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CHI Tables of Contents: 97-2c98-198-2a98-2b98-2c98-2d99-199-200-100-201-101-202-102-203-103-204-104-205-105-206-1

Proceedings of ACM CHI 2001 Conference on Human Factors in Computing Systems

Fullname:Proceedings of CHI 2001 Conference on Human Factors in Computing Systems
Note:Anyone, Anywhere
Editors:Michel Beaudouin-Lafon; Robert J. K. Jacob
Location:Seattle, Washington, USA
Dates:2001-Mar-31 to 2001-Apr-05
Standard No:ACM ISBN 1-58113-327-8 ACM Order Number 608013; ACM DL: Table of Contents hcibib: CHI01-1
Links:Conference Home Page
  1. Human Performance Points
  2. Designed Experiences/Experienced Designs
  3. (Trust) Worthy Web Design
  4. Motion and Emotion
  5. Designing With and For Others
  6. Heady Lessons
  7. Visions of Work
  8. Speech Studies
  9. Sensable Navigation Search
  10. On the Road
  11. Structuring Software and Systems for Learning
  12. Tangible Interfaces
  13. Focus and Context
  14. Seeing and Being Seen
  15. Home on the Range
  16. The Write Stuff
  17. Communities and Collaboration
  18. Social Interfaces
  19. 3D Navigation
  20. Social Interfaces
  21. Scenes from the Office
  22. Storytelling
  23. Information Scent
  24. Public Displays

Human Performance Points

Scale Effects in Steering Law Tasks BIBAKPDF 1-8
  Johnny Accot; Shumin Zhai
Interaction tasks on a computer screen can technically be scaled to a much larger or much smaller sized input control area by adjusting the input device's control gain or the control-display (C-D) ratio. However, human performance as a function of movement scale is not a well concluded topic. This study introduces a new task paradigm to study the scale effect in the framework of the steering law. The results confirmed a U-shaped performance-scale function and rejected straight-line or no-effect hypotheses in the literature. We found a significant scale effect in path steering performance, although its impact was less than that of the steering law's index of difficulty. We analyzed the scale effects in two plausible causes: movement joints shift and motor precision limitation. The theoretical implications of the scale effects to the validity of the steering law, and the practical implications of input device size and zooming functions are discussed in the paper.
Keywords: C-D ratio, arm, control gain, device size, elbow, finger, hand, input device, joints, limb, motor control, movement scale, steering law, wrist
Accuracy Measures for Evaluating Computer Pointing Devices BIBAKPDF 9-16
  I. Scott MacKenzie; Tatu Kauppinen; Miika Silfverberg
In view of the difficulties in evaluating computer pointing devices across different tasks within dynamic and complex systems, new performance measures are needed. This paper proposes seven new accuracy measures to elicit (sometimes subtle) differences among devices in precision pointing tasks. The measures are target re-entry, task axis crossing, movement direction change, orthogonal direction change, movement variability, movement error, and movement offset. Unlike movement time, error rate, and throughput, which are based on a single measurement per trial, the new measures capture aspects of movement behaviour during a trial. The theoretical basis and computational techniques for the measures are described, with examples given. An evaluation with four pointing devices was conducted to validate the measures. A causal relationship to pointing device efficiency (viz. throughput) was found, as was an ability to discriminate among devices in situations where differences did not otherwise appear. Implications for pointing device research are discussed.
Keywords: computer pointing devices, cursor positioning tasks, performance evaluation, performance measurement, cursor positioning tasks
Laser Pointer Interaction BIBAKPDF 17-22
  Dan R. Olsen; Travis Nielsen
Group meetings and other non-desk situations require that people be able to interact at a distance from a display surface. This paper describes a technique using a laser pointer and a camera to accomplish just such interactions. Calibration techniques are given to synchronize the display and camera coordinates. A series of interactive techniques are described for navigation and entry of numbers, times, dates, text, enumerations and lists of items. The issues of hand jitter, detection error, slow sampling and latency are discussed in each of the interactive techniques.
Keywords: camera-based interaction, group interaction, laser pointer interaction

Designed Experiences/Experienced Designs

Listen Reader: An Electronically Augmented Paper-Based Book BIBAKPDF 23-29
  Maribeth Back; Jonathan Cohen; Rich Gold; Steve Harrison; Scott Minneman
While predictions abound that electronic books will supplant traditional paper-based books, many people bemoan the coming loss of the book as cultural artifact. In this project we deliberately keep the affordances of paper books while adding electronic augmentation. The Listen Reader combines the look and feel of a real book - a beautiful binding, paper pages and printed images and text - with the rich, evocative quality of a movie soundtrack. The book's multi-layered interactive soundtrack consists of music and sound effects. Electric field sensors located in the book binding sense the proximity of the reader's hands and control audio parameters, while RFID tags embedded in each page allow fast, robust page identification.
   Three different Listen Readers were built as part of a six-month museum exhibit, with more than 350,000 visitors. This paper discusses design, implementation, and lessons learned through the iterative design process, observation, and visitor interviews.
Keywords: RFID tags, audio books, augmented books, augmented reality, electronic books, embedded tags, exhibits, gestural input, interactive audio, interactive books, interactive museum, multimodal i/o, new genres, page detection, smart documents, sound design
Exploiting Interactivity, Influence, Space and Time to Explore Non-Linear Drama in Virtual Worlds BIBAKPDF 30-37
  Mike Craven; Ian Taylor; Adam Drozd; Jim Purbrick; Chris Greenhalgh; Steve Benford; Mike Fraser; John Bowers; Kai-Mikael Jaa-Aro; Bernd Lintermann; Michael Hoch
We present four contrasting interfaces to allow multiple viewers to explore 3D recordings of dramas in on-line virtual worlds. The first is an on-line promenade performance to an audience of avatars. The second is a form of immersive cinema, with multiple simultaneous viewpoints. The third is a tabletop projection surface that allows viewers to select detailed views from a bird's-eye overview. The fourth is a linear television broadcast created by a director or editor. A comparison of these examples shows how a viewing audience can exploit four general resources - interactivity, influence, space, and time - to make sense of complex, non-linear virtual drama. These resources provide interaction designers with a general framework for defining the relationship between the audience and the 3D content.
Keywords: entertainment applications, virtual reality
Orchestrating a Mixed Reality Performance BIBAKPDF 38-45
  Boriana Koleva; Ian Taylor; Steve Benford; Mike Fraser; Chris Greenhalgh; Holger Schnadelbach; Dirk vom Lehn; Christian Heath; Ju Row-Farr; Matt Adams
A study of a professional touring mixed reality performance called Desert Rain yields insights into how performers orchestrate players' engagement in an interactive experience. Six players at a time journey through an extended physical and virtual set. Each sees a virtual world projected onto a screen made from a fine water spray. This acts as a traversable interface, supporting the illusion that performers physically pass between real and virtual worlds. Live and video-based observations of Desert Rain, coupled with interviews with players and the production team, have revealed how the performers create conditions for the willing suspension of disbelief, and how they monitor and intervene in the players experience without breaking their engagement. This involves carefully timed performances and "off-face" and "virtual" interventions. In turn, these are supported by the ability to monitor players' physical and virtual activity through asymmetric interfaces.
Keywords: mixed reality, performance, traversable interfaces

