HCI Bibliography Home | HCI Conferences | CHI Archive | Detailed Records | RefWorks | EndNote | Hide Abstracts
CHI Tables of Contents: 96-2c97-197-2a97-2b97-2c98-198-2a98-2b98-2c98-2d99-199-200-100-201-101-202-102-203-103-204-1

Proceedings of ACM CHI 99 Conference on Human Factors in Computing Systems

Fullname:Proceedings of CHI 99 Conference on Human Factors in Computing Systems
Note:The CHI is the Limit
Editors:Marian G. Williams; Mark W. Altom; Kate Ehrlich; William Newman; Steven Pemberton
Location:Pittsburgh, Pennsylvania
Dates:1999-May-15 to 1999-May-20
Volume:1
Publisher:ACM
Standard No:ACM ISBN 1-58113-076-7 ACM Order Number 608991 Addison-Wesley ISBN 0-201-48559-1; ACM DL: Table of Contents hcibib: CHI99-1
Papers:78
Pages:629
Links:Conference Home Page
  1. CHI 1999-05-15 Volume 1
    1. Groupware
    2. Alternatives to QWERTY
    3. Object Manipulation Studies in Virtual Environments
    4. Social Foundations and Impacts of HCI
    5. Wearable and Tangible Audio
    6. Collaborative and Multimedia Systems
    7. Characters and Agents
    8. Progress in Drawing and CAD
    9. Programming Techniques and Issues
    10. Touching, Pointing, and Choosing
    11. Gaze and Purpose
    12. Foundations for Navigation
    13. Working with People Near and Far
    14. Stories and Narratives
    15. Video: Stories and Narratives
    16. Profiles, Notes, and Surfaces
    17. Tagging and Tracking Objects in Physical UIs
    18. Augmented Surfaces
    19. Cognitive Models of Screen Interaction
    20. Tools for Building Interfaces and Applications
    21. Vision and Fitts' Law
    22. Learning and Reading
    23. Navigation and Visualization
    24. Virtual Reality and Embodiment
    25. Organizing Information on the Web
    26. Speech and Multimodal Interfaces
    27. Advances in User Participation

CHI 1999-05-15 Volume 1

Groupware

An Empirical Study of How People Establish Interaction: Implications for CSCW Session Management Models BIBAKPDF 1-8
  Steinar Kristoffersen; Fredrik Ljungberg
In this paper, we report the results of an empirical study of how people, as part of their daily work activities, go about to establish collaboration. We examine the empirical findings and relate them to existing research on CSCW session management models, i.e., the mechanisms in CSCW systems that define the way in which people can join together in collaboration. Existing models leave a lot to be desired, in particular because they tend to assume that indexical elements of interaction management are substitutable by objective representation of artifacts. Based on the empirical findings, we derive three principles to consider in the design of CSCW session management models.
Keywords: Session management, Field study, Ethnography, Design implications
Chat Circles BIBAKPDF 9-16
  Fernanda B. Viegas; Judith S. Donath
Although current online chat environments provide new opportunities for communication, they are quite constrained in their ability to convey many important pieces of social information, ranging from the number of participants in a conversation to the subtle nuances of expression that enrich face to face speech. In this paper we present Chat Circles, an abstract graphical interface for synchronous conversation. Here, presence and activity are made manifest by changes in color and form, proximity-based filtering intuitively breaks large groups into conversational clusters, and the archives of a conversation are made visible through an integrated history interface. Our goal in this work is to create a richer environment for online discussions.
Keywords: Chatroom, Conversation, Social visualization, Turn-taking, Graphical history, Internet, World Wide Web
Social, Individual & Technological Issues for Groupware Calendar Systems BIBAKPDF 17-24
  Leysia Palen
Designing and deploying groupware is difficult. Groupware evaluation and design are often approached from a single perspective, with a technologically-, individually-, or socially-centered focus. A study of Groupware Calendar Systems (GCSs) highlights the need for a synthesis of these multiple perspectives to fully understand the adoption challenges these systems face. First, GCSs often replace existing calendar artifacts, which can impact users' calendaring habits and in turn influence technology adoption decisions. Second, electronic calendars have the potential to easily share contextualized information publicly over the computer network, creating opportunities for peer judgment about time allocation and raising concerns about privacy regulation. However, this situation may also support coordination by allowing others to make useful inferences about one's schedule. Third, the technology and the social environment are in a reciprocal, co-evolutionary relationship: the use context is affected by the constraints and affordances of the technology, and the technology also co-adapts to the environment in important ways. Finally, GCSs, despite being below the horizon of everyday notice, can affect the nature of temporal coordination beyond the expected meeting scheduling practice.
Keywords: Groupware calendar systems, Ethnography, CSCW, Calendars, Diaries, Time, Sociotemporality, Meeting scheduling

Alternatives to QWERTY

The Design and Evaluation of a High-Performance Soft Keyboard BIBAKPDF 25-31
  I. Scott MacKenzie; Shawn X. Zhang
The design and evaluation of a high performance soft keyboard for mobile systems are described. Using a model to predict the upper-bound text entry rate for soft keyboards, we designed a keyboard layout with a predicted upper-bound entry rate of 58.2 wpm. This is about 35% faster than the predicted rate for a QWERTY layout. We compared our design ("OPTI") with a QWERTY layout in a longitudinal evaluation using five participants and 20 45-minute sessions of text entry. Average entry rates for OPTI increased from 17.0 wpm initially to 44.3 wpm at session 20. The average rates exceeded those for the QWERTY layout after the 10th session (about 4 hours of practice). A regression equation (R² = .997) in the form of the power-law of learning predicts that our upper-bound prediction would be reach at about session 50.
Keywords: Soft keyboards, Mobile systems, Stylus input, Pen input, Linguistic models, Fitts' law, Digraph probabilities
Non-Keyboard QWERTY Touch Typing: A Portable Input Interface for the Mobile User BIBAKPDF 32-39
  Mikael Goldstein; Robert Book; Gunilla Alsio; Silvia Tessa
Using traditional mobile input devices results in decreased effectiveness and efficiency. To improve usability issues a portable Non-Keyboard QWERTY touch-typing paradigm that supports the mobile touch-typing user is presented and investigated. It requires negligible training time. Pressure sensors strapped to the fingertips of gloves detect which finger is depressed. A language model based on lexical and syntactic knowledge transforms the depressed finger stroke sequence into real words and sentences. Different mobile input QWERTY paradigms (miniaturised, floating and Non-Keyboard) have been compared with full-size QWERTY. Among the mobile input paradigms, the Non-Keyboard fared significantly better, both regarding character error rate and subjective ratings.
Keywords: Mobile user, QWERTY, Keyboard, Touch-typing, Text input, Stylus input, PDA, Portability, Wizard-of-Oz, Language model, Lexical knowledge, Syntactic knowledge
Implications for a Gesture Design Tool BIBAKPDF 40-47
  Allan Christian, Jr. Long; James A. Landay; Lawrence A. Rowe
Interest in pen-based user interfaces is growing rapidly. One potentially useful feature of pen-based user interfaces is gestures, that is, a mark or stroke that causes a command to execute. Unfortunately, it is difficult to design gestures that are easy 1) for computers to recognize and 2) for humans to learn and remember. To investigate these problems, we built a prototype tool typical of those used for designing gesture sets. An experiment was then performed to gain insight into the gesture design process and to evaluate this style of tool. The experiment confirmed that gesture design is very difficult and suggested several ways in which current tools can be improved. The most important improvement is to make the tools more active and provide more guidance for designers. This paper describes the gesture design tool, the experiment, and its results.
Keywords: Pen-based user interface, PDA, User study, Gesture, UI design

