result, we introduce a novel classification scheme to more clearly discriminate between different approaches. Second, the Adaptive Pointing technique is presented and described in detail. The intention behind this approach is to improve pointing performance for absolute input devices by implicitly adapting the Control-Display gain to the current user’s needs without violating users’ mental model of absolute-device operation. Third, we present an experiment comparing Adaptive Pointing with pure absolute pointing using a laser-pointer as an example of an absolute device. The results show that Adaptive Pointing results in a significant improvement compared with absolute pointing in terms of movement time (19%), error rate (63%), and user satisfaction.

Werner A. König, Jens Gerken, Stefan Dierdorf, Harald Reiterer

International and Cultural Aspects of HCI

The Perception of Cultural Differences in Online Self-presentation

Online self-presentation, defined as the way people present themselves through profiles, blogs, photo albums, etc., forms the basis of much of the interpersonal relationship building taking place in social networking platforms such as Windows Live Space. However, little is known about how people make sense of this information, particularly if presenter and audience do not have a common cultural background. This study investigated the effectiveness of cross-cultural online communication by measuring the cross-cultural social perception of specially constructed online representations of a typical British and a typical Chinese person. The representations were based on a 7-dimensional characterization of cultural differences derived from a review of the literature. The findings suggested that cultural characterization embedded in online communication affects the social perception of others, that it can trigger stereotypes, and that it has consequences for establishing relationships. Implications for the design of social networking platforms are discussed.

Yifan Jiang, Oscar de Bruijn, Antonella De Angeli
Anchoring Design in Rural Customs of Doing and Saying

An increasing range of initiatives aim to enable rural communities in developing regions to generate their own, non-text based, digital content to share local stories, information and concerns. Video, photos and audio offer new resources for practices that give communities’ a sense of identity and continuity and that members acquire in relationships with each other, their environment and history via speech, gesture, song, music, drama, ritual, skills or crafts. However, these contexts pose challenges for designing interactions within frameworks that have a heritage of text and indirect orality and which emphasize particular communication dynamics and structures. We seek to create new design directions based on insights into local ways of ‘doing and saying’ gained in interactions with people living under traditional law and custom in the Xhosa Kingdom of Pondoland, South Africa. This paper distils themes from an ethnography when the author lived according to local norms and constraints and cogenerated design activities, situated in the community’s priorities, customary power relations and consensus-based practice. We reflect on communication in ordinary and extraordinary activities, and sociotechnical ‘experiments’ from using social networking websites to storytelling with blogs. We describe how indexicality dynamically shares context and entwines a person’s identity with physical setting; and, how practices, such as prolonged discussion, diachronic repetition and synchronous utterance, build rapport, collective memory and cohesion. We propose that these practices inspire ways that local social structures can impact on activities to design systems of organization for information sharing, with occasional reference to our observations of other rural peoples in north Mozambique and north Australia.

Nicola J. Bidwell
Faces of Privacy: Effect of Culture and Context

We repeated in Finland a study on privacy concerns originally carried out in the USA. The results suggest that there are cultural differences in the willingness of people to reveal privacy-sensitive information.

Kari-Jouko Räihä, Saila Ovaska
Fair Partnerships – Working with NGOs

This paper highlights how Non-Governmental Organizations (NGOs) can be utilized during the design of Information Communication Technologies for Development (ICT4D). We use the design process of a voter education system as a case study, which incorporated three NGOs from two African countries. Of key interest to us are the ways in which we can avoid exploiting these NGOs and make sure the ICT intervention meets their goals, as well as those of the researchers.

Shikoh Gitau, Gary Marsden

Mobile Computing 1

An Evaluation Framework for Mobile User Interfaces

We present the extensions to a software framework which supports the construction and evaluation of mixed-fidelity prototypes for mobile devices. The framework is available for desktop and mobile devices and allows designers and users to test the prototypes on actual devices. Additionally, the extensions aim at allowing designers to gather usage information, both passively and actively, tailoring the used techniques to users or project’s goals. It supports contextual and ubiquitous evaluation also including in-situ prototyping and participatory design on-the-go. We address the evaluation’s features and their contribution to the field of mobile interaction design, presenting real-life case studies and achieved results.