(Trust) Worthy Web Design

Cookies and Web Browser Design: Toward Realizing Informed Consent Online BIBAKPDF 46-52
  Lynette I. Millett; Batya Friedman; Edward Felten
We first provide criteria for assessing informed consent online. Then we examine how cookie technology and Web browser designs have responded to concerns about informed consent. Specifically, we document relevant design changes in Netscape Navigator and Internet Explorer over a 5-year period, starting in 1995. Our retrospective analyses leads us to conclude that while cookie technology has improved over time regarding informed consent, some startling problems remain. We specify six of these problems and offer design remedies. This work fits within the emerging field of Value-Sensitive Design.
Keywords: Internet Explorer, Netscape Navigator, Value-Sensitive Design, Web browsers, World Wide Web, computer ethics, cookies, e-business, e-commerce, ethics, human values, human-computer interaction, informed consent, interface design, locus of control, online interactions, personalization, privacy, security, social computing, social impact, tracking
Empirically Validated Web Page Design Metrics BIBAKPDF 53-60
  Melody Y. Ivory; Rashmi R. Sinha; Marti A. Hearst
A quantitative analysis of a large collection of expert-rated web sites reveals that page-level metrics can accurately predict if a site will be highly rated. The analysis also provides empirical evidence that important metrics, including page composition, page formatting, and overall page characteristics, differ among web site categories such as education, community, living, and finance. These results provide an empirical foundation for web site design guidelines and also suggest which metrics can be most important for evaluation via user studies.
Keywords: Web site design, World Wide Web, automated usability evaluation, empirical studies
What Makes Web Sites Credible?: A Report on a Large Quantitative Study BIBAKPDF 61-68
  BJ Fogg; Jonathan Marshall; Othman Laraki; Alex Osipovich; Chris Varma; Nicholas Fang; Jyoti Paul; Akshay Rangnekar; John Shon; Preeti Swani; Marissa Treinen
The credibility of web sites is becoming an increasingly important area to understand. To expand knowledge in this domain, we conducted an online study that investigated how different elements of Web sites affect people's perception of credibility. Over 1400 people participated in this study, both from the U.S. and Europe, evaluating 51 different Web site elements. The data showed which elements boost and which elements hurt perceptions of Web credibility. Through analysis we found these elements fell into one of seven factors. In order of impact, the five types of elements that increased credibility perceptions were "real-world feel", "ease of use", "expertise", "trustworthiness", and "tailoring". The two types of elements that hurt credibility were "commercial implications and "amateurism". This large-scale study lays the groundwork for further research into the elements that affect Web credibility. The results also suggest implications for designing credible Web sites.
Keywords: Web design, World Wide Web, captology, credibility, expertise, online research, trustworthiness, usability

Motion and Emotion

Improving the Performance of the Cyberlink Mental Interface with "Yes / No Program" BIBAKPDF 69-76
  Eamon Doherty; Gilbert Cockton; Chris Bloor; Dennis Benigno
We summarise the results of the first studies to investigate the Cyberlink brain body interface as an assistive technology. Three phases of studies and a contextual inquiry were performed with a range of users. A focus group was formed from brain-injured users with locked-in syndrome who have no other method of communication or control of a computer than the Cyberlink. Versions of a Yes/No program were then created to allow communication and have achieved some success with the focus group. The purpose of this paper is to discuss how this program has been improved and what steps need to be taken to create communication programs for persons with severe motor impairment. As a result of our experiences, we have been able to develop a set of design guidelines for brain-body interface operated Yes/No programs. These are presented and justified on the basis of our experiences. We also raise some general issues for assistive technologies of this nature.
Keywords: assistive technology, cyberlink, locked in syndrome, mental interface, Cyberlink
Responding to Subtle, Fleeting Changes in the User's Internal State BIBAKPDF 77-84
  Wataru Tsukahara; Nigel Ward
In human-to-human interaction, people sometimes are able to pick up and respond sensitively to the other's internal state as it shifts moment by moment over the course of an exchange. To find out whether such an ability is worthwhile for computer human interfaces, we built a semi-automated tutoring-type spoken dialog system. The system inferred information about the user's \scare{ephemeral emotions}, such as confidence, confusion, pleasure, and dependency, from the prosody of his utterances and the context. It used this information to select the most appropriate acknowledgement form at each moment. In doing so the system was following some of the basic social conventions for real-time interaction. Users rated the system with this ability more highly than a version without.
Keywords: Japanese, acknowledgements, ephemeral emotions, feedback, non-verbal, prosody, real-time, responsive, social interaction, spoken dialog, tutoring
An "Independent Visual Background" Reduced Balance Disturbance Envoked by Visual Scene Motion: Implication for Alleviating Simulator Sickness BIBAKPDF 85-89
  Henry Been-Lirn Duh; Donald E. Parker; Thomas A. Furness
Simulator sickness (SS) / virtual environment (VE) sickness is expected to become increasingly troublesome as VE technology evolves [20]. Procedures to alleviate SS / VE sickness have been of limited value [12]. This paper investigated a possible procedure to reduce SS and VE sickness. Postural disturbance was evoked by visual scene motion at different frequencies. Differences in disturbance were examined as a function of simultaneous exposure to an "independent visual background" (IVB). Eight subjects were tested at two scene motion frequencies and three different IVB conditions using a within-subjects design. An expected statistically significant interaction between IVB condition and frequency was observed. For low frequency scene movements, subjects exhibited less balance disturbance when the IVB was presented. We suggest that an IVB may alleviate disturbance when conflicting visual and inertial cues are likely to result in simulator or VE sickness.
Keywords: Computing Milieux -Computers and Society - Public Policy Issues (K.4.1): Computer-related health issues; Information Systems -Models and Principles - User/Machine Systems (H.1.2); Computing Methodologies -Computer Graphics - Three-Dimensional Graphics and Realism (I.3.7): Virtual reality; Information Systems -Information Interfaces and Presentation - Multimedia Information Systems (H.5.1): Artificial, augmented, and virtual realities; Design, Human Factors, Measurement, Management, Performance, Theory; cybersickness, self-motion perception, simulator sickness, virtual environments, virtual reality

Designing With and For Others

Layered Participatory Analysis: New Developments in the CARD Technique BIBAKPDF 90-97
  Michael J. Muller
CARD (Collaborative Analysis of Requirements and Design) is an influential technique for participatory design and participatory analysis that is in use on three continents. This paper reviews three case studies that document the development of a layered CARD approach, which distinguishes among the following: (1) observable, formal components, (2) skill and craft, and (3) interpretative description. The layered approach simplifies the CARD materials, and moves the deliberately informal technique toward a more principled analysis.
Keywords: CARD, PANDA, participatory analysis, participatory design, work analysis
Building a Human Factors "Knowledge Shelf" as a Collaborative Information Tool for Designers BIBAKPDF 98-103
  Brian H. Philips; Moin Rahman; Jari Jarvinen
Human factors professionals have long been challenged with finding an effective way of communicating critical human factors design information to product designers. The authors have created a tool called a "Knowledge Shelf" for providing human factors information to designers in a very easy to use manner. The Knowledge Shelf is an interactive virtual library of information on human factors methodologies and data relevant to the specific product development needs of designers. Available through the Motorola Intranet, the Knowledge Shelf is designed to make human factors design information easily accessible. Providing these types of information to designers positively impacts the product development process, by facilitating more user-centered design practices.
Keywords: Information Systems -Information Interfaces and Presentation - Group and Organization Interfaces (H.5.3); Information Systems -Information Interfaces and Presentation - User Interfaces (H.5.2); Information Systems -Models and Principles - User/Machine Systems (H.1.2); Computing Milieux -Management of Computing and Information Systems - Project and People Management (K.6.1): Systems analysis and design; Design, Human Factors, Management, Performance, Theory; collaborative work, engineering, industrial design, information sharing, knowledge shelf, product development
Global-Software Development Lifecycle: An Exploratory Study BIBAKPDF 104-111
  Alvin W. Yeo
This study was conducted to explore the efficacy of the global-software development lifecycle (global-SDLC), which comprises design, implementation and usability evaluation phase. A spreadsheet was adapted using the global-SDLC process to accommodate a number of cultures. The design and implementation phases were efficacious. However, in the usability evaluation phase, the usability evaluation techniques were only efficacious when participants, who were experienced computer users and participants who were familiar with the experimenter, were employed. Explanations, from cultural literature such as Hofstede, are presented and implications of these findings on the usability evaluation phase and the global-SDLC are also described.
Keywords: Hoftede's cultural dimensions, global-software development, internationalisation, localisation, usability evaluation

