| Editorial | | BIB | 1 | |
| Dan R., Jr. Olsen | |||
| Integrality and Separability of Input Devices | | BIBAK | PDF | 3-26 | |
| Robert J. K. Jacob; Linda E. Sibert; Daniel C. McFarlane; M. Preston, Jr. Mullen | |||
| Current input device taxonomies and other frameworks typically emphasize the
mechanical structure of input devices. We suggest that selecting an
appropriate input device for an interactive task requires looking beyond the
physical structure of devices to the deeper perceptual structure of the task,
the device, and the interrelationship between the perceptual structure of the
task and the control properties of the device. We affirm that perception is
key to understanding performance of multidimensional input devices on
multidimensional tasks. We have therefore extended the theory of processing of
perceptual structure to graphical interactive tasks and to the control
structure of input devices. This allows us to predict task and device
combinations that lead to better performance and hypothesize that performance
is improved when the perceptual structure of the task matches the control
structure of the device. We conducted an experiment in which subjects
performed two tasks with different perceptual structures, using two input
devices with correspondingly different control structures, a three-dimensional
tracker and a mouse. We analyzed both speed and accuracy, as well as the
trajectories generated by subjects as they used the unconstrained
three-dimensional tracker to perform each task. The results support our
hypothesis and confirm the importance of matching the perceptual structure of
the task and the control structure of the input device. Keywords: Models and principles, User/machine systems, Human factors, Information
interfaces and presentation, User interfaces, Input devices and strategies,
Interaction styles, Computer graphics, Methodology and techniques, Interaction
techniques, Design, Experimentation, Human factors, Measurement, Theory,
Gesture input, Input devices, Integrality, Interaction techniques, Perceptual
space, Polhemus tracker, Separability | |||
| Split Menus: Effectively Using Selection Frequency to Organize Menus | | BIBAK | PDF | 27-51 | |
| Andrew Sears; Ben Shneiderman | |||
| When some items in a menu are selected more frequently than others, as is
often the case, designers or individual users may be able to speed performance
and improve preference ratings by placing several high-frequency items at the
top of the menu. Design guidelines for split menus were developed and applied.
Split menus were implemented and tested in two in situ usability studies and a
controlled experiment. In the usability studies performance times were reduced
by 17 to 58% depending on the site and menus. In the controlled experiment
split menus were significantly faster than alphabetic menus and yielded
significantly higher subjective preferences. A possible resolution to the
continuing debate among cognitive theorists about predicting menu selection
times is offered. We conjecture and offer evidence that, at least when
selecting items from pull-down menus, a logarithmic model applies to familiar
(high-frequency) items, and a linear model to unfamiliar (low-frequency) items. Keywords: Information interfaces and presentation, User interfaces, Design, Human
factors, Human-computer interaction, Menus, Selection frequency, Split menus,
User interface | |||
| Organizational Obstacles to Interface Design and Development: Two Participant-Observer Studies | | BIBAK | PDF | 52-80 | |
| Steven E. Poltrock; Jonathan Grudin | |||
| The development of human-computer interfaces was studied in two large
software product development organizations. Researchers joined development
projects for approximately one month and participated in interface design while
concurrently interviewing other project participants and employees, recording
activity in meetings and on electronic networks, and otherwise observing the
process. The two organizations differed in their approaches to development,
and, in each case, the approach differed in practice from the model supported
by the organizational structure. Development practices blocked the successful
application of accepted principles of interface design. The obstacles to
effective design included the inability of interface designers to obtain access
to users, prototyping tools that allow minor changes to be tested but that
constrain innovation, resistance to iterative design that results from people
noticing and being affected by interface changes, and a lack of communication
among those sharing responsibility for different aspects of the interface. Keywords: Software engineering, Tools and techniques, User interfaces, Software
engineering, Design, Methodologies, Software engineering, Miscellaneous, Rapid
prototyping, Models and principles, User/machine systems, Human factors,
Information interfaces and presentation, User interfaces, Theory and methods,
Training, help, and documentation, Design, Human factors | |||
| The Rendezvous Architecture and Language for Constructing Multiuser Applications | | BIBAK | PDF | 81-125 | |
| Ralph D. Hill; Tom Brinck; Steven L. Rohall; John F. Patterson; Wayne Wilner | |||
| When people have meetings or discussions, frequently they use conversational
props: physical models, drawings, or other concrete representations of
information used to enhance the exchange of information. If the participants
are geographically separated, it is difficult to make effective use of props
since each physical prop can only exist in one place. Computer applications
that allow two or more users to simultaneously view and manipulate the same
data can be used to augment human-to-human telecommunication. We have built
the Rendezvous system to aid the construction of applications that can be used
as conversational props. The Rendezvous system is similar to many UIMSs or
user interface toolkits in that it is intended to simplify the construction of
graphical direct-manipulation interfaces. It goes beyond these systems by
adding functionality to support the construction of multiuser applications.