Object Manipulation Studies in Virtual Environments

Object Manipulation in Virtual Environments: Relative Size Matters BIBAKPDF 48-55
  Yanclin Wang; Christine L. MacKenzie
An experiment was conducted to systematically investigate combined effects of controller, cursor and target size on multidimensional object manipulation in a virtual environment. It was found that it was the relative size of controller, cursor and target that significantly affected object transportation and orientation processes. There were significant interactions between controller size and cursor size as well as between cursor size and target size on the total task completion time, transportation time, orientation time and spatial errors. The same size of controller and cursor improved object manipulation speed, and the same size of cursor and target generally facilitated object manipulation accuracy, regardless of their absolute sizes. Implications of these findings for human-computer interaction design are discussed.
Keywords: Size effect, Human performance, Virtual reality, User interfaces, Input device, Graphic design, 3D, Docking, Controls and displays, Fitts' law
Exploring Bimanual Camera Control and Object Manipulation in 3D Graphics Interfaces BIBAKPDF 56-63
  Ravin Balakrishnan; Gordon Kurtenbach
We explore the use of the non-dominant hand to control a virtual camera while the dominant hand performs other tasks in a virtual 3D scene. Two experiments and an informal study are presented which evaluate this interaction style by comparing it to the status-quo unimanual interaction. In the first experiment, we find that for a target selection task, performance using the bimanual technique was 20% faster. Experiment 2 compared performance in a more complicated object docking task. Performance advantages are shown, however, only after practice. Free-form 3D painting was explored in the user study. In both experiments and in the user study participants strongly preferred the bimanual technique. The results also indicate that user preferences concerning bimanual interaction may be driven by factors other than simple time-motion performance advantages.
Keywords: Bimanual input, 3D interfaces, Camera control, Interaction techniques, Empirical evaluation
Towards Usable VR: An Empirical Study of User Interfaces for Immersive Virtual Environments BIBAKPDF 64-71
  Robert W. Lindeman; John L. Sibert; James K. Hahn
This paper reports empirical results from a study into the use of 2D widgets in 3D immersive virtual environments. Several researchers have proposed the use of 2D interaction techniques in 3D environments, however little empirical work has been done to test the usability of such approaches. We present the results of two experiments conducted on low-level 2D manipulation tasks within an immersive virtual environment. We empirically show that the addition of passive-haptic feedback for use in precise UI manipulation tasks can significantly increase user performance. Furthermore, users prefer interfaces that provide a physical surface, and that allow them to work with interface widgets in the same visual field of view as the objects they are modifying.
Keywords: 3D user interfaces, Bimanual interaction, Virtual environments, Virtual reality, Passive-haptic feedback

Social Foundations and Impacts of HCI

Socially Translucent Systems: Social Proxies, Persistent Conversation, and the Design of "Babble" BIBAKPDF 72-79
  Thomas Erickson; David N. Smith; Wendy A. Kellogg; Mark Laff; John T. Richards; Erin Bradner
We take as our premise that it is possible and desirable to design systems that support social processes. We describe Loops, a project which takes this approach to supporting computer-mediated communication (CMC) through structural and interactive properties such as persistence and a minimalist graphical representation of users and their activities that we call a social proxy. We discuss a prototype called "Babble" that has been used by our group for over a year, and has been deployed to six other groups at the Watson labs for about two months. We describe usage experiences, lessons learned, and next steps.
Keywords: Conversation, Discourse, Awareness, Social activity, Computer-mediated communication, CMC, IRC, Chat, CSCW, Social computing, Design, Visualization
The Elements of Computer Credibility BIBAKPDF 80-87
  BJ Fogg; Hsiang Tseng
Given the importance of credibility in computing products, the research on computer credibility is relatively small. To enhance knowledge about computers and credibility, we define key terms relating to computer credibility, synthesize the literature in this domain, and propose three new conceptual frameworks for better understanding the elements of computer credibility. To promote further research, we then offer two perspectives on what computer users evaluate when assessing credibility. We conclude by presenting a set of credibility-related terms that can serve in future research and evaluation endeavors.
Keywords: Credibility, Trustworthiness, Expertise, Persuasion, Captology, Trust, Influence, Information quality, Psychology of HCI
A Better Mythology for System Design BIBAKPDF 88-95
  Jed Harris; Austin Henderson
The past decades have seen huge improvements in computer systems but these have proved difficult to translate into comparable improvements in the usability and social integration) of computers. We believe that the problem is a deeply rooted set of assumptions about how computer systems should be designed, and about who should be doing that design.
   Human organizations are continually evolving to meet changing circumstances of resource and need. In contrast, computers are quite rigid, incapable of adaptation on their own. Therefore when computer systems are incorporated into human organizations, those organizations must adapt the computers to changing circumstances. This adaptation is another human activity that technology should support, but our design philosophies are oddly silent about it.
   This paper explores the origins of these problems in the norms developed for managing human organizations, proposes partial solutions that can be implemented with current systems technology, and speculates about the long-term potential for radical improvements in system design.
Keywords: System evolution, Accommodation, Mythology, Pliant systems

Wearable and Tangible Audio

Nomadic Radio: Scaleable and Contextual Notification for Wearable Audio Messaging BIBAKPDF 96-103
  Nitin Sawhney; Chris Schmandt
Mobile workers need seamless access to communication and information services on portable devices. However current solutions overwhelm users with intrusive and ambiguous notifications. In this paper, we describe scaleable auditory techniques and a contextual notification model for providing timely information, while minimizing interruptions. User's actions influence local adaptation in the model. These techniques are demonstrated in Nomadic Radio, an audio-only wearable computing platform.
Keywords: Auditory I/O, Passive awareness, Wearable computing, Adaptive interfaces, Interruptions, Notifications
Tangible Progress: Less is More in Somewire Audio Spaces BIBAKPDF 104-111
  Andrew Singer; Debby Hindus; Lisa Stifelman; Sean White
We developed four widely different interfaces for users of Somewire, a prototype audio-only media space. We informally studied users' experiences with the two screen-based interfaces. We prototyped a non-screen-based interface as an example of a novel tangible interface for a communication system. We explored the conflict between privacy and simplicity of representation, and identified two unresolved topics: the role of audio quality and the prospects for scaling audio spaces beyond a single workgroup. Finally, we formulated a set of design guidelines for control and representation in audio spaces, as follows: GUIs are not well-suited to audio spaces, users do not require control over localization or other audio attributes, and awareness of other users' presence is desirable.
Keywords: Audio, Speech interactions, Mediated communication, Computer-mediated communication, CMC, User interfaces, Representations, Media space, Audio space, Audio-only, Tangible interactions, Active objects, Design guidelines
Whisper: A Wristwatch Style Wearable Handset BIBAKPDF 112-119
  Masaaki Fukumoto; Yoshinobu Tonomura
"Whisper" is a new wrist-worn handset, which is used by inserting the fingertip into the ear canal. A received signal is conveyed from a wrist-mounted actuator to the ear canal via the hand and a finger by bone conduction. The user's voice is captured by a microphone mounted on the inside of the wrist. All components of Whisper can be mounted on the wrist, and usability does not decrease if the size of components is miniaturized. So, both wearability and usability can be achieved together. The way Whisper is operated is similar to that of an ordinary telephone handset. Thus, onlookers may not look upon Whisper's operation as "talking to oneself", even if the associated PDA is controlled by voice commands. Whisper is especially effective in a noisy environment. Signals received via bone conduction can be heard clearly in the presence of noise without raising the volume (-12 dB at noise = 90 dB(A) in comparison to cellular phone handset). Whisper is also effective in avoiding the annoying problem of the user's voice being raised in a noisy situation. Feedback of the user's utterance is boosted by bone conduction when covering the ear canal with a fingertip, then the user's voice does not need to raised in the presence of noise (-6 dB at noise = 90 dB(A) in comparison to cellular phone handset). Whisper is useful as a voice interface for a wrist-worn PDA and cellular phone.
Keywords: Handset, Wearable computer, PDA, Cellular phone, Interface device, Whisper, UbiButton

Collaborative and Multimedia Systems

i-LAND: An Interactive Landscape for Creativity and Innovation BIBAKPDF 120-127
  Norbert A. Streitz; Jorg Geissler; Torsten Holmer; Shin'ichi Konomi; Christian Muller-Tomfelde; Wolfgang Reischl; Petra Rexroth; Peter Seitz; Ralf Steinmetz
We describe the i-LAND environment which constitutes an example of our vision of the workspaces of the future, in this case supporting cooperative work of dynamic teams with changing needs. i-LAND requires and provides new forms of human-computer interaction and new forms of computer-supported cooperative work. Its design is based on an integration of information and architectural spaces, implications of new work practices and an empirical requirements study informing our design. i-LAND consists of several 'roomware' components, i.e. computer-augmented objects integrating room elements with information technology. We present the current realization of i-LAND in terms of an interactive electronic wall, an interactive table, two computer-enhanced chairs, and two "bridges" for the Passage-mechanism. This is complemented by the description of the creativity support application and the technological infrastructure. The paper is accompanied by a video figure in the CHI'99 video program.
Keywords: Integrated design, Interactive landscape, Architectural space, Virtual information space, Augmented reality, Ubiquitous computing, Roomware, Cooperative rooms, Creativity support, Dynamic team work, CSCW, Workspaces of the future
Logjam: A Tangible Multi-Person Interface for Video Logging BIBAKPDF 128-135
  Jonathan Cohen; Meg Withgott; Philippe Piernot
This paper describes the evolution, implementation, and use of logjam, a system for video logging. The system features a game-board that senses the location and identities of pieces placed upon it. The board is the interface that enables a group of people to log video footage together. We report on some of the surprising physical and social dynamics that we have observed in multi-person logging sessions using the system.
Keywords: Tangible user interfaces, TUI, CSCW, Video ethnography, Video logging, User experience, 2D sensing/tracking
Time-Compression: Systems Concerns, Usage, and Benefits BIBAKPDF 136-143
  Nosa Omoigui; Liwei He; Anoop Gupta; Jonathan Grudin; Elizabeth Sanocki
With the proliferation of online multimedia content and the popularity of multimedia streaming systems, it is increasingly useful to be able to skim and browse multimedia quickly. A key technique that enables quick browsing of multimedia is time-compression. Prior research has described how speech can be time-compressed (shortened in duration) while preserving the pitch of the audio. However, client-server systems providing this functionality have not been available.
   In this paper, we first describe the key tradeoffs faced by designers of streaming multimedia systems deploying time-compression. The implementation tradeoffs primarily impact the granularity of time-compression supported (discrete vs. continuous) and the latency (wait-time) experienced by users after adjusting degree of time-compression. We report results of user studies showing impact of these factors on the average-compression-rate achieved. We also present data on the usage patterns and benefits of time compression. Overall, we show significant time-savings for users and that considerable flexibility is available to the designers of client-server streaming systems with time compression.
Keywords: Time-compression, Video browsing, Multimedia, Latency, Compression granularity, Compression rate