Heady Lessons

Ignoring Perfect Knowledge In-the-World for Imperfect Knowledge In-the-Head BIBAKPDF 112-119
  Wayne D. Gray; Wai-Tat Fu
Memory can be internal or external - knowledge in-the-world or knowledge in-the-head. Making needed information available in an interface may seem the perfect alternative to relying on imperfect memory. However, the rational analysis framework (Anderson, 1990) suggests that least-effort tradeoffs may lead to imperfect performance even when perfect knowledge in-the-world is readily available. The implications of rational analysis for interactive behavior are investigated in two experiments. In experiment 1 we varied the perceptual-motor effort of accessing knowledge in-the-world as well as the cognitive effort of retrieving items from memory. In experiment 2 we replicated one of the experiment 1 conditions to collect eye movement data. The results suggest that milliseconds matter. Least-effort tradeoffs are adopted even when the absolute difference in effort between a perceptual-motor versus a memory strategy is small, and even when adopting a memory strategy results in a higher error rate and lower performance.
Keywords: cognitive least-effort, direct-manipulation interfaces, errors, eye movements, eye tracking, interactive behavior, interface design, rational analysis, satisficing
Predicting the Effects of In-Car Interfaces on Driver Behavior using a Cognitive Architecture BIBAKPDF 120-127
  Dario D. Salvucci
When designing and evaluating in-car user interfaces for drivers, it is essential to determine what effects these interfaces may have on driver behavior and performance. This paper describes a novel approach to predicting effects of in-car interfaces by modeling behavior in a cognitive architecture. A cognitive architecture is a theoretical frame-work for building computational models of cognition and performance. The proposed approach centers on integrating a user model for the interface with an existing driver model that accounts for basic aspects of driver behavior (e.g., steering and speed control). By running the integrated model and having it interact with the interface while driving, we can generate a priori predictions of the effects of interface use on driver performance. The paper illustrates the approach by comparing four representative dialing interfaces for an in-car, hands-free cellular phone. It also presents an empirical study that validates several of the qualitative and quantitative predictions of the model.
Keywords: ACT-R, cellular phones, cognitive architectures, cognitive models, driving, in-car interfaces
Towards Demystification of Direct Manipulation: Cognitive Modeling Charts the Gulf of Execution BIBAKPDF 128-135
  David Kieras; David Meyer; James Ballas
Direct manipulation involves a large number of interacting psychological mechanisms that make the performance of a given interface hard to predict on intuitive or informal grounds. This paper applies cognitive modeling to explain the subtle effects produced by using a keypad versus a touchscreen in a performance-critical laboratory task.
Keywords: cognitive modeling, direct manipulation

Visions of Work

Visualization Components for Persistent Conversations BIBAKPDF 136-143
  Marc A. Smith; Andrew T. Fiore
An appropriately designed interface to persistent, threaded conversations could reinforce socially beneficial behavior by prominently featuring how frequently and to what degree each user exhibits such behaviors. Based on the data generated by the Netscan data-mining project [9], we have developed a set of tools for illustrating the structure of discussion threads like those found in Usenet newsgroups and the patterns of participation within the discussions. We describe the benefits and challenges of integrating these tools into a multi-faceted dashboard for navigating and reading discussions in social cyberspaces like Usenet and related interaction media. Visualizations of the structure of online discussions have applications for research into the sociology of online groups as well as possible interface designs for their members.
Keywords: Usenet, asynchronous threaded discussions, newsgroup, persistent conversation, social cybersapces, social cyberspaces, visualization
Time Aura: Interfaces for Pacing BIBAKPDF 144-151
  Lena Mamykina; Elizabeth Mynatt; Michael A. Terry
Historically one of the visions for human-computer symbiosis has been to augment human intelligence and extend people's cognitive abilities. In this paper, we present two visually-based systems to enhance a person's ability to flexibly control their pace while engaged in a cognitively demanding activity. In these investigations, we explore pacing interfaces that minimize the cognitive demands for assessing a current pace, provide ambient cues that can be quickly interpreted without incurring significant interruption from the current task, and place knowledge in the world to flexibly support different pacing strategies. Evaluation of our pacing interfaces shows that technology can successfully support pacing.
Keywords: pacing, ubiquitous computing, visual interfaces
Doom as an Interface for Process Management BIBAKPDF 152-157
  Dennis Chao
This paper explores a novel interface to a system administration task. Instead of creating an interface de novo for the task, the author modified a popular computer game, Doom, to perform useful work. The game was chosen for its appeal to the target audience of system administrators. The implementation described is not a mature application, but it illustrates important points about user interfaces and our relationship with computers. The applications relies on a computer game vernacular rather than the simulations of physical reality found in typical navigable virtual environments. Using a computer game vocabulary may broaden an application's audience by providing sn intuitive environment for children and non-technical users. In addition, the application highlights the adversarial relationships that exist in a computer and suggests a new resource allocation scheme.
Keywords: 3D user interfaces, Doom, Post-Modernism, cyberspace, first-person shooter, games, metaphors, operating systems, vernacular, video games, visualization

Speech Studies

Shall we Mix Synthetic Speech and Human Speech?: Impact on Users' Performance, Perception, and Attitude BIBAKPDF 158-165
  Li Gong; Jennifer Lai
Because it is impractical to record human voice for ever-changing dynamic content such as email messages and news, many commercial speech applications use human speech for fixed prompts and synthetic speech (TTS) for the dynamic content. However, this mixing approach may not be optimal from a consistency perspective. A 2-condition between-group experiment (N = 24) was conducted to compare two versions of a virtual-assistant interface (mixing human voice and TTS vs. TTS-only). Users interacted with the virtual assistant to manage some email and calendar tasks. Their task performance, self-perception of task performance, and attitudinal responses were measured. Users interacting with the TTS-only interface performed the task significantly better, while users interacting with the mixed-voices interface thought they did better and had more positive attitudinal responses. Explanations and design implications are suggested.
Keywords: Mixing Human Speech and Synthetic Speech, Consistency, Speech Applications, Telephone-based Solution, Virtual Assistant, Email and Calendar
Effects of Spatial Audio on Memory, Comprehension, and Preference during Desktop Conferences BIBAKPDF 166-173
  Jessica J. Baldis
An experiment was conducted to determine the effect of spatial audio on memory, focal assurance, perceived comprehension and listener preferences during desktop conferences. Nineteen participants listened to six, pre-recorded, desktop conferences. Each conference was presented using either non-spatial audio, co-located spatial audio, or scaled spatial audio, and during half of the conferences, static visual representations of the conferees were present. In the co-located condition, each conferees voice originated from directly above their image on the screen, and in the scaled spatial audio condition, the spatial separation between conferee voices was increased beyond the visual separation. Results showed that spatial audio improved all measures, increasing memory, focal assurance, and perceived comprehension. In addition, participants preferred spatial audio to non-spatial audio. No strong differences were found in the visual conditions, or between the co-located spatial condition and the scaled spatial conditions.
Keywords: 3D, audio, communication, comprehension, focal assurance, memory, perception, sound, spatial, user preference
Quiet Calls: Talking Silently on Mobile Phones BIBAKPDF 174-181
  Les Nelson; Sara Bly; Tomas Sokoler
Quiet Calls is a technology allowing mobile telephone users to respond to telephone conversations without talking aloud. QC-Hold, a Quiet Calls prototype, combines three buttons for responding to calls with a PDA/mobile phone unit to silently send pre-recorded audio directly into the phone. This permits a mixed-mode communication where callers in public settings use a quiet means of communication, and other callers experience a voice telephone call. An evaluation of QC-Hold shows that it is easily used and suggests ways in which Quiet Calls offers a new form of communication, extending the choices offered by synchronous phone calling and asynchronous voicemail.
Keywords: Computer Systems Organization -Computer System Implementation - Microcomputers (C.5.3): Portable devices (e.g., laptops, personal digital assistants); Information Systems -Information Systems Applications - Communications Applications (H.4.3); Information Systems -Information Interfaces and Presentation - User Interfaces (H.5.2); Information Systems -Models and Principles - User/Machine Systems (H.1.2); Design, Human Factors, Languages, Measurement, Management, Performance, Theory; computer mediated communication, hand-held devices, interaction design, mobile computing, telecommunication