Marco de Sá, Luís Carriço
Exploring Cross-Device Web Use on PCs and Mobile Devices

In this paper, we explore whether sharing a user’s web browsing activity across their computing devices can make it easier to find and access web sites on a mobile device. We first surveyed 175 smartphone users about their web use across multiple devices. We found that users shared web information between devices, but generally used cumbersome manual methods to do so. In a second study, we tracked the web sites visited by 14 participants on their PC and mobile phone, and used experience-sampling surveys to determine whether sharing sites across devices would be useful. We found that participants visited many of the same sites on both their mobile device and PC, and that participants were interested in viewing additional sites from their PC on their mobile device. Our results suggest that automatically sharing web activity information between devices has potential to improve the usability of the mobile web.

Shaun K. Kane, Amy K. Karlson, Brian R. Meyers, Paul Johns, Andy Jacobs, Greg Smith
Fancy a Drink in Canary Wharf?: A User Study on Location-Based Mobile Search

We present a web-based diary study on location-based search behavior using a mobile search engine. To capture users’ location-based search behavior in a ubiquitous setting, we use a web-based diary tool that collects users’ detailed mobile search activity, their location and diary entries. This method enables us to capture users’ explicit behavior (query made), their implicit intention (motivation behind search) and the context (spatial, temporal, and social) in which the search was carried out. The results of the study show that people tend to stick closely to regularly used routes and regularly visited places, e.g. home and work. We also found that most location-based searches are conducted while in the presence of others. We summarize our findings and offer suggestions to improve location-based search by using features such as location-based service mash-ups.

Alia Amin, Sian Townsend, Jacco van Ossenbruggen, Lynda Hardman
Bringing Digital Storytelling to the Mobile

Technology has changed the way in which people tell their stories. This paper introduces digital storytelling and looks at why the mobile is an ideal platform for creating digital stories. The iterative design approach chosen for our Mobile Digital Storytelling system is discussed. Results of a final experiment, comparing our system to an existing mobile system that supports digital storytelling, are presented, which suggest that our system has met its design goals of providing an effective and efficient user interface. Qualitative insights from user evaluations show that mobile digital storytelling has a future.

Thomas Reitmaier, Gary Marsden
Exploring User Requirements for Non-visual Mobile Navigation Systems

This paper describes an explorative user study of how two different user groups experience current, as well as envisioned new mobile navigation systems. Two groups have been the primary target in this study; a group of elderly people and a group of relatively young university students that were visually impaired. The study consisted of three parts: a focus group/test, a diary study and a design workshop where the users envisioned new kinds of interaction with mobile navigation systems by building and demonstrating low-fi prototypes. Information about user requirements for these types of applications is obtained and we observe features in the study design which are relevant for a wider range of mobile services.

Charlotte Magnusson, Kirsten Rassmus-Gröhn, Konrad Tollmar, Hanna Stigmar

Mobile Computing 2

Multi-display Composition: Supporting Display Sharing for Collocated Mobile Devices

Multi-display composition is a technique that enables several mobile devices to join together over a wireless network to form a larger logical display. This logical display can be created in an

ad hoc

manner for use when and where it is needed out of a group of users’ existing mobile computers. In this work we present a multi-display composition system and discuss our implementation that supports dynamically extending the display across several devices. Furthermore, we present findings from a study of collocated groups of individuals using multi-display composition on two different types of mobile computers. We found mixed results with respect to the effect of the resulting display area. The use of two devices by a pair of participants tended to be rated more favorably than a corresponding group of four devices and participants. Furthermore, while providing additional screen real estate for smaller UMPCs, tablets were rated more favorably when using our system. Finally, we discuss usage themes that emerged from participants’ use of the multi-display composition system.