Characters and Agents

SWEETPEA: Software Tools for Programmable Embodied Agents BIBAKPDF 144-151
  Michael Kaminsky; Paul Dourish; W. Keith Edwards; Anthony LaMarca; Michael Salisbury; Ian Smith
Programmable Embodied Agents are portable, wireless, interactive devices embodying specific, differentiable, interactive characteristics. They take the form of identifiable characters who reside in the physical world and interact directly with users. They can act as an out-of-band communication channel between users, as proxies for system components or other users, or in a variety of other roles. Traditionally, research into such devices has been based on costly custom hardware. In this paper, we report on our explorations of the space of physical character-based interfaces built on recently available stock consumer hardware platforms, structured around an initial framework of applications.
Keywords: Interaction hardware, Tangible media, Augmented reality, ActiMates Barney, Mattel Talk-With-Me Barbie
Sympathetic Interfaces: Using a Plush Toy to Direct Synthetic Characters BIBAKPDF 152-158
  Michael Patrick Johnson; Andrew Wilson; Bruce Blumberg; Christopher Kline; Aaron Bobick
We introduce the concept of a sympathetic interface for controlling an animated synthetic character in a 3D virtual environment. A plush doll embedded with wireless sensors is used to manipulate the virtual character in an iconic and intentional manner. The interface extends from the novel physical input device through interpretation of sensor data to the behavioral "brain" of the virtual character. We discuss the design of the interface and focus on its latest instantiation in the Swamped! exhibit at SIGGRAPH '98. We also present what we learned from hundreds of casual users, who ranged from young children to adults.
Keywords: Sympathetic interface, Plush toy, Synthetic characters, Physically-based interface, Virtual worlds
Principles of Mixed-Initiative User Interfaces BIBAKPDF 159-166
  Eric Horvitz
Recent debate has centered on the relative promise of focusing user-interface research on developing new metaphors and tools that enhance users' abilities to directly manipulate objects versus directing effort toward developing interface agents that provide automation. In this paper, we review principles that show promise for allowing engineers to enhance human-computer interaction through an elegant coupling of automated services with direct manipulation. Key ideas will be highlighted in terms of the LookOut system for scheduling and meeting management.
Keywords: Intelligent agents, Direct manipulation, User modeling, Probability, Decision theory, UI design

Progress in Drawing and CAD

An Exploration into Supporting Artwork Orientation in the User Interface BIBAKPDF 167-174
  George W. Fitzmaurice; Ravin Balakrishnan; Gordon Kurtenbach; Bill Buxton
Rotating a piece of paper while drawing is an integral and almost subconscious part of drawing with pencil and paper. In a similar manner, the advent of lightweight pen-based computers allow digital artwork to be rotated while drawing by rotating the entire computer. Given this type of manipulation we explore the implications for the user interface to support artwork orientation. First we describe an exploratory study to further motivate our work and characterize how artwork is manipulated while drawing. After presenting some possible UI approaches to support artwork orientation, we define a new solution called a rotating user interface (RUIs). We then discuss design issues and requirements for RUIs based on our exploratory study.
Keywords: Rotating user interfaces, RUI, Pen-based computers, GUI toolkits, Tablets, LCDs, Two-handed input
An Alternative Way of Drawing BIBAKPDF 175-182
  Roope Raisamo
Current object-oriented drawing programs have an established way of drawing in which the shape of an object is controlled by manipulating control points. While the control points are intuitive in their basic use, it is not clear whether they make more complex drawing tasks manageable for the average user. In this paper we describe an alternative way of drawing and editing a drawing using new direct manipulation tools. Our approach resembles sculpting in two dimensions: the user begins with a large block and uses different tools to give it the desired shape. We also present a user evaluation in which the users could try our new tools and compare them to their previous experience of control points. The users claimed to understand the operations better with our tools than if they had needed to use curves and control points. However, our tools were better suited for sketching the artwork than for making very detailed drawings.
Keywords: Drawing programs, Direct manipulation, Two-handed interaction, Interaction techniques, Sculpting
The Strategic Use of CAD: An Empirically Inspired, Theory-Based Course BIBAKPDF 183-190
  Suresh K. Bhavnani; Bonnie E. John; Ulrich Flemming
The inefficient use of complex computer systems has been widely reported. These studies show the persistence of inefficient methods despite many years of experience and formal training. To counteract this phenomenon, we present the design of a new course, called the Strategic Use of CAD. The course aims at teaching students efficient strategies to use a computer-aided drafting system through a two-pronged approach. Learning to See teaches students to recognize opportunities to use efficient strategies by studying the nature of the task, and Learning to Do teaches students to implement the strategies. Results from a pilot experiment show that this approach had a positive effect on the strategic behavior of students who did not exhibit knowledge of efficient strategies before the class, and had no effect on the strategic behavior of those who did. Strategic training can thus assist users in recognizing opportunities to use efficient strategies. We present the ramifications of these results on the design of training and future experiments.
Keywords: CAD, Strategy, Training, GOMS, Learning, Efficiency

Programming Techniques and Issues

Implementing Interface Attachments Based on Surface Representations BIBAKPDF 191-198
  Dan R., Jr. Olsen; Scott E. Hudson; Thom Verratti; Jeremy M. Heiner; Matt Phelps
This paper describes an architecture for supporting interface attachments -- small interactive programs which are designed to augment the functionality of other applications. This architecture is designed to work with a diverse set of conventional applications, but require only a minimal set of "hooks" into those applications. In order to achieve this, the work described here concentrates on what we will call observational attachments, a subclass of attachments that operate primarily by observing and manipulating the surface representations of applications -- that is the visual information that applications would normally display on the screen or print. These attachments can be thought of as "looking" over the shoulder of the user" to assist with various tasks. By requiring very little modification to, or help from, the applications they augment, this approach supports the creation of a set of uniform services that can be applied across a more diverse set of applications than traditional approaches.
Keywords: User interface architectures, Observational attachments, Surface representations, Linking and embedding
A Visual Medium for Programmatic Control of Interactive Applications BIBAKPDF 199-206
  Luke S. Zettlemoyer; Robert St. Amant
The VisMap system provides for "visual manipulation" of arbitrary off-the-shelf applications, through an application's graphical user interface. VisMap's API-independent control has advantages for tasks that can benefit from direct access to the functions of the user interface. We describe the design goals and architecture of the system, and we discuss two applications, a user-controlled visual scripting program and an autonomous solitaire-playing program, which together demonstrate some of the capabilities and limitations of the approach.
Keywords: Interaction techniques, Agents, Demonstrational interfaces, Development tools
Should We Leverage Natural-Language Knowledge? An Analysis of User Errors in a Natural-Language-Style Programming Language BIBAKPDF 207-214
  Amy Bruckman; Elizabeth Edwards
Should programming languages use natural-language-like syntax? Under what circumstances? What sorts of errors do novice programmers make? Does using a natural-language-like programming language lead to user errors? In this study, we read the entire online interactions of sixteen children who issued a total of 35,047 commands on MOOSE Crossing, an educational MUD for children, We counted and categorized the errors made. A total of 2,970 errors were observed. We define "natural-language errors" as those errors in which the user failed to distinguish between English and code, issuing an incorrect command that was more English-like than the correct one. A total of 314 natural-language errors were observed. In most of those errors, the child was able to correct the problem either easily (41.1% of the time) or with some effort (20.7%). Natural-language errors were divided into five categories. In order from most to least frequent, they are: syntax errors, guessing a command name by supplying an arbitrary English word, literal interpretation of metaphor, assuming the system is keeping more state information than is actually the case, and errors of operator precedence and combination. We believe that these error rates are within acceptable limits, and conclude that leveraging users' natural-language knowledge is for many applications an effective strategy for designing end-user-programming languages.
Keywords: Natural language, Novice programming, Programming language design, End-user programming