Sensable Navigation Search

The Audio Notebook: Paper and Pen Interaction with Structured Speech BIBAKPDF 182-189
  Lisa Stifelman; Barry Arons; Chris Schmandt
This paper addresses the problem that a listener experiences when attempting to capture information presented during a lecture, meeting, or interview. Listeners must divide their attention between the talker and their notetaking activity. We propose a new device-the Audio Notebook-for taking notes and interacting with a speech recording. The Audio Notebook is a combination of a digital audio recorder and paper notebook, all in one device. Audio recordings are structured using two techniques: user structuring based on notetaking activity, and acoustic structuring based on a talker's changes in pitch, pausing, and energy. A field study showed that the interaction techniques enabled a range of usage styles, from detailed review to high speed skimming. The study motivated the addition of phrase detection and topic suggestions to improve access to the audio recordings. Through these audio interaction techniques, the Audio Notebook defines a new approach for navigation in the audio domain.
Keywords: acoustic structuring, audio, paper, pen interaction, speech, speech as data, speech interfaces, user structuring
Does Organisation by Similarity Assist Image Browsing? BIBAKPDF 190-197
  Kerry Rodden; Wojciech Basalaj; David Sinclair; Kenneth Wood
In current systems for browsing image collections, users are presented with sets of thumbnail images arranged in some default order on the screen. We are investigating whether it benefits users to have sets of thumbnails arranged according to their mutual similarity, so images that are alike are placed together. There are, of course, many possible definitions of similarity: so far we have explored measurements based on low-level visual features, and on the textual captions assigned to the images. Here we describe two experiments, both involving designers as the participants, examining whether similarity-based arrangements of the candidate images are helpful for a picture selection task. Firstly, the two types of similarity-based arrangement were informally compared. Then, an arrangement based on visual similarity was more formally compared with a control of a random arrangement. We believe this work should be of interest to anyone designing a system that involves presenting sets of images to users.
Keywords: evaluation, image retrieval, information visualisation
Using Thumbnails to Search the Web BIBAKPDF 198-205
  Allison Woodruff; Andrew Faulring; Ruth Rosenholtz; Julie Morrison; Peter Pirolli
We introduce a technique for creating novel, textually-enhanced thumbnails of Web pages. These thumbnails combine the advantages of image thumbnails and text summaries to provide consistent performance on a variety of tasks. We conducted a study in which participants used three different types of summaries (enhanced thumbnails, plain thumbnails, and text summaries) to search Web pages to find several different types of information. Participants took an average of 67, 86, and 95 seconds to find the answer with enhanced thumbnails, plain thumbnails, and text summaries, respectively. We found a strong effect of question category. For some questions, text outperformed plain thumbnails, while for other questions, plain thumbnails outperformed text. Enhanced thumbnails (which combine the features of text summaries and plain thumbnails) were more consistent than either text summaries or plain thumbnails, having for all categories the best performance or performance that was statistically indistinguishable from the best.
Keywords: Web search task, thumbnails

On the Road

On the Road and on the Web?: Comprehension of Synthetic and Human Speech While Driving BIBAKPDF 206-212
  Jennifer Lai; Karen Cheng; Paul Green; Omer Tsimhoni
In this study 24 participants drove a simulator while listening to three types of messages in both synthesized speech and recorded human speech. The messages consisted of short navigation messages, medium length (approximately 100 words) email messages, and longer news stories (approximately 200 words). After each message the participant was presented with a series of multiple choice questions to measure comprehension of the message. Driving performance was recorded. Findings show that for the low driving workload conditions in the study, (cruise control, predictable two-lane road with no intersections, invariant lead car) driving performance was not affected by listening to messages. This was true for both the synthesized speech and natural speech. Comprehension of messages in synthetic speech was significantly lower than for recorded human speech for all message types.
Keywords: comprehension, driving performance, driving simulator, speech synthesis, text-to-speech
Accordion Summarization for End-Game Browsing on PDAs and Cellular Phones BIBAKPDF 213-220
  Orkut Buyukkokten; Hector Garcia-Molina; Andreas Paepcke
We demonstrate a new browsing technique for devices with small displays such as PDAs or cellular phones. We concentrate on end-game browsing, where the user is close to or on the target page. We make browsing more efficient and easier by Accordion Summarization. In this technique the Web page is first represented as a short summary. The user can then drill down to discover relevant parts of the page. If desired, keywords can be highlighted and exposed automatically. We discuss our techniques, architecture, interface facilities, and the result of user evaluations. We measured a 57% improvement in browsing speed and 75% reduction in input effort.
Keywords: HTML, PDA (Personal Digital Assistant), WAP, WML, WWW (World-Wide Web)
ConNexus to Awarenex: Extending Awareness to Mobile Users BIBAKPDF 221-228
  John C. Tang; Nicole Yankelovich; James Begole; Max Van Kleek; Francis Li; Janak Bhalodia
We explored the use of awareness information to facilitate communication by developing a series of prototypes. The ConNexus prototype integrates awareness information, instant messaging, and other communication channels in an interface that runs on a desktop computer. The Awarenex prototype extends that functionality to wireless handheld devices, such as a Palm. A speech interface also enables callers to make use of the awareness information over the telephone. While the prototypes offer similar functionality, the interfaces reflect the different design affordances and use context of each platform. We discuss the design implications of providing awareness information on devices with varying interface and network characteristics.
Keywords: CSCW, awareness, computer-mediated communication, instant messaging, mobile devices, wireless handhelds

Structuring Software and Systems for Learning

Beyond Command Knowledge: Identifying and Teaching Strategic Knowledge for Using Complex Computer Applications BIBAKPDF 229-236
  Suresh K. Bhavnani; Frederick Reif; Bonnie E. John
Despite experience, many users do not make efficient use of complex computer applications. We argue that this is caused by a lack of strategic knowledge that is difficult to acquire just by knowing how to use commands. To address this problem, we present efficient and general strategies for using computer applications, and identify the components of strategic knowledge required to use them. We propose a framework for teaching strategic knowledge, and show how we implemented it in a course for freshman students. In a controlled study, we compared our approach to the traditional approach of just teaching commands. The results show that efficient and general strategies can in fact be taught to students of diverse backgrounds in a limited time without harming command knowledge. The experiment also pinpointed those strategies that can be automatically learned just from learning commands, and those that require more practice than we provided. These results are important to universities and companies that wish to foster more efficient use of complex computer applications.
Keywords: GOMS, instruction, strategies, training
Teachers as Simulation Programmers: Minimalist Learning and Reuse BIBAKPDF 237-244
  Mary Beth Rosson; Cheryl D. Seals
Five public school teachers were observed during two self-study sessions where they learned to use Visual AgenTalk (VAT). The first session emphasized the basic visual programming skills, while the second introduced ways to reuse existing simulations. Two versions of the reuse tutorial were developed, one offering a concrete example world for reuse, and the second an abstract world. During their learning and reuse sessions, the teachers thought out loud as they worked, enabling a detailed analysis of their goals, reactions, problems, and successes. After each session, the teachers also completed user reaction questionnaires. Although all teachers succeeded in learning the basics of VAT, they varied considerably in their reuse of the example simulations. It appears that the simplified components of the abstract world supported reuse to a greater degree than those of the concrete example world.
Keywords: simulations, teacher education, visual programming
Locus of Feedback Control in Computer-Based Tutoring: Impact on Learning Rate, Achievement and Attitudes BIBAKPDF 245-252
  Albert T. Corbett; John R. Anderson
Five public school teachers were observed during two self-study sessions where they learned to use Visual AgenTalk (VAT). The first session emphasized the basic visual programming skills, while the second introduced ways to reuse existing simulations. Two versions of the reuse tutorial were developed, one offering a concrete example world for reuse, and the second an abstract world. During their learning and reuse sessions, the teachers thought out loud as they worked, enabling a detailed analysis of their goals, reactions, problems, and successes. After each session, the teachers also completed user reaction questionnaires. Although all teachers succeeded in learning the basics of VAT, they varied considerably in their reuse of the example simulations. It appears that the simplified components of the abstract world supported reuse to a greater degree than those of the concrete example world.
Keywords: feedback in problem solving, instructional interface design, intelligent tutoring systems, student modeling