Kent Lyons, Trevor Pering, Barbara Rosario, Shivani Sud, Roy Want
Animated Transitions for Adaptive Small Size Mobile Menus

This paper explores how the user interface of a mobile device could support human perception and conception of changes in its environment. Animated transition effects may hold potential for visualizing changes in the resources available for the user through the context-aware user interface. Four different transition types are investigated. Each transition represents a different approach for visualizing changes in UI. The transitions are evaluated with 40 test subjects, half in India and half in Europe. Statistical analysis of the results indicates that animated transition effects have a clear positive effect on perception and conception of change.

Jussi Huhtala, Jani Mäntyjärvi, Aino Ahtinen, Leena Ventä, Minna Isomursu
Investigating the Use of Voice and Ink for Mobile Micronote Capture

Despite the potential benefits of digital note taking tools, research has found that people continue to use paper for creating micronotes, informal personal notes such as reminders and to-dos. Design recommendations from formative studies suggest that “natural” input modalities such as voice and digital ink could help to overcome the drawbacks of text entry on phones and PDAs. We conducted an 18-person lab study to understand the perceived and actual trade-offs that these non-traditional input methods offer for micronote capture. We found that people preferred ink (8 participants) and voice (8 participants) input over keyboard (2 participants) input. Half our participants varied the input method they used in different environments, while the rest did not. However, paper remains popular and was preferred by 8 participants when given the option. The 9 participants whose ink and voice micronotes were transcribed with higher error rates had a noticeably different experience using voice including slower capture times, and higher mental and physical demand survey responses. The percentage of participants that preferred ink, voice, and keyboard was the same for both transcription quality groups.

Adrienne H. Andrew, Amy K. Karlson, A. J. Bernheim Brush
SmartActions: Context-Aware Mobile Phone Shortcuts

Mobile phones are often regarded as difficult to use due to their size restrictions. To improve on this, in this paper we described our approach using unsupervised learning to automate common tasks on a mobile phone, thereby requiring less key presses, by means of context-dependent quick-access shortcuts presented in the homescreen of the phone. We also briefly reviewed some of our user study findings, and raised the issue of possible privacy concerns with our implementation.

Akos Vetek, John A. Flanagan, Ashley Colley, Tuomas Keränen
Can You Feel It? – Using Vibration Rhythms to Communicate Information in Mobile Contexts

Development of interfaces for interaction in mobile scenarios faces the challenge of a broad variety of different possible user contexts. New approaches are needed, which demand a minimum of attention in situations where the user is engaged in other mobility tasks. In this paper, the results of an experiment targeting the recognition of vibration rhythms in real world mobile situations are depicted, suggesting further research on tactile mobile interfaces.

Sebastian Feige

Mobile Computing 3

An Evaluation of Product Identification Techniques for Mobile Phones

Among others, consumer products can be purchased in the Internet and in traditional stores. Each of the two has dedicated advantages. An online survey conducted within the frames of this work investigates these advantages. It motivates the transition of the advantages of online shopping, such as access to recommendations of other consumers, to the sales floor. Recent trends in mobile phone technology, for example the emergence of the mobile Internet, enable exactly this transition, potentially enriching the shopping experience in the real world. A key challenge though is a fast and convenient identification of products. This work compares five product identification modalities for mobile phones in a comparative study. The dependent variables evaluated are ‘task completion time’ and ‘perceived ease of use’. Our study is the first that quantifies the advantage of automatic identification. The results indicate that automatically identifying a product scanning a tag can be up to eight times faster than entering a product name in a text field. Surprisingly, barcode recognition using a camera phone can be conducted almost as fast and convenient as scanning an RFID tag. Our work provides a benchmark for developers having to choose appropriate identification technology for their mobile application.

Felix von Reischach, Florian Michahelles, Dominique Guinard, Robert Adelmann, Elgar Fleisch, Albrecht Schmidt
Presence, Routines, and Technology Discrepancy – Information Exchange between Parents and Preschool Teachers

We have interviewed four parents and a teacher at a Swedish preschool to investigate the practices for spreading information in preschool. Our findings suggest that frequent presence in the premises of the preschool is important to get information, and that parents rely heavily on routines to make it work. When either of these points fail, breakdowns occur. Discrepancies in parents’ and teachers’ IT use also complicates the information exchange.