Touching, Pointing, and Choosing

Testing Pointing Device Performance and User Assessment with the ISO 9241, Part 9 Standard BIBAKPDF 215-222
  Sarah A. Douglas; Arthur E. Kirkpatrick; I. Scott MacKenzie
The ISO 9241, Part 9 Draft International Standard for testing computer pointing devices proposes an evaluation of performance and comfort. In this paper we evaluate the scientific validity and practicality of these dimensions for two pointing devices for laptop computers, a finger-controlled isometric joystick and a touchpad. Using a between-subjects design, evaluation of performance using the measure of throughput was done for one-direction and multi-directional pointing and selecting. Results show a significant difference in throughput for the multi-directional task, with the joystick 27% higher; results from the one-direction task were non-significant. After the experiment, participants rated the device for comfort, including operation, fatigue, and usability. The questionnaire showed no overall difference in the responses, and a significant statistical difference in only the question concerning force required to operate the device -- the joystick requiring slightly more force. The paper concludes with a discussion of problems in implementing the ISO standard and recommendations for improvement.
Keywords: Pointing devices, Ergonomic evaluation, ISO 9241 standard, Isometric joystick, Touchpad, Fitts' law
Touch-Sensing Input Devices BIBAKPDF 223-230
  Ken Hinckley; Mike Sinclair
We can touch things, and our senses tell us when our hands are touching something. But most computer input devices cannot detect when the user touches or releases the device or some portion of the device. Thus, adding touch sensors to input devices offers many possibilities for novel interaction techniques. We demonstrate the TouchTrackball and the Scrolling TouchMouse, which use unobtrusive capacitance sensors to detect contact from the user's hand without requiring pressure or mechanical actuation of a switch. We further demonstrate how the capabilities of these devices can be matched to an implicit interaction technique, the On-Demand Interface, which uses the passive information captured by touch sensors to fade in or fade out portions of a display depending on what the user is doing; a second technique uses explicit, intentional interaction with touch sensors for enhanced scrolling. We present our new devices in the context of a simple taxonomy of tactile input technologies. Finally, we discuss the properties of touch-sensing as an input channel in general.
Keywords: Input devices, Interaction techniques, Sensor technologies, Haptic input, Tactile input, Touch-sensing devices
The Hotbox: Efficient Access to a Large Number of Menu-Items BIBAKPDF 231-237
  Gordon Kurtenbach; George W. Fitzmaurice; Russell N. Owen; Thomas Baudel
The proliferation of multiple toolbars and UI widgets around the perimeter of application windows is an indication that the traditional GUI design of a single menubar is not sufficient to support large scale applications with numerous functions. In this paper we describe a new widget which is an enhancement of the traditional menubar which dramatically increases menu-item capacity. This widget, called the "Hotbox" combines several GUI techniques which are generally used independently: accelerator keys, modal dialogs, pop-up/pull down menus, radial menus, marking menus and menubars. These techniques are fitted together to create a single, easy to learn yet fast to operate GUI widget which can handle significantly more menu-items than the traditional GUI menubar. We describe the design rationale of the Hotbox and its effectiveness in a large scale commercial application. While the Hotbox was developed for a particular application domain, the widget itself and the design rationale are potentially useful in other domains.
Keywords: Menus access, Menubars, Two-handed input, Transparency, Marking menus

Gaze and Purpose

Combining Observations of Intentional and Unintentional Behaviors for Human-Computer Interaction BIBAKPDF 238-245
  Yoshinori Kuno; Tomoyuki Ishiyama; Satoru Nakanishi; Yoshiaki Shirai
Human interfaces are usually designed to respond only to intentional human behaviors. However, humans show unintentional behaviors as well. They can convey useful information to realize user-friendly human interfaces. This paper presents how to combine observations of both types of behaviors by taking two human-machine systems: a gesture-based interface and an intelligent wheelchair. In the first system, intentional hand gestures are chosen using unintentional behaviors. In the second system, near unintentional behaviors following intentional behaviors can be used to control the wheelchair motion. Experimental systems working in real time have been developed. Operational experiments prove our approach promising.
Keywords: Vision-based interface, Gesture-based interface, Wheelchair, Face direction, Intention
Manual and Gaze Input Cascaded (MAGIC) Pointing BIBAKPDF 246-253
  Shumin Zhai; Carlos Morimoto; Steven Ihde
This work explores a new direction in utilizing eye gaze for computer input. Gaze tracking has long been considered as an alternative or potentially superior pointing method for computer input. We believe that many fundamental limitations exist with traditional gaze pointing. In particular, it is unnatural to overload a perceptual channel such as vision with a motor control task. We therefore propose an alternative approach, dubbed MAGIC (Manual And Gaze Input Cascaded) pointing. With such an approach, pointing appears to the user to be a manual task, used for fine manipulation and selection. However, a large portion of the cursor movement is eliminated by warping the cursor to the eye gaze area, which encompasses the target. Two specific MAGIC pointing techniques, one conservative and one liberal, were designed, analyzed, and implemented with an eye tracker we developed. They were then tested in a pilot study. This early-stage exploration showed that the MAGIC pointing techniques might offer many advantages, including reduced physical effort and fatigue as compared to traditional manual pointing, greater accuracy and naturalness than traditional gaze pointing, and possibly faster speed than manual pointing. The pros and cons of the two techniques are discussed in light of both performance data and subjective reports.
Keywords: Gaze, Eye, Computer input, Eye tracking, Gaze tracking, Pointing, Multi-modal interface, Fitts' law, Computer vision
Inferring Intent in Eye-Based Interfaces: Tracing Eye Movements with Process Models BIBAKPDF 254-261
  Dario D. Salvucci
While current eye-based interfaces offer enormous potential for efficient human-computer interaction, they also manifest the difficulty of inferring intent from user eye movements. This paper describes how fixation tracing facilitates the interpretation of eye movements and improves the flexibility and usability of eye-based interfaces. Fixation tracing uses hidden Markov models to map user actions to the sequential predictions of a cognitive process model. In a study of eye typing, results show that fixation tracing generates significantly more accurate interpretations than simpler methods and allows for more flexibility in designing usable interfaces. Implications for future research in eye-based interfaces and multimodal interfaces are discussed.
Keywords: Eye movements, Eye-based interfaces, Tracing, Hidden Markov models, User models, Cognitive models

Foundations for Navigation

Direct Combination BIBAKPDF 262-269
  Simon Holland; Daniel Oppenheim
This paper reports on Direct Combination, a new user interaction technique. Direct Combination may be viewed variously as: a systematic extension to Direct Manipulation; a concise navigational framework to help users find the operations they need; and as a framework to make a greater range and variety of operations available to the user, without overburdening user or interface designer. While Direct Combination may be seen as an extension of Direct Manipulation, it may also be applied to a wide range of user interaction styles, including even command line interfaces. Examples from various hypothetical systems and from an implemented system are presented. This paper argues that Direct Combination is applicable not just to problem seeking or design oriented domains (where the technique originated) but is generally applicable. A variety of new interaction styles for Direct Combination are presented. The generalisation of Direct Combination to the n-dimensional case is presented.
Keywords: Interaction technique, Interaction styles, Interaction design, Navigating large operator spaces, Novel interaction objects, N-tuples, Creating new operations, Interaction theory
Footprints: History-Rich Tools for Information Foraging BIBAKPDF 270-277
  Alan Wexelblat; Pattie Maes
Inspired by Hill and Hollan's original work [7], we have been developing a theory of interaction history and building tools to apply this theory to navigation in a complex information space. We have built a series of tools -- map, paths, annotations and signposts -- based on a physical-world navigation metaphor. These tools have been in use for over a year. Our user study involved a controlled browse task and showed that users were able to get the same amount of work done with significantly less effort.
Keywords: Information navigation, Information foraging, Interaction history, web browsing
Design Guidelines for Landmarks to Support Navigation in Virtual Environments BIBAKPDF 278-285
  Norman G. Vinson
Unfamiliar, large-scale virtual environments are difficult to navigate. This paper presents design guidelines to ease navigation in such virtual environments. The guidelines presented here focus on the design and placement of landmarks in virtual environments. Moreover, the guidelines are based primarily on the extensive empirical literature on navigation in the real world. A rationale for this approach is provided by the similarities between navigational behavior in real and virtual environments.
Keywords: Guidelines, Navigation, Wayfinding, Landmarks, Virtual reality, Virtual environments