Tangible Interfaces

Sensetable: A Wireless Object Tracking Platform for Tangible User Interfaces BIBAKPDF 253-260
  James Patten; Hiroshi Ishii; Jim Hines; Gian Pangaro
In this paper we present a system that electromagnetically tracks the positions and orientations of multiple wireless objects on a tabletop display surface. The system offers two types of improvements over existing tracking approaches such as computer vision. First, the system tracks objects quickly and accurately without susceptibility to occlusion or changes in lighting conditions. Second, the tracked objects have state that can be modified by attaching physical dials and modifiers. The system can detect these changes in real-time.
   We present several new interaction techniques developed in the context of this system. Finally, we present two applications of the system: chemistry and system dynamics simulation.
Keywords: augmented reality, interactive surface, object tracking, system dynamics, tangible user interface, tangible user interface, two-handed manipulation
Surface Drawing: Creating Organic 3D Shapes with the Hand and Tangible Tools BIBAKPDF 261-268
  Steven Schkolne; Michael Pruett; Peter Schroder
Surface Drawing is a system for creating organic 3D shapes in a manner which supports the needs and interests of artists. This medium facilitates the early stages of creative design which many 3D modeling programs neglect. Much like traditional media such as line drawing and painting, Surface Drawing lets users construct shapes through repeated marking. In our case, the hand is used to mark 3D space in a semi-immersive virtual environment. The interface is completed with tangible tools to edit and manipulate models. We introduce the use of tongs to move and scale 3D shapes and demonstrate a magnet tool which is comfortably held without restricting hand motion. We evaluated our system through collaboration with artists and designers, exhibition before hundreds of users, our own extensive exploration of the medium, and an informal user study. Response was especially positive from users with an artistic background.
Keywords: 3D modeling, artistic shape creation, design prototyping, fine art, hand-based interface, repeated marking, semi-immersive environment, tangible user interface
DataTiles: A Modular Platform for Mixed Physical and Graphical Interactions BIBAKPDF 269-276
  Jun Rekimoto; Brygg Ullmer; Haruo Oba
The DataTiles system integrates the benefits of two major interaction paradigms: graphical and physical user interfaces. Tagged transparent tiles are used as modular construction units. These tiles are augmented by dynamic graphical information when they are placed on a sensor-enhanced flat panel display. They can be used independently or can be combined into more complex configurations, similar to the way language can express complex concepts through a sequence of simple words. In this paper, we discuss our design principles for mixing physical and graphical interface techniques, and describe the system architecture and example applications of the DataTiles system.
Keywords: graphical user interfaces, interaction techniques, radio-frequency identification tags, tangible user interfaces, visual language

Focus and Context

Optimizing Search by Showing Results in Context BIBAKPDF 277-284
  Susan Dumais; Edward Cutrell; Hao Chen
We developed and evaluated seven interfaces for integrating semantic category information with Web search results. List interfaces were based on the familiar ranked-listing of search results, sometimes augmented with a category name for each result. Category interfaces also showed page titles and/or category names, but re-organized the search results so that items in the same category were grouped together visually. Our user studies show that all Category interfaces were more effective than List interfaces even when lists were augmented with category names for each result. The best category performance was obtained when both category names and individual page titles were presented. Either alone is better than a list presentation, but both together provide the most effective means for allowing users to quickly examining search results. These results provide a better understanding of the perceptual and cognitive factors underlying the advantage of category groupings and provide some practical guidance to Web search interface designers.
Keywords: World Wide Web, focus-in-context, search, text categorization, usability, user interface, user study
Robust Annotation Positioning in Digital Documents BIBAKPDF 285-292
  A. J. Bernheim Brush; David Bargeron; Anoop Gupta; J. J. Cadiz
Increasingly, documents exist primarily in digital form. System designers have recently focused on making it easier to read digital documents, with annotation as an important new feature. But supporting annotation well is difficult because digital documents are frequently modified, making it challenging to correctly reposition annotations in modified versions. Few systems have addressed this issue, and even fewer have approached the problem from the users' point of view. This paper reports the results of two studies examining user expectations for robust annotation positioning in modified documents. We explore how users react to lost annotations, the relationship between types of document modifications and user expectations, and whether users pay attention to text surrounding their annotations. Our results could contribute substantially to effective digital document annotation systems.
Keywords: annotation, annotation system design, digital, documents, robust
Reading of Electronic Documents: The Usability of Linear, Fisheye, and Overview+Detail Interfaces BIBAKPDF 293-300
  Kasper Hornbaek; Erik Frokjaer
Reading of electronic documents is becoming increasingly important as more information is disseminated electronically. We present an experiment that compares the usability of a linear, a fisheye, and an overview+detail interface for electronic documents. Using these interfaces, 20 subjects wrote essays and answered questions about scientific documents. Essays written using the overview+detail interface received higher grades, while subjects using the fisheye interface read documents faster. However, subjects used more time to answer questions with the overview+detail interface. All but one subject preferred the overview+detail interface. The most common interface in practical use, the linear interface, is found to be inferior to the fisheye and overview+detail interfaces regarding most aspects of usability. We recommend using overview+detail interfaces for electronic documents, while fisheye interfaces mainly should be considered for time-critical tasks.
Keywords: electronic documents, information retrieval, information visualization, reading activity, usability, user study

Seeing and Being Seen

Eye Gaze Patterns in Conversations: There is More the Conversational Agents than Meets the Eyes BIBAKPDF 301-308
  Roel Vertegaal; Robert Slagter; Gerrit van der Veer; Anton Nijholt
In multi-agent, multi-user environments, users as well as agents should have a means of establishing who is talking to whom. In this paper, we present an experiment aimed at evaluating whether gaze directional cues of users could be used for this purpose. Using an eye tracker, we measured subject gaze at the faces of conversational partners during four-person conversations. Results indicate that when someone is listening or speaking to individuals, there is indeed a high probability that the person looked at is the person listened (p=88%) or spoken to (p=77%). We conclude that gaze is an excellent predictor of conversational attention in multiparty conversations. As such, it may form a reliable source of input for conversational systems that need to establish whom the user is speaking or listening to. We implemented our findings in FRED, a multi-agent conversational system that uses eye input to gauge which agent the user is listening or speaking to.
Keywords: attention-based interfaces, attentive agents, conversational attention, gaze, multiparty communication, tracking
The Impact of Eye Gaze on Communication using Humanoid Avatars BIBAKPDF 309-316
  Maia Garau; Mel Slater; Simon Bee; Martina Angela Sasse
In this paper we describe an experiment designed to investigate the importance of eye gaze in humanoid avatars representing people engaged in conversation. We compare responses to dyadic conversations in four mediated conditions: video, audio-only, and two avatar conditions. The avatar conditions differed only in their treatment of eye gaze. In the random-gaze condition the avatars head and eye animations were unrelated to conversational flow. In the informed-gaze condition, they were related to turn-taking during the conversation. The head animations were tracked and the eye animations were inferred from the audio stream. Our comparative analysis of 100 post-experiment questionnaires showed that the random-gaze avatar did not improve on audio-only communication. The informed-gaze avatar significantly outperformed the random-gaze model and also outperformed audio-only on several response measures. We conclude that an avatar whose gaze behaviour is related to the conversation provides a marked improvement on an avatar that merely exhibits liveliness.
Keywords: avatars, gaze, collaborative virtual environments (CVEs), computer-mediated communication (CMC), mediated communication, nonverbal behaviours
The Dynamics of Mass Online Marketplaces: A Case Study of an Online Auction BIBAKPDF 317-324
  Jungpil Hahn
The Internet has dramatically changed how people sell and buy goods. In recent years we have seen the emergence of electronic marketplaces that leverage information technology to create more efficient markets such as online auctions to bring together buyers and sellers with greater effectiveness at a massive scale. Despite the growing interest and importance of such marketplaces, our understanding of how the design of the marketplace affects buyer and seller behavior at the individual level and the market effectiveness at the aggregate level is still quite limited. This paper presents a detailed case study of a currently operational massive scale online auction marketplace. The main focus is to gain initial insights into the effects of the design of the marketplace. The results of the study point to several important considerations and implications not only for the design of online marketplaces but also for the design of large-scale websites where effective locating of information is key to user success.
Keywords: electronic marketplaces, information overload, item display, market navigation, market technostructure, massive scale online auctions, online market design