Stina Nylander
TimeTilt: Using Sensor-Based Gestures to Travel through Multiple Applications on a Mobile Device

We present TimeTilt, a sensor-based technique that allows multiple windows switching on mobile devices, and which overcomes the limitations of mobile devices, i.e. their impoverished input bandwidth (often no keyboard, a small tactile screen and the drawbacks of one-handed interaction). TimeTilt, which is based on a lenticular metaphor, aims at both reducing the activation time when switching between views, and supporting a natural mapping between the gestures and the navigation. We draw a brief classification of sensor-based gestures that could be used in mobile conditions, and we present an experiment.

Anne Roudaut, Mathias Baglioni, Eric Lecolinet
NFC-Based Mobile Interactions with Direct-View Displays

Two NFC-based interactions are described in the paper. The first interaction technique is referred to as Touch & Connect: a process by which an NFC tag is used to rapidly pair a mobile device with a computer. The second interaction technique is referred to as Touch & Select, and considerably extends the Touch & Connect concept by allowing the use of an NFC-enabled mobile phone to directly touch at, and select, an object on the computer screen. We achieve this by attaching a grid of NFC tags to the back of the screen. A picture browsing application has been developed in order to compare Touch & Connect and Touch & Select with the currently available Bluetooth-based approach. Our most salient findings show a considerable task time decrease for Touch-and-Connect (31%) and Touch-and-Select (43%) over the standard Bluetooth approach for picture browsing tasks.

Khoovirajsingh Seewoonauth, Enrico Rukzio, Robert Hardy, Paul Holleis

Mobile Computing 4

Design and Evaluation of an Adaptive Mobile Map-Based Visualisation System

Mobile visualisation of map-based information is a difficult task. Designers of such systems must contend with the limitations of mobile devices in terms of hardware, screen size and input mechanisms. These problems are exacerbated by the nature of spatial data, where a large information space needs to be presented and manipulated on a small screen. In this paper, a prototype adaptive mobile map-based visualisation system, called MediaMaps, is presented. MediaMaps allows users to capture, location-tag, sort and browse multimedia in a map-based view. MediaMaps was designed to adapt the information visualised, the map-based visualisations and the supporting user interface. The results of an international field study, in which participants used MediaMaps on their personal mobile phones for a three-week period, are also presented. These results show that the adaptations implemented achieved high levels of accuracy and user satisfaction and successfully addressed some of the limitations of mobile map-based visualisation.

Bradley van Tonder, Janet Wesson
Exploring Multimodal Navigation Aids for Mobile Users

When navigating in real physical environments, as human beings we tend to display systematic or near-systematic errors with distance, direction and other navigation issues. To avoid making these errors, we choose different stratategies to find our way. While there have been a lot of HCI studies of navigation design guidelines for using maps or speech-based or tactile-based guidance in mobile devices, in this paper we introduce an initial study of multimodal navigation design utilising the design practice of episodes of motion originated from urban planning. The implications of designing cues and providing rhythm, as the design guidelines of episodes of motions suggests, are explored in this study with the subjects being pedestrians with wayfinding tasks in an urban area. The main contributions of this paper are in evaluating the design implications in the context of mobile wayfinding tasks and in reflecting the results according to human wayfinding behaviour. It is concluded that by designing predictive clues and rhythm into mobile multimodal navigation applications, we can improve navigation aids for users.

Teija Vainio
Feature Use in Mobile Video Creation

Today’s mobile phones are also video cameras. People are using these ubiquitous cameras to document everyday surroundings as well as create more artistic videos. This paper examines emergent mobile film making patterns by tracking video composition and recording activities in ecologically valid contexts of use. We report the findings of a user study on user created mobile videos, where the actions of 11 active mobile video users were documented for 2 weeks. The collected material included diaries, device logs, and altogether 255 videos. Our findings characterize the features of a typical mobile video. Additionally, our study uncovers common practices, user motivations and pitfalls during filming and editing in the mobile context.