Working with People Near and Far

Single Display Groupware: A Model for Co-Present Collaboration BIBAKPDF 286-293
  Jason Stewart; Benjamin B. Bederson; Allison Druin
We introduce a model for supporting collaborative work between people that are physically close to each other. We call this model Single Display Groupware (SDG). In this paper, we describe the model, comparing it to more traditional remote collaboration. We describe the requirements that SDG places on computer technology, and our understanding of the benefits and costs of SDG systems. Finally, we describe a prototype SDG system that we built and the results of a usability test we ran with 60 elementary school children.
Keywords: CSCW, Single display groupware, Children, Educational applications, Input devices, Pad++, KidPad
The GAZE Groupware System: Mediating Joint Attention in Multiparty Communication and Collaboration BIBAKPDF 294-301
  Roel Vertegaal
In this paper, we discuss why, in designing multiparty mediated systems, we should focus first on providing non-verbal cues which are less redundantly coded in speech than those normally conveyed by video. We show how conveying one such cue, gaze direction, may solve two problems in multiparty mediated communication and collaboration: knowing who is talking to whom, and who is talking about what. As a candidate solution, we present the GAZE Groupware System, which combines support for gaze awareness in multiparty mediated communication and collaboration with small and linear bandwidth requirements. The system uses an advanced, desk-mounted eyetracker to metaphorically convey gaze awareness in a 3D virtual meeting room and within shared documents.
Keywords: CSCW, Multiparty videoconferencing, Awareness, Attention, Gaze direction, Eyetracking, VRML 2
Video Helps Remote Work: Speakers Who Need to Negotiate Common Ground Benefit from Seeing Each Other BIBAKPDF 302-309
  Elizabeth S. Veinott; Judith Olson; Gary M. Olson; Xiaolan Fu
More and more organizations are forming teams that are not co-located. These teams communicate via email, fax, telephone and audio conferences, and sometimes video. The question often arises whether the cost of video is worth it. Previous research has shown that video makes people more satisfied with the work, but it doesn't help the quality of the work itself. There is one exception; negotiation tasks are measurably better with video. In this study, we show that the same effect holds for a more subtle form of negotiation, when people have to negotiate meaning in a conversation. We compared the performance and communication of people explaining a map route to each other. Half the pairs have video and audio connections, half only audio. Half of the pairs were native speakers of English; the other half were non-native speakers, those presumably who have to negotiate meaning more. The results showed that non-native speaker pairs did benefit from the video; native speakers did not. Detailed analysis of the conversational strategies showed that with video, the non-native speaker pairs spent proportionately more effort negotiating common ground.
Keywords: Video-mediated communication, Remote work, Common ground, Communication, Negotiation

Stories and Narratives

Designing Multimedia for Learning: Narrative Guidance and Narrative Construction BIBAKPDF 310-317
  Lydia Plowman; Rosemary Luckin; Diana Laurillard; Matthew Stratfold; Josie Taylor
Narrative is fundamental to the ways we make sense of texts of all kinds because it provides structure and coherence, but it is difficult to see how this works in the context of multimedia interactive learning environments (MILEs). We tested our hypotheses about the form and function of narrative in MILEs by developing three versions of material on CD-ROM which had different narrative structures and analysed the impact of the different versions on learner behaviour. We present a theoretical framework in which we explain the concepts of narrative guidance and narrative construction and their application to the design of MILEs.
Keywords: Narrative, Multimedia design, Education
Interactive 3D Sound Hyperstories for Blind Children BIBAKPDF 318-325
  Mauricio Lumbreras; Jaime Sanchez
Interactive software is currently used for learning and entertainment purposes. This type of software is not very common among blind children because most computer games and electronic toys do not have appropriate interfaces to be accessible without visual cues.
   This study introduces the idea of interactive hyperstories carried out in a 3D acoustic virtual world for blind children. We have conceptualized a model to design hyperstories. Through AudioDoom we have an application that enables testing cognitive tasks with blind children. The main research question underlying this work explores how audio-based entertainment and spatial sound navigable experiences can create cognitive spatial structures in the minds of blind children.
   AudioDoom presents first person experiences through exploration of interactive virtual worlds by using only 3D aural representations of the space.
Keywords: Virtual acoustic environment, Space representation, Blind children, Audio-based navigation, Hyperstory, 3D sound, Audio interface

Video: Stories and Narratives

Designing PETS: A Personal Electronic Teller of Stories BIBAKPDF 326-329
  Allison Druin; Jaime Montemayor; Jim Handler; Britt McAlister; Angela Boltman; Eric Fiterman; Aurelie Plaisant; Alex Kruskal; Hanne Olsen; Isabella Revett; Thomas Plaisant Schwenn; Lauren Sumida; Rebecca Wagner
We have begun the development of a new robotic pet that can support children in the storytelling process. Children can build their own pet by snapping together the modular animal parts of the PETS robot. After their pet is built, children can tell stories using the My Pets software. These stories can then be acted out by their robotic pet. This video paper describes the motivation for this research and the design process of our intergenerational design team in building the first PETS prototypes. We will discuss our progress to date and our focus for the future.
Keywords: Children, Design techniques, Educational applications, Cooperative inquiry, Intergenerational design team, PETS, Robotics

Profiles, Notes, and Surfaces

Visual Profiles: A Critical Component of Universal Access BIBAKPDF 330-337
  Julie A. Jacko; Max A. Dixon; Robert H., Jr. Rosa; Ingrid U. Scott; Charles J. Pappas
This research focuses on characterizing visually impaired computer users' performance on graphical user interfaces by linking clinical assessments of low vision with visual icon identification. This was accomplished by evaluating user performance on basic identification and selection tasks within a graphical user interface, comparing partially sighted user performance with fully sighted user performance, and linking task performance to specific profiles of visual impairment. Results indicate that visual acuity, contrast sensitivity, visual field and color perception were significant predictors of task performance. In addition, icon size and background color significantly influenced performance. Suggestions for future research are provided.
Keywords: Universal access, Low vision, Visual icons, Disabilities
NotePals: Lightweight Note Sharing by the Group, for the Group BIBAKPDF 338-345
  Richard C. Davis; James A. Landay; Victor Chen; Jonathan Huang; Rebecca B. Lee; Francis C. Li; James Lin; Charles B., III Morrey; Ben Schleimer; Morgan N. Price; Bill N. Schilit
NotePals is a lightweight note sharing system that gives group members easy access to each other's experiences through their personal notes. The system allows notes taken by group members in any context to be uploaded to a shared repository. Group members view these notes with browsers that allow them to retrieve all notes taken in a given context or to access notes from other related notes or documents. This is possible because NotePals records the context in which each note is created (e.g., its author, subject, and creation time). The system is "lightweight" because it fits easily into group members' regular note-taking practices, and uses informal, ink-based user interfaces that run on portable, inexpensive hardware. In this paper we describe NotePals, show how we have used it to share our notes, and present our evaluations of the system.
Keywords: CSCW, PDA, Pen-based user interface, Digital ink, Mobile computing, Informal user interfaces, NotePals
Flatland: New Dimensions in Office Whiteboards BIBAKPDF 346-353
  Elizabeth D. Mynatt; W. Keith Edwards; Anthony LaMarca; Takeo Igarashi
Flatland is an augmented whiteboard interface designed for informal office work. Our research investigates approaches to building an augmented whiteboard in the context of continuous, long term office use. In particular, we pursued three avenues of research based on input from user studies: techniques for the management of space on the board, the ability to flexibly apply behaviors to support varied application semantics, and mechanisms for managing history on the board. Unlike some previously reported whiteboard systems, our design choices have been influenced by a desire to support long-term, informal use in an individual office setting.
Keywords: Pen-based computing, Whiteboards, Ubiquitous computing, Light-weight interaction, Flatland

Tagging and Tracking Objects in Physical UIs

Palette: A Paper Interface for Giving Presentations BIBAKPDF 354-361
  Les Nelson; Satoshi Ichimura; Elin Ronby Pedersen; Lia Adams
The Palette is a digital appliance designed for intuitive control of electronic slide shows. Current interfaces demand too much of our attention to permit effective computer use in situations where we can not give the technology our fullest concentration. The Palette uses index cards that are printed with slide content that is easily identified by both humans and computers. The presenter controls the presentation by directly manipulating the cards. The Palette design is based on our observation of presentations given in a real work setting. Our experiences using the system are described, including new practices (e.g., collaborative presentation, enhanced notetaking) that arise from the affordances of this new approach. This system is an example of a new interaction paradigm called tacit interaction that supports users who can spare very little attention to a computer interface.
Keywords: Paper interfaces, Presentation appliance, Interaction design, Physically embodied interfaces, Tacit interaction
TouchCounters: Designing Interactive Electronic Labels for Physical Containers BIBAKPDF 362-369
  Paul Yarin; Hiroshi Ishii
We present TouchCounters, an integrated system of electronic modules, physical storage containers, and shelving surfaces for the support of collaborative physical work. Through physical sensors and local displays, TouchCounters record and display usage history information upon physical storage containers, thus allowing access to this information during the performance of real-world tasks. A distributed communications network allows this data to be exchanged with a server, such that users can access this information from remote locations as well.
   Based upon prior work in ubiquitous computing and tangible interfaces, TouchCounters incorporate new techniques, including usage history tracking for physical objects and multi-display visualization. This paper describes the components, interactions, implementation, and conceptual approach of the TouchCounters system.
Keywords: Tangible interfaces, Ubiquitous computing, Distributed sensing, Visualization
Bridging Physical and Virtual Worlds with Electronic Tags BIBAKPDF 370-377
  Roy Want; Kenneth P. Fishkin; Anuj Gujar; Beverly L. Harrison
The role of computers in the modern office has divided our activities between virtual interactions in the realm of the computer and physical interactions with real objects within the traditional office infrastructure. This paper extends previous work that has attempted to bridge this gap, to connect physical objects with virtual representations or computational functionality, via various types of tags. We discuss a variety of scenarios we have implemented using a novel combination of inexpensive, unobtrusive and easy to use RFID tags, tag readers, portable computers and wireless networking. This novel combination demonstrates the utility of invisibly, seamlessly and portably linking physical objects to networked electronic services and actions that are naturally associated with their form.
Keywords: RFID tag, Portable computers, Wireless networks, Ubiquitous computing, Tangible interface, Phicon, Augmented reality