Home on the Range

Casablanca: Designing Social Communication Devices for the Home BIBAKPDF 325-332
  Debby Hindus; Scott D. Mainwaring; Nicole Leduc; Anna Elisabeth Hagstrom; Oliver Bayley
The Casablanca project explored how media space concepts could be incorporated into households and family life. This effort included prototypes built for the researchers' own home use, field studies of households, and consumer testing of design concepts. A number of previously unreported consumer preferences and concerns were uncovered and incorporated into several original prototypes, most notably ScanBoard and the Intentional Presence Lamp. Casablanca also resulted in conclusions about designing household social communication devices.
Keywords: Computer-mediated communication, CMC, domestic technologies, residential technologies, media spaces, audio spaces, shared whiteboards, awareness, ambient displays, internet appliances, design guidelines, aesthetics, consumers, homes, computer-human interaction.
Digital Family Portraits: Supporting Peace of Mind for Extended Family Members BIBAKPDF 333-340
  Elizabeth D. Mynatt; Jim Rowan; Sarah Craighill; Annie Jacobs
A growing social problem in the U.S., and elsewhere, is supporting older adults who want to continue living independently, as opposed to moving to an institutional care setting. One key part of this complex problem is providing awareness of senior adults day-to-day activities, promoting peace of mind for extended family members. In this paper, we introduce the concept of a digital family portrait that provides qualitative visualizations of a family members daily life. Leveraging a familiar household object, the picture frame, our design populates the frame with iconic imagery summarizing 28 days. In a final implementation, the digital family portrait would gather information from sensors in the home.
Keywords: aging, awareness, home, light-weight interaction, ubiquitous computing, visualization
Social Navigation of Food Recipes BIBAKPDF 341-348
  Martin Svensson; Kristina Höök; Jarmo Laaksolahti; Annika Wærn
The term Social Navigation captures every-day behaviour used to find information, people, and places - namely through watching, following, and talking to people. We discuss how to design information spaces to allow for social navigation. We applied our ideas in a recipe recommendation system. In a follow-up user study, subjects state that social navigation adds value to the service: it provides for social affordance, and it helps turning a space into a social place. The study also reveals some unresolved design issues, such as the snowball effect where more and more users follow each other down the wrong path, and privacy issues.
Keywords: awareness, online shopping, privacy, recommender system, social navigation

The Write Stuff

Chinese Input with Keyboard and Eye-Tracking: An Anatomical Study BIBAKPDF 349-356
  Jingtao Wang; Shumin Zhai; Hui Su
Chinese input presents unique challenges to the field of human computer interaction. This study provides an anatomical analysis of today's standard Chinese input process, which is based on pinyin, a phonetic spelling system in Roman characters. Through a combination of human performance modeling and experimentation, our study decomposed the Chinese input process into sub-tasks and found that choice reaction time and numeric keying, two component resulted from the large number of homophones in Chinese, were the major usability bottlenecks. Choice reaction alone took 36% of the total input time in our experiment. Numeric keying for multiple candidates selection tends to take the user's attention away from the computer visual screen. We designed and implemented the EASE (Eye Assisted Selection and Entry) system to help maintaining complete touch-typing experience without diverting visual (spacebar) and implicit eye-tracking to replace the numeric keystrokes. Our experiment showed that such a system could indeed work, even with today's imperfec teye-tracking technology.
Keywords: Chinese text input, chinese text input, eye-tracking, gaze, gaze-tracking, gaze-tracking, multi-modal interface, performance modeling, pinyin input
Model for Unistroke Writing Time BIBAKPDF 357-364
  Poika Isokoski
Unistrokes are a viable form of text input in pen-based user interfaces. However, they are a very heterogeneous group of gestures the only common feature being that all are drawn with a single stroke. Several unistroke alphabets have been proposed including the original Unistrokes, Gaffiti, Allegro, T-Cube and MDITIM. Comparing these methods usually requires a lengthy study with many writers and even then the results are biased by the earlier handwriting experience that the writers have. Therefore, a simple descriptive model for predicting the writing time for an expert user on any given unistroke alphabet thus enabling sounder argumentation on the properties of different writing methods.
Keywords: handwriting, modeling of motor performance, pen input
Text Input for Mobile Devices: Comparing Model Prediction to Actual Performance BIBAKPDF 365-371
  Christina L. James; Kelly M. Reishcel
A study was conducted to obtain performance data for entering text on a mobile phone in order to compare it to performance predictions based on two different mathematical models. Speed data was obtained for two text input methods, T9 Text Input and Multi-tap. While the direction of the results was the same for both the performance data and both model predictions (with predictive text entry being faster than Multi-tap text entry), the results for all three differed in magnitude. Suggestions for this discrepancy are provided. In addition, in order to help shape future models, additional results are presented for both input methods to show how both accuracy and speed performance varies based on user experience and text subject matter.
Keywords: keypad input, mobile phones, mobile systems, performance modeling, text entry

Communities and Collaboration

Better Home Shopping or New Democracy?: Evaluating Community Network Outcomes BIBAKPDF 372-379
  John M. Carroll; Mary Beth Rosson
This is a perspective paper on community networks - socio-technical infrastructure supporting villages, towns, and neighborhoods. Community networking is well-established, world wide, and addresses critical societal issues, such as the "crisis of community" and the sociality of the Internet. However, community network projects have not emphasized evaluation. Relatively little is known about the economic, social, and psychological consequences of community networks for the individuals, groups, and communities served. Evaluating community networks is a momentous mutual opportunity for the development of CHI evaluation methodologies and for bringing technical CHI expertise to bear on societal issues.
Keywords: community networks, evaluation, social impact
Identity Construction Environments: Supporting a Virtual Therapeutic Community of Pediatric Patients Undergoing Dialysis BIBAKPDF 380-387
  Marina U. Bers; Joseph Gonzalez-Heydrich; David Ray DeMaso
We describe a five-month pilot project conducted in the dialysis unit at Boston's Children's Hospital. Pediatric patients with renal disease used the Zora graphical multi-user environment while facing hemodialysis. Zora is an identity construction environment specifically designed to help young people explore issue of identity, while engaging in a participatory virtual community. This paper presents the experience and evaluates the feasibility and safety of using Zora in a hospital setting. It describes how Zora facilitated explorations of identity and mutual patient support and interaction. Finally it also presents design recommendations for future interventions of this kind. More generally, this paper explores the potential of technology specifically designed with therapeutic purposes to help patients cope with their illness.
Keywords: dialysis, identity, multi-user virtual environment, pediatric patients, storytelling, therapy, virtual communities
Geney: Designing a Collaborative Activity for the Palm Handheld Computer BIBAKPDF 388-395
  Arman Danesh; Kori Inkpen; Felix Lau; Keith Shu; Kellogg Booth
This paper describes a project to explore issues surrounding the development of a collaborative handheld educational application for children. A user-centered, iterative design process was used to develop Geney, a collaborative problem solving application to help children explore genetic concepts using Palm handheld computers. The design methodology utilized mock-ups of representative tasks and scenarios, pre-design meetings with targets users, prototype development, and feedback sessions with target users. The results of this work identify an effective way of utilizing handheld computers for collaborative learning and provide important insights into the design of handheld applications for children. This work also illustrates the necessity of user-centered design when new user groups are targeted, especially when novel user interface paradigms are employed that go beyond current windows-based interfaces.
Keywords: CSCL, CSCW, PDAs, children