Arto Puikkonen, Jonna Häkkilä, Rafael Ballagas, Jani Mäntyjärvi
Glaze: A Visualization Framework for Mobile Devices

The processing power of mobile devices is increasing steadily; their screen size suffers more fundamental limits. Given this contrast, we identify mobile information visualization which maximizes the effectiveness of small screen displays as a key area for future development. To achieve this, we present an overview of Glaze, a plug-in based visualization framework for mobile devices based on the information visualization reference model. We discuss two prototype visualizations implemented using Glaze and designed based on the output of concept generation interviews with users.

Roberto Sousa, Valentina Nisi, Ian Oakley
A Collaborative Approach to Minimize Cellphone Interruptions

In this paper, we present a collaborative approach to minimizing inappropriate cellphone interruptions. The approach uses Bluetooth technology to discover and communicate with the surrounding cell phones in order to read their notification profiles. The profile of the majority is assumed to be the most suitable setting for the current social environment. Cellphones running the collaborative service can automatically update their profile according to the majority profile or at least alert the user to do so. We have conducted a user study to examine the acceptability and the usefulness of the collaborative service and to incorporate users’ feedback into the early design process.

Ashraf Khalil, Kay Connelly

Model-Based Design of Interactive Systems

Augmented Interactions: A Framework for Adding Expressive Power to GUI Widgets

The basic elements of WIMP interfaces have proven to be robust components for building interactive systems, but these standard interactors also have limitations. On many occasions, researchers have introduced augmented GUI elements that are capable of more expressive interactions and that are better suited to user tasks. Although many of these novel designs have been effective, augmented interactors are still invented in an ad-hoc fashion, and there is no systematic way of thinking about or designing augmentations. As a result, there is little understanding of the principles underlying augmentation, the relationships between different designs, or the possibilities for creating new interactors. In this paper we present a framework that specifies elemental interactions with WIMP components and identifies the possible ways in which augmentations can occur. We show the explanatory and generative power of the framework by analysing existing and novel augmented interactions.

Jared Cechanowicz, Carl Gutwin
Model-Based Design of Multi-device Interactive Applications Based on Web Services

Creating an interactive application based on pre-existing functionalities poses a number of novel issues in the design process. We discuss a method and an associated model-based language, which aim to address such issues in multi-device contexts. One specific aspect of this method is the ability to obtain user interfaces for accessing multiple services. In addition, the possibility to specify interactive objects, Web services accesses and scripts allows designers to describe Rich Internet Applications as well.

Fabio Paternò, Carmen Santoro, Lucio Davide Spano
Speed-Accuracy Tradeoff in Trajectory-Based Tasks with Temporal Constraint

Speed-accuracy tradeoff is a common phenomenon in many types of human motor tasks. In general, the more accurately the task is to be accomplished, the more time it takes, and vice versa. In particular, when users attempt to complete the task with a specified amount of time, the accuracy of the task can be considered as a dependent variable to measure user performance. In this paper we investigate speed-accuracy tradeoff in trajectory-based tasks with temporal constraint, through a controlled experiment that manipulates the movement time (

MT

) in addition to the tunnel amplitude (

A

) and width (

W

). A quantitative model is proposed and validated to predict the task accuracy in terms of lateral standard deviation (

SD

) of the trajectory.

Xiaolei Zhou, Xiang Cao, Xiangshi Ren
Backmatter
Metadaten
Titel
Human-Computer Interaction – INTERACT 2009
herausgegeben von
Tom Gross
Jan Gulliksen
Paula Kotzé
Lars Oestreicher
Philippe Palanque
Raquel Oliveira Prates
Marco Winckler
Copyright-Jahr
2009
Verlag
Springer Berlin Heidelberg
Electronic ISBN
978-3-642-03655-2
Print ISBN
978-3-642-03654-5
DOI
https://doi.org/10.1007/978-3-642-03655-2

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