Augmented Surfaces

Augmented Surfaces: A Spatially Continuous Work Space for Hybrid Computing Environments BIBAKPDF 378-385
  Jun Rekimoto; Masanori Saitoh
This paper describes our design and implementation of a computer augmented environment that allows users to smoothly interchange digital information among their portable computers, table and wall displays, and other physical objects. Supported by a camera-based object recognition system, users can easily integrate their portable computers with the pre-installed ones in the environment. Users can use displays projected on tables and walls as a spatially continuous extension of their portable computers. Using an interaction technique called hyperdragging, users can transfer information from one computer to another, by only knowing the physical relationship between them. We also provide a mechanism for attaching digital data to physical objects, such as a videotape or a document folder, to link physical and digital spaces.
Keywords: Multiple device user interfaces, Table-sized displays, Wall-sized displays, Portable computers, Ubiquitous computing, Architectural media, Physical space, Augmented reality
Urp: A Luminous-Tangible Workbench for Urban Planning and Design BIBAKPDF 386-393
  John Underkoffler; Hiroshi Ishii
We introduce a system for urban planning -- called Urp -- that integrates functions addressing a broad range of the field's concerns into a single, physically based workbench setting. The I/O Bulb infrastructure on which the application is based allows physical architectural models placed on an ordinary table surface to cast shadows accurate for arbitrary times of day; to throw reflections off glass facade surfaces; to affect a real-time and visually coincident simulation of pedestrian-level windflow; and so on.
   We then use comparisons among Urp and several earlier I/O Bulb applications as the basis for an understanding of luminous-tangible interactions, which result whenever an interface distributes meaning and functionality between physical objects and visual information projectively coupled to those objects. Finally, we briefly discuss two issues common to all such systems, offering them as informal thought-tools for the design and analysis of luminous-tangible interfaces.
Keywords: Urban design, Urban planning, Architectural simulation, Luminous-tangible interface, Direct manipulation, Augmented reality, Prototyping tool, Interactive projection, Tangible bits
PingPongPlus: Design of an Athletic-Tangible Interface for Computer-Supported Cooperative Play BIBAKPDF 394-401
  Hiroshi Ishii; Craig Wisneski; Julian Orbanes; Ben Chun; Joe Paradiso
This paper introduces a novel interface for digitally-augmented cooperative play. We present the concept of the "athletic-tangible interface," a new class of interaction which uses tangible objects and full-body motion in physical spaces with digital augmentation. We detail the implementation of PingPongPlus, a "reactive ping-pong table", which features a novel sound-based ball tracking technology. The game is augmented and transformed with dynamic graphics and sound, determined by the position of impact, and the rhythm and style of play. A variety of different modes of play and initial experiences with PingPongPlus are also described.
Keywords: Tangible interface, Enhanced reality, Augmented reality, Interactive surface, Athletic interaction, Kinesthetic interaction, Computer-supported cooperative play

Cognitive Models of Screen Interaction

Eye Tracking the Visual Search of Click-Down Menus BIBAKPDF 402-409
  Michael D. Byrne; John R. Anderson; Scott Douglass; Michael Matessa
Click-down (or pull-down) menus have long been a key component of graphical user interfaces, yet we know surprisingly little about how users actually interact with such menus. Nilsen's [8] study on menu selection has led to the development of a number of models of how users perform the task [6, 21. However, the validity of these models has not been empirically assessed with respect to eye movements (though [1] presents some interesting data that bear on these models). The present study is an attempt to provide data that can help refine our understanding of how users interact with such menus.
Keywords: Menu selection, Eye tracking, Visual search, Cognitive models
Cognitive Modeling Demonstrates How People Use Anticipated Location Knowledge of Menu Items BIBAKPDF 410-417
  Anthony J. Hornof; David E. Kieras
This research presents cognitive models of a person selecting an item from a familiar, ordered, pull-down menu. Two different models provide a good fit with human data and thus two different possible explanations for the low-level cognitive processes involved in the task. Both models assert that people make an initial eye and hand movement to an anticipated target location without waiting for the menu to appear. The first model asserts that a person knows the exact location of the target item before the menu appears, but the model uses nonstandard Fitts' law coefficients to predict mouse pointing time. The second model asserts that a person would only know the approximate location of the target item, and the model uses Fitts' law coefficients better supported by the literature. This research demonstrates that people can develop considerable knowledge of locations in a visual task environment, and that more work regarding Fitts' law is needed.
Keywords: Cognitive models, Fitts' law, Menus, Visual search
Learning and Performing by Exploration: Label Quality Measured by Latent Semantic Analysis BIBAKPDF 418-425
  Rodolfo Soto
Models of learning and performing by exploration assume that the semantic similarity between task descriptions and labels on display objects (e.g., menus, tool bars) controls in part the users' search strategies. Nevertheless, none of the models has an objective way to compute semantic similarity. In this study, Latent Semantic Analysis (LSA) was used to compute semantic similarity between task descriptions and labels in an application's menu system. Participants performed twelve tasks by exploration and they were tested for recall after a 1-week delay. When the labels in the menu system were semantically similar to the task descriptions, subjects performed the tasks faster. LSA could be incorporated into any of the current models, and it could be used to automate the evaluation of computer applications for ease of learning and performing by exploration.
Keywords: Learning by exploration, Label-following strategy, Cognitive models, Semantic similarity, Latent semantic analysis, Usability analysis

Tools for Building Interfaces and Applications

MOBILE: User-Centered Interface Building BIBAKPDF 426-433
  Angel R. Puerta; Eric Cheng; Tunhow Ou; Justin Min
Interface builders are popular tools for designing and developing graphical user interfaces. These tools, however, are engineering-centered; they operate mainly on windows and widgets. A typical interface builder does not offer any specific support for user-centered interface design, a methodology recognized as critical for effective user interface design. We present MOBILE (Model-Based Interface Layout Editor) an interface building tool that fully supports user-centered design and that guides the interface building process by using user-task models and a knowledge base of interface design guidelines. The approach in MOBILE has the important added benefit of being useful in both top-down and bottom-up interface design strategies.
Keywords: Model-based interface development, Task models, Interface builders, User-centered interface design, User interface development tools
The Context Toolkit: Aiding the Development of Context-Enabled Applications BIBAKPDF 434-441
  Daniel Salber; Anind K. Day; Gregory D. Abowd
Context-enabled applications are just emerging and promise richer interaction by taking environmental context into account. However, they are difficult to build due to their distributed nature and the use of unconventional sensors. The concepts of toolkits and widget libraries in graphical user interfaces has been tremendously successful, allowing programmers to leverage off existing building blocks to build interactive systems more easily. We introduce the concept of context widgets that mediate between the environment and the application in the same way graphical widgets mediate between the user and the application. We illustrate the concept of context widgets with the beginnings of a widget library we have developed for sensing presence, identity and activity of people and things. We assess the success of our approach with two example context-enabled applications we have built and an existing application to which we have added context-sensing capabilities.
Keywords: Context-enabled or context-aware computing, Ubiquitous computing, Toolkits, Widgets, Applications development
Getting More Out of Programming-by-Demonstration BIBAKPDF 442-449
  Richard G. McDaniel; Brad A. Myers
Programming-by-demonstration (PBD) can be used to create tools and methods that eliminate the need to learn difficult computer languages. Gamut is a PBD tool that nonprogrammers can use to create a broader range of interactive software, including games, simulations, and educational software, than they can with other PBD tools. To do this, Gamut provides advanced interaction techniques that make it easier for a developer to express all aspects of an application. These techniques include a simplified way to demonstrate new examples, called "nudges," and a way to highlight objects to show they are important. Also, Gamut includes new objects and metaphors like the deck-of-cards metaphor for demonstrating collections of objects and randomness, guide objects for demonstrating relationships that the system would find too difficult to guess, and temporal ghosts which simplify showing relationships with the recent past. These techniques were tested in a formal setting with nonprogrammers to evaluate their effectiveness.
Keywords: End-user programming, User interface software, Programming-by-demonstration, Programming-by-example, Application builders, Inductive learning, Gamut