Social Interfaces

Relational Agents: A Model and Implementation of Building User Trust BIBAKPDF 396-403
  Timothy Bickmore; Justine Cassell
Building trust with users is crucial in a wide range of applications, such as financial transactions, and some minimal degree of trust is required in all applications to even initiate and maintain an interaction with a user. Humans use a variety of relational conversational strategies, including small talk, to establish trusting relationships with each other. We argue that such strategies can also be used by interface agents, and that embodied conversational agents are ideally suited for this task given the myriad cues available to them for signaling trustworthiness. We describe a model of social dialogue, an implementation in an embodied conversation agent, and an experiment in which social dialogue was demonstrated to have an effect on trust, for users with a disposition to be extroverts.
Keywords: embodied conversational agent, natural language, personality, small talk, social interface, trust
An Empirical Study of Human Web Assistants: Implications for User Support in Web Information Systems BIBAKPDF 404-411
  Johan Aberg; Nahid Shahmehri
User support is an important element in reaching the goal of universal usability for Web information systems. Recent developments indicate that human involvement in user support is a step towards this goal. However, most such efforts are currently being pursued on a purely intuitive basis. This, empirical findings about the role of human assistants are important. In this paper we present the findings from a field study of a general user support model for Web information systems. We show that integrating human assistance into Web systems is a way to provide efficient user support. Further, this integration makes a Web site more fun to use and increases the user's trust in the site. The support also improves the site atmosphere. Our findings are summarised as recommendations and design guidelines for decision-makers and developers Web systems.
Keywords: Web information systems, attitude, design guidelines, efficiency, field study, universal usability, user support
Social Presence in Web Surveys BIBAKPDF 412-417
  Mick P. Couper; Roger Tourangeau; Darby M. Steiger
Social interface theory has widespread influence in the field of human-computer interaction. The basic thesis is that humanizing cues in a computer interface can engender responses from users similar to human-human interaction. In contrast, the survey interviewing literature suggests that computer administration of surveys on highly sensitive topics reduces or eliminates social desirability effect, even when such humanizing features as voice are used.
   In attempting to reconcile these apparently contradictory findings, we varied features of the interface in a Web survey
Keywords: Web surveys, social desirability, social interfaces

3D Navigation

Exploring 3D Navigation: Combining Speed-COupled Flying with Orbiting BIBAKPDF 418-425
  Desney S. Tan; George G. Robertson; Mary Czerwinski
We present a task-based taxonomy of navigation techniques for 3D virtual environments, used to categorize existing techniques, drive exploration of the design space, and inspire new techniques. We briefly discuss several new techniques, and describe in detail one new techniques, Speed-coupled Flying with Orbiting. This technique couples control of movement speed to camera height and tilt, allowing users to seamlessly transition between local environment-views and global overviews. Users can also orbit specific objects for inspection. Results from two competitive user studies suggest users performed better with Speed-coupled Flying with Orbiting over alternatives, with performance also enhanced by a large display.
Keywords: 3D virtual environments, egocentric navigation, interaction techniques, user studies

Social Interfaces

Reaching Movements to Augmented and Graphic Objects in Virtual Environments BIBAKPDF 426-433
  Andrea H. Mason; Masuma A. Walji; Elaine J. Lee; Christine L. MacKenzie
This work explores how the availability of visual and haptic feedback affects and kinematics of reaching performance in a tabletop virtual environment. Eight subjects performed reach-to-grasp movements toward target objects of various sites in conditions where visual and haptic feedback were either present or absent. It was found that movement time was slower when visual feedback of the moving limb was not available. Further MT varied systematically with target size when haptic feedback was available (i.e. augmented targets), and thus followed Fitts' law. However, movement times were constant regardless of target size when haptic feedback was removed. In depth analysis of the reaching kinematics revealed that subjects spent longer decelerating toward smaller targets in conditions where haptic feedback was available. In contrast, deceleration time was constant when haptic feedback was absent. These results suggest that visual feedback about the moving limb and veridical haptic feedback about object contract are extremely important for humans to effectively work in virtual environments.
Keywords: Fitts' law, augmented reality, empirical data, haptic feedback, human performance, interaction, interaction, kinematic data, object manipulation, sensory information, sensory manipulation, visual feedback
3D or Not 3D?: Evaluating the Effect of the Third Dimension in a Document Management System BIBAKPDF 434-441
  Andy Cockburn; Bruce McKenzie
Several recent research systems have provided interactive three-dimensional (3D) visualisations for supporting everyday work such as file and document management. But what improvements do these 3D interfaces offer over their traditional 2D counterparts? This paper describes the comparative evaluation of two document management systems that differ only in the number of dimensions used for displaying and interacting with the data. The 3D system is heavily based on Robertson et al.'s Data Mountain, which supports users in storing, organising and retrieving 'thumbnail' representations of documents such as bookmarked Web-pages. Results show that our subjects were faster at storing and retrieving pages in the display when using the 2D interface, but not significantly so. As expected, retrieval times significantly increased as the number of thumbnails increased. Despite the lack of significant differences between the 2D and 3D interfaces, subjective assessments showed a significant preference for the 3D interface.
Keywords: 3D user interfaces, document management, information visualisation, spatial memory

Scenes from the Office

Automating Camera Management for Lecture Room Environments BIBAKPDF 442-449
  Qiong Liu; Yong Rui; Anoop Gupta; J. J. Cadiz
Given rapid improvements in network infrastructure and streaming-media technologies, a large number of corporations and universities are recording lectures and making them available online for anytime, anywhere access. However, producing high-quality lecture videos is still labor intensive and expensive. Fortunately, recent technology advances are making it feasible to build automated camera management systems to capture lectures. In this paper we report on our design, implementation and study of such a system. Compared to previous work-which has tended to be technology centric-we started with interviews with professional video producers and used their knowledge and expertise the create video production rules. We then targeted technology components that allowed us to implement a substantial portion of these rules, including the design of a virtual video director. The system's performance was compared to that of a human operator via a user study. Results suggest that our system's quality in close to that of a human-controlled system. In fat most remote audience members could not tell if the video was produced by a computer or a person.
Keywords: automated camera management, sound source localization, speaker tracking, video production rules, virtual video director
Viewing Meeting Captured by an Omni-Directional Camera BIBAKPDF 450-457
  Yong Rui; Anoop Gupta; J. J. Cadiz
One vision of future technology is the ability to easily and inexpensively capture any group meeting that occurs, store it, and make it available for people to view anytime and anywhere on the network. One barrier to achieving this vision has been the design of low-cost camera systems that can capture important aspects of the meeting without needing a human camera operator. A promising solution that has emerged recently is omni-directional cameras that can capture a 360-degree video of the entire meeting.
   The panoramic capability provided by these cameras raises both new opportunities and new issues for the interfaces provided for post-meeting viewers -- for example, do we show all meeting participants all the time or do we just show the person who is speaking, how much control do we provide to the end-user in selecting the view, and will providing this control distract them from their task. These are not just user interface issues, they also raise tradeoffs for the client-server systems used to deliver such content. They impact how much data needs to be stored on the disk, what computation can be done on the server vs. the client, and how much bandwidth is needed. We report on a prototype system built using an omni-directional camera and results from user studies of interface preferences expressed by viewers.
Keywords: omni-directional camera systems, on-demand meeting watching
Partitioning Digital Worlds: Focal and Peripheral Awareness in Multiple Monitor Use BIBAKPDF 458-465
  Jonathan Grudin
Software today does not help us partition our digital worlds effectively. We must organize them ourselves. This field study of users of multiple monitors examines how people with a lot of display space arrange information. Second monitors are generally used for secondary activities related to principal tasks, for peripheral awareness of information that is not the main focus, and for easy access to resources. A second monitor improves efficiency in ways that are difficult to measure yet can have substantial subjective benefit. The study concludes with illustrations of shortcomings of today's systems and applications: the way we work could be improved at relatively low cost.
Keywords: awareness, displays, multiple monitors