Vision and Fitts' Law

Navigation as Multiscale Pointing: Extending Fitts' Model to Very High Precision Tasks BIBAKPDF 450-457
  Yves Guiard; Michel Beaudouin-Lafon; Deni Mottet
Fitts' pointing model has proven extremely useful for understanding basic selection in WIMP user interfaces. Yet today's interfaces involve more complex navigation within electronic environments. As navigation amounts to a form of multi-scale pointing, Fitts' model can be applied to these more complex tasks. We report the results of a preliminary pointing experiment that shows that users can handle higher levels of task difficulty with two-scale rather than traditional one-scale pointing control. Also, in tasks with very high-precision hand movements, performance is higher with a stylus than with a mouse.
Keywords: Fitts' law, Pointing, Navigation, Multiscale interfaces, Input devices, Stylus, Mouse, Graphical tablet
Authoring Animated Web Pages Using 'Contact Points' BIBAKPDF 458-465
  Pete Faraday; Alistair Sutcliffe
This paper explores how 'contact points' or co-references between an animation and text should be designed in web pages. Guidelines are derived from an eye tracking study. A dynamic HTML authoring tool is described which supports these requirements. An evaluation study is reported in which four designs of animation in web pages were tested.
Keywords: Web page design, Authoring tools
Performance Evaluation of Input Devices in Trajectory-Based Tasks: An Application of The Steering Law BIBAKPDF 466-472
  Johnny Accot; Shumin Zhai
Choosing input devices for interactive systems that best suit user's needs remains a challenge, especially considering the increasing number of devices available. The choice often has to be made through empirical evaluations. The most frequently used evaluation task hitherto is target acquisition, a task that can be accurately modeled by Fitts' law. However, today's use of computer input devices has gone beyond target acquisition alone. In particular, we often need to perform trajectory-based tasks, such as drawing, writing, and navigation. This paper illustrates how a recently discovered model, the steering law, can be applied as an evaluation paradigm complementary to Fitts' law. We tested five commonly used computer input devices in two steering tasks, one linear and one circular. Results showed that subjects' performance with the five devices could be generally classified into three groups in the following order: 1. the tablet and the mouse, 2. the trackpoint, 3. the touchpad and the trackball. The steering law proved to hold for all five devices with greater than 0.98 correlation. The ability to generalize the experimental results and the limitations of the steering law are also discussed.
Keywords: Steering laws, Input devices, Fitts' law, Human performance modeling, Empirical comparison

Learning and Reading

Symphony: A Case Study in Extending Learner-Centered Design Through Process Space Analysis BIBAKPDF 473-480
  Chris Quintana; Jim Eng; Andrew Carra; Hsin-Kai Wu; Elliot Soloway
We are exploring a new class of tools for learners: scaffolded integrated tool environments (or SITEs), which address the needs of learners trying to engage in new, complex work processes. A crucial phase within a learner-centered design approach for SITE design involves analyzing the work process to identify areas where learners need support to engage in the process. Here we discuss the design of Symphony, a SITE for high-school science students. Specifically, we discuss how the process-space model helped us analyze the science inquiry process to help us identify a detailed set of learner needs, leading to a full set of process scaffolding strategies for Symphony.
Keywords: Learner-centered design, Process spaces, Process scaffolding, Scaffolded integrated tool environments
The Reader's Helper: A Personalized Document Reading Environment BIBAKPDF 481-488
  Jamey Graham
Over the last two centuries, reading styles have shifted away from the reading of documents from beginning to end and toward the skimming of documents in search of relevant information. This trend continues today where readers, often confronted with an insurmountable amount of text, seek more efficient methods of extracting relevant information from documents. In this paper, a new document reading environment is introduced called the Reader's Helper, which supports the reading of electronic and paper documents. The Reader's Helper analyzes documents and produces a relevance score for each of the reader's topics of interest, thereby helping the reader decide whether the document is actually worth skimming or reading. Moreover, during the analysis process, topic of interest phrases are automatically annotated to help the reader quickly locate relevant information. A new information visualization tool, called the Thumbar, is used in conjunction with relevancy scoring and automatic annotation to portray a continuous, dynamic thumb-nail representation of the document. This further supports rapid navigation of the text.
Keywords: Document annotation, Information visualization, Content recognition, Intelligent agents, Digital libraries, Probabilistic reasoning, User interface design, Reading online
VR's Frames of Reference: A Visualization Technique for Mastering Abstract Multidimensional Information BIBAKPDF 489-495
  Marilyn C. Salzman; Chris Dede; R. Bowen Loftin
This paper describes a research study that investigated how designers can use frames of reference (egocentric, exocentric, and a combination of the two) to support the mastery of abstract multidimensional information. The primary focus of this study was the relationship between FORs and mastery; the secondary focus was on other factors (individual characteristics and interaction experience) that were likely to influence the relationship between FORs and mastery. This study's outcomes (1) clarify how FORs work in conjunction with other factors in shaping mastery, (2) highlight strengths and weaknesses of different FORs, (3) demonstrate the benefits of providing multiple FORs, and (4) provide the basis for our recommendations to HCI researchers and designers.
Keywords: Virtual reality, Visualization, Interaction design, Visual design, Education applications

Navigation and Visualization

FotoFile: A Consumer Multimedia Organization and Retrieval System BIBAKPDF 496-503
  Allan Kuchinsky; Celine Pering; Michael L. Creech; Dennis Freeze; Bill Serra; Jacek Gwizdka
FotoFile is an experimental system for multimedia organization and retrieval, based upon the design goal of making multimedia content accessible to non-expert users. Search and retrieval are done in terms that are natural to the task. The system blends human and automatic annotation methods. It extends textual search, browsing, and retrieval technologies to support multimedia data types.
Keywords: Multimedia computing, Information organization, Retrieval, Browsing, Visualization, Content-based indexing and retrieval, Digital photography, Digital video, Metadata, Media objects
Hyper Mochi Sheet: A Predictive Focusing Interface for Navigating and Editing Nested Networks through a Multifocus Distortion-Oriented View BIBAKPDF 504-511
  Masashi Toyoda; Etsuya Shibayama
Multi-focus distortion-oriented views are useful in viewing large information on a small screen, but still have problems in managing multiple foci during editing. The user may have to navigate information space by focusing and defocusing multiple parts to obtain multi-focus layouts that change according to various editing situations. As a result, it becomes haphazard to navigate and edit large nested networks such as hypertexts. We propose a user interface for quickly obtaining desirable layouts. The interface uses two techniques: focus size prediction and predictive focus selection. These techniques are based on a user test and experiences in applications. We also describe two example applications.
Keywords: Distortion-oriented view, Multi-focus, Editing, Navigation suitable for a particular editing situation, which changes frequently during editing
Excentric Labeling: Dynamic Neighborhood Labeling for Data Visualization BIBAKPDF 512-519
  Jean-Daniel Fekete; Catherine Plaisant
The widespread use of information visualization is hampered by the lack of effective labeling techniques. An informal taxonomy of labeling methods is proposed. We then describe "excentric labeling", a new dynamic technique to label a neighborhood of objects located around the cursor. This technique does not intrude into the existing interaction, it is not computationally intensive, and was easily applied to several visualization applications. A pilot study with eight subjects indicates a strong speed benefit over a zoom interface for tasks that involve the exploration of large numbers of objects. Observations and comments from users are presented.
Keywords: Visualization, Label, Dynamic labeling, Evaluation

Virtual Reality and Embodiment

Embodiment in Conversational Interfaces: Rea BIBAKPDF 520-527
  J. Cassell; T. Bickmore; M. Billinghurst; L. Campbell; K. Chang; H. Vilhjalmsson; H. Yan
In this paper, we argue for embodied conversational characters as the logical extension of the metaphor of human-computer interaction as a conversation. We argue that the only way to fully model the richness of human face-to-face communication is to rely on conversational analysis that describes sets of conversational behaviors as fulfilling conversational functions, both interactional and propositional. We demonstrate how to implement this approach in Rea, an embodied conversational agent that is capable of both multimodal input understanding and output generation in a limited application domain. Rea supports both social and task-oriented dialogue. We discuss issues that need to be addressed in creating embodied conversational agents, and describe the architecture of the Rea interface.
Keywords: Conversational characters, Multimodal input, Intelligent agents, Multimodal output
Emotional Interfaces for Interactive Aardvarks: Designing Affect into Social Interfaces for Children BIBAKPDF 528-535
  Erik Strommen; Kristin Alexander
Character-based social interfaces present a unique opportunity to integrate emotion into technology interactions. The present paper reports on the use of three emotional interactions (humor, praise, and affection) in the audio interfaces for two character-based interactive learning toys. The reasons for selecting the emotions used, the design rationale for their application, and findings from usability testing are reviewed. It is suggested that as a form of pretend play-acting akin to puppetry, social interfaces can engage the emotions of users in a variety of beneficial ways.
Keywords: Learning, Audio interface, Children, Social interface, Emotion
Bridging Strategies for VR-Based Learning BIBAKPDF 536-543
  Tom Moher; Stellan Ohlsson; Andrew Johnson; Mark Gillingham
A distributed immersive virtual environment was deployed as a component of a pedagogical strategy for teaching third grade children that the Earth is round. The displacement strategy is based on the theory that fundamental conceptual change requires an alternative cognitive starting point which doesn't invoke the features of pre-existing models. While the VR apparatus helped to establish that alternative framework, conceptual change was strongly influenced by the bridging activities which related that experience to the target domain. Simple declarations of relevance proved ineffective. A more articulated bridging process involving physical models was effective for some children, but the multiple representations employed required too much model-matching for others.
Keywords: Learning environments, Conceptual change, Virtual reality, User models

Organizing Information on the Web

The Tangled Web We Wove: A Taskonomy of W\NW Use BIBAKPDF 544-551
  Michael D. Byrne; Bonnie E. John; Neil S. Wehrle; David C. Crow
A prerequisite to the effective design of user interfaces is an understanding of the tasks for which that interface will actually be used. Surprisingly little task analysis has appeared for one of the most discussed and fastest-growing computer applications, browsing the World-Wide Web (WWW). Based on naturally-collected verbal protocol data, we present a taxonomy of tasks undertaken on the WWW. The data reveal that several previous claims about browsing behavior are questionable, and suggests that that widget-centered approaches to interface design and evaluation may be incomplete with respect to good user interfaces for the Web.
Keywords: World-Wide Web, Task analysis, Video protocols
An Empirical Evaluation of User Interfaces for Topic Management of Web Sites BIBAKPDF 552-559
  Brian Amento; Will Hill; Loren Terveen; Peter Ju; Deborah Hix
Topic management is the task of gathering, evaluating, organizing, and sharing a set of web sites for a specific topic. Current web tools do not provide adequate support for this task. We created the TopicShop system to address this need. TopicShop includes (1) a webcrawler that discovers relevant web sites and builds site profiles, and (2) user interfaces for exploring and organizing sites. We conducted an empirical study comparing user performance with TopicShop vs. Yahoo. TopicShop subjects found over 80% more high-quality sites (where quality was determined by independent expert judgements) while browsing only 81% as many sites and completing their task in 89% of the time. The site profile data that TopicShop provides -- in particular, the number of pages on a site and the number of other sites that link to it -- was the key to these results, as users exploited it to identify the most promising sites quickly and easily.
Keywords: Information access, Information retrieval, Information visualization, Human-computer interaction, Computer supported cooperative work, Social filtering
Visualizing Implicit Queries for Information Management and Retrieval BIBAKPDF 560-567
  Mary Czerwinski; Susan Dumais; George Robertson; Susan Dziadosz; Scott Tiernan; Maarten van Dantzich
In this paper, we describe the use of similarity metrics in a novel visual environment for storing and retrieving favorite web pages. The similarity metrics, called Implicit Queries, are used to automatically highlight stored web pages that are related to the currently selected web page. Two experiments explored how users manage their personal web information space with and without the Implicit Query highlighting and later retrieve their stored web pages. When storing and organizing web pages, users with Implicit Query highlighting generated slightly more categories. Implicit Queries also led to faster web page retrieval time, although the results were not statistically significant.
Keywords: Information management, Information retrieval, 3D, Similarity, Categorization, Information visualization, Classification
Note: An earlier version of this article was included by mistake in the printed volume of the CHI '99 Proceedings. This, the correct version, is inserted her in the ACM Digital Library. The original may be found at: http://www.acm.org/pubs/articles/proceedings/chi/302979/p560-czerwinski/p560-czerwinski.printversion.pdf

Speech and Multimodal Interfaces

Patterns of Entry and Correction in Large Vocabulary Continuous Speech Recognition Systems BIBAKPDF 568-575
  Clare-Marie Karat; Christine Halverson; John Karat; Daniel Horn
A study was conducted to evaluate user performance and satisfaction in completion of a set of text creation tasks using three commercially available continuous speech recognition systems. The study also compared user performance on similar tasks using keyboard input. One part of the study (Initial Use) involved 24 users who enrolled, received training and carried out practice tasks, and then completed a set of transcription and composition tasks in a single session. In a parallel effort (Extended Use), four researchers used speech recognition to carry out real work tasks over 10 sessions with each of the three speech recognition software products. This paper presents results from the Initial Use phase of the study along with some preliminary results from the Extended Use phase. We present details of the kinds of usability and system design problems likely in current systems and several common patterns of error correction that we found.
Keywords: Speech recognition, Input techniques, Speech user interfaces, Analysis methods
Mutual Disambiguation of Recognition Errors in a Multimodal Architecture BIBAKPDF 576-583
  Sharon Oviatt
As a new generation of multimodal/media systems begins to define itself, researchers are attempting to learn how to combine different modes into strategically integrated whole systems. In theory, well designed multimodal systems should be able to integrate complementary modalities in a manner that supports mutual disambiguation (MD) of errors and leads to more robust performance. In this study, over 2,000 multimodal utterances by both native and accented speakers of English were processed by a multimodal system, and then logged and analyzed. The results confirmed that multimodal systems can indeed support significant levels of MD, and also higher levels of MD for the more challenging accented users. As a result, although speech recognition as a stand-alone performed far more poorly for accented speakers, their multimodal recognition rates did not differ from those of native speakers. Implications are discussed for the development of future multimodal architectures that can perform in a more robust and stable manner than individual recognition technologies. Also discussed is the design of interfaces that support diversity in tangible ways, and that function well under challenging real-world usage conditions.
Keywords: Multimodal architecture, Speech and pen input, Recognition errors, Mutual disambiguation, Robust performance, Diverse users
Model-Based and Empirical Evaluation of Multimodal Interactive Error Correction BIBAKPDF 584-591
  Bernhard Suhm; Alex Waibel; Brad Myers
Our research addresses the problem of error correction in speech user interfaces. Previous work hypothesized that switching modality could speed up interactive correction of recognition errors (so-called multimodal error correction). We present a user study that compares, on a dictation task, multimodal error correction with conventional interactive correction, such as speaking again, choosing from a list, and keyboard input. Results show that multimodal correction is faster than conventional correction without keyboard input, but slower than correction by typing for users with good typing skills. Furthermore, while users initially prefer speech, they learn to avoid ineffective correction modalities with experience. To extrapolate results from this user study we developed a performance model of multimodal interaction that predicts input speed including time needed for error correction. We apply the model to estimate the impact of recognition technology improvements on correction speeds and the influence of recognition accuracy and correction method on the productivity of dictation systems. Our model is a first step towards formalizing multimodal (recognition-based) interaction.
Keywords: Multimodal interaction, Interactive error correction, Quantitative performance model, Speech and pen input, Speech user interfaces

Advances in User Participation

Cooperative Inquiry: Developing New Technologies for Children with Children BIBAKPDF 592-599
  Allison Druin
In today's homes and schools, children are emerging as frequent and experienced users of technology [3, 14]. As this trend continues, it becomes increasingly important to ask if we are fulfilling the technology needs of our children. To answer this question, I have developed a research approach that enables young children to have a voice throughout the technology development process. In this paper, the techniques of cooperative inquiry will be described along with a theoretical framework that situates this work in the HCI literature. Two examples of technology resulting from this approach will be presented, along with a brief discussion on the design-centered learning of team researchers using cooperative inquiry.
Keywords: Children, Design techniques, Educational applications, Cooperative design, Participatory design, Cooperative inquiry, Intergenerational design team, KidPad, PETS
Projected Realities: Conceptual Design for Cultural Effect BIBAKPDF 600-607
  William Gaver; Anthony Dunne
As a part of a European Union sponsored project, we have proposed a system which aggregates people's expressions over a widening network of public electronic displays in a massive Dutch housing development. Reflecting ideas from contemporary arts as well as from research on media spaces, this is an example of a conceptual design intended to produce meaningful effects on a local culture. In this paper, we describe the methods and ideas that led to this proposal, as an example of research on technologies from the traditions of artist-designers.
Keywords: Design research, Conceptual art, Collaborative systems, Awareness
Customer-Focused Design Data in a Large, Multi-Site Organization BIBAKPDF 608-615
  Paula Curtis; Tammy Heiserman; David Jobusch; Mark Notess; Jayson Webb
Qualitative user-centered design processes such as contextual inquiry can generate huge amounts of data to be organized, analyzed, and represented. When you add the goal of spreading the resultant understanding to the far reaches of a large, multi-site organization, many practical barriers emerge.
   In this paper we describe experience creating and communicating representations of contextually derived user data in a large, multi-site product development organization. We describe how we involved a distributed team in data collection and analysis and how we made the data representations portable. We then describe how we have engaged over 200 people from five sites in thinking through the user data and its implications on product design.
Keywords: Contextual design, Contextual inquiry, Affinity, User data, Customer-focused design, Organizational change, Distributed teams