Folk Computing: Revisiting Oral Tradition as a Scaffold for Co-Present Communities BIBAKPDF 466-473
  Rick Borovoy; Brian Silverman; Tim Gorton; Matt Notowidigdo; Brian Knep; Mitchel Resnick; Jeff Klann
In this paper, we introduce Folk Computing: an approach for using technology to support co-present community building inspired by the concept of folklore. We also introduce a new technology, called "i-balls," whose design helped fashion this approach. The design of the i-ball environment is explained in terms of our effort to simultaneously preserve what works about folklore while also using technology to expand its power as a medium for community building.
Keywords: PDA, community, education, face-to-face, folklore, groupware, handheld, mobile computing, social computing, ubiquitous computing
Designing Palaver Tree Online: Supporting Social Roles in a Community of Oral History BIBAKPDF 474-481
  Jason B. Ellis; Amy S. Bruckman
As a more diverse population of users moves online, understanding how to help those groups work together and leverage their diverse skills poses a significant challenge for human-computer interaction. This paper presents a case study of the design of an online community that supports kids interviewing elders to build up a shared database of oral history. Two pilot studies with existing technology are presented, and a software design based on those studies is described, along with future work. This work shows the value of prototyping with existing technology in order to uncover user needs in an onine environment.
Keywords: CSCL, children, online community, user-centered design
Classroom Collaboration in the Design of Tangible Interfaces for Storytelling BIBAKPDF 482-489
  Danae Stanton; Victor Bayon; Helen Neale; Ahmed Ghali; Steve Benford; Sue Cobb; Rob Ingram; John Wilson; Tony Pridmore; Claire O'Malley
We describe the design of tangible interfaces to the KidPad collaborative drawing tool. Our aims are to support the re-enactment of stories to audiences, and integration within real classroom environments. A six-month iterative design process, working with children and teachers in school, has produced the "magic carpet", an interface that uses pressure mats and video-tracked and barcoded physical props to navigate a story in KidPad. Reflecting on this process, we propose four guidelines for the design of tangible interfaces for the classroom. (1) Use physical size and physical props to encourage collaboration. (2) Be aware of how different interfaces emphasize different actions. (3) Be aware that superficial changes to the design can produce very different physical interactions. (4) Focus on open low-tech technologies rather than (over) polished products.
Keywords: children, participatory design, storytelling, tangibles

Information Scent

Using Information Scent to Model User Information Needs and Actions and the Web BIBAKPDF 490-497
  Ed H. Chi; Peter Pirolli; Kim Chen; James Pitkow
On the Web, users typically forage for information by navigating from page to page along Web links. Their surfing patterns or actions are guided by their information needs. Researchers need tools to explore the complex interactions between user needs, user actions, and the structures and contents of the Web. In this paper, we describe two computational methods for understanding the relationship between user needs and user actions. First, for a particular pattern of surfing, we seek to infer the associated information need. Second, given an information need, and some pages as starting pints, we attempt to predict the expected surfing patterns. The algorithms use a concept called "information scent", which is the subjective sense of value and cost of accessing a page based on perceptual cues. We present an empirical evaluation of these two algorithms, and show their effectiveness.
Keywords: World Wide Web, data mining, information foraging, information retrieval, information scent, usability
Information Scent as a Driver of Web Behavior Graphs: Results of a Protocol Analysis Method for Web Usability BIBAKPDF 498-505
  Stuart K. Card; Peter Pirolli; Mija Van Der Wege; Julie B. Morrison; Robert W. Reeder; Pamela K. Schraedley; Jenea Boshart
The purpose of this paper is to introduce a replicable WWW protocol analysis methodology illustrated by application to data collected in the laboratory. The methodology uses instrumentation to obtain detailed recordings of user actions with a browser, caches Web pages encountered, and videotapes talk-aloud protocols. We apply the current form of the method to the analysis of eight Web protocols, visualizing the structure of the interaction and showing the strong effect of information scent in determining the path followed.
Keywords: Web behavior graph, Web usability, Weblogger, behavior graph, information foraging, information scent, protocol analysis, web-eyemapper
Visual Information Foraging in a Focus + Context Visualization BIBAKPDF 506-513
  Peter Pirolli; Stuart K. Card; Mija M. Van Der Wege
Eye tracking studies of the Hyperbolic Tree browser [10] suggest that visual search in focus+context displays is highly affected by information scent (i.e., local cues, such as text summaries, used to assess and navigate toward distal information sources). When users detected a strong information scent, they were able to reach their goal faster with the Hyperbolic Tree browser than with a conventional browser. When users detected a weak scent or no scent, users exhibited less efficient search of areas with a high density of visual items. In order to interpret these results we present an integration of the CODE Theory of Visual Attention (CTVA) with information foraging theory. Development of the CTVA-foraging theory could lead to deeper analysis of interaction with visual displays of content, such as the World Wide Web or information visualizations.
Keywords: CODE theory of visual attention, focus+context, hyperbolic tree, information foraging, information scent, information visualization, visual attention, visual search

Public Displays

The Notification Collage: Posting Information to Public and Personal Displays BIBAKPDF 514-521
  Saul Greenberg; Michael Rounding
The Notification Collage (NC) is a groupware system where distributed and co-located colleagues comprising a small community post media elements onto a real-time collaborative surface that all members can see. Akin to collages of information found on public bulletin boards, NC randomly places incoming elements onto this surface. People can post assorted media: live video from desktop cameras; editable sticky notes; activity indicator; slide shows displaying a series of digital photos, snapshots of a person's digital desktop, and Web page thumbnails. User experiences show that NC becomes a rich resource for awareness and collaboration. Community members indicate their presence to others by posting live video. They regularly act on this information by engaging in text and video conversations. Because all people can overhear conversations, these become active opportunities to join in. People also post items they believe will be interesting to others, such as desktop snapshots and vacation photos. Finally, people use NC somewhat differently when it is displayed on a large public screen than when it appears on a personal computer.
Keywords: awareness, informal interaction, media spaces, messaging
Single Display Privacyware: Augmenting Public Displays with Private Information BIBAKPDF 522-529
  Garth B. D. Shoemaker; Kori Inkpen
The research area of Single Display Groupware (SDG) confronts the standard model of computing interaction, one user working on one computer, by investigating how the best support groups of users interacting with a shared display. One problem that has arisen in SDG research concerns access to private information. Previously, private information could not be displayed on a shared display, it could only be accessed on external devices, such as private monitors or Personal Digital Assistants (PDAs). This paper discusses Single Display Privacyware (SDP), an interaction technique that allows private information to be shown within the context of a shared display. A description of the hardware and software components of our prototype SDP system is given, as are the results of a user study performed to investigate users interacting in the environment. Conclusions concerning future research in the area of SDP are discussed.
Keywords: CSCW, awareness, collaboration, privacy, single display groupware, single display privacyware (SDP)
Linking Public Spaces: Technical and Social Issues BIBAKPDF 530-537
  Gavin Jancke; Gina Danielle Venolia; Jonathan Grudin; J. J. Cadiz; Anoop Gupta
Three public spaces frequency used by members of a single organization who are distributed across different floors of two buildings were linked by constantly-running video and audio connections. We discuss the design of the system, including issues in providing low-latency, full-duplex audio-video connectivity, ways to increase possibilities for interaction while addressing privacy concerns, and the introduction of the system to the community. We report on responses to the system and lessons learned, including unexpected issues, such as creative decorations of the spaces and assertions by a vocal minority of employees about the private nature of "public space."
Keywords: informal communication, privacy, videoconferencing