Based on experience with several large applications built with the Rendezvous
system, we believe that it is useful for building conversational props and
other computer-supported cooperative work (CSCW) applications. We present a
list of required features of conversational props, some example applications
built with the Rendezvous system, and a description of the Rendezvous system. Keywords: Programming languages, Language constructs and features, Operating systems,
Organization and design, Interactive systems, Information interfaces and
presentation, User interfaces, User interface management systems, Information
interfaces and presentation, Group and organization interfaces, Synchronous
interaction, Computer graphics, Graphics systems, Languages, Constraint
maintenance, CSCW, Synchronous groupware, UIMS | |||
| A Review and Taxonomy of Distortion-Oriented Presentation Techniques | | BIBAK | PDF | 126-160 | |
| Y. K. Leung; M. D. Apperley | |||
| One of the common problems associated with large computer-based information
systems is the relatively small window through which an information space can
be viewed. Increasing interest in recent years has been focused on the
development of distortion-oriented presentation techniques to address this
problem. However, the growing number of new terminologies and techniques
developed have caused considerable confusion to the graphical user interface
designer, consequently making the comparison of these presentation techniques
and generalization of empirical results of experiments with them very
difficult, if not impossible. This article provides a taxonomy of
distortion-oriented techniques which demonstrates clearly their underlying
relationships. A unified theory is presented to reveal their roots and
origins. Issues relating to the implementation and performance of these
techniques are also discussed. Keywords: Information interfaces and presentations, User interfaces, Human factors,
Bifocal displays, Distortion-oriented presentation, Fisheye views, Focus +
context techniques, Graphical interfaces, Information visualization,
Perspective Wall, Presentation techniques | |||
| Integrating Pointer Variables into One-Way Constraint Models | | BIBAK | PDF | 161-213 | |
| Brad Vander Zanden; Brad A. Myers; Dario A. Giuse; Pedro Szekely | |||
| Pointer variables have long been considered useful for constructing and
manipulating data structures in traditional programming languages. This
article discusses how pointer variables can be integrated into one-way
constraint models and indicates how these constraints can be usefully employed
in user interfaces. Pointer variables allow constraints to model a wide array
of dynamic application behavior, simplify the implementation of structured
objects and demonstrational systems, and improve the storage and efficiency of
constraint-based applications. This article presents two incremental
algorithms -- one lazy and one eager -- for solving constraints with pointer
variables. Both algorithms are capable of handling (1) arbitrary systems of
one-way constraints, including constraints that involve cycles, and (2) editing
models that allow multiple changes between calls to the constraint solver.
These algorithms are fault tolerant in that they can handle and recover
gracefully from formulas that crash due to programmer error. Constraints that
use pointer variables have been implemented in a comprehensive user interface
toolkit, Garnet, and our experience with applications written in Garnet have
proven the usefulness of pointer variable constraints. Many large-scale
applications have been implemented using these constraints. Keywords: Software engineering, Tools and techniques, User interfaces, Software
engineering, Coding, Program editors, Software engineering, Programming
environments, Computing methodologies, Algorithms, Non-algebraic algorithms,
Computing methodologies, Languages and systems, Evaluation strategies,
Algorithms, Design, Languages, Constraints, Development tools, Garnet,
Incremental algorithms | |||
| Toward Visual Debugging: Integrating Algorithm Animation Capabilities within a Source-Level Debugger | | BIBAK | PDF | 215-244 | |
| Sougata Mukherjea; John T. Stasko | |||
| Much of the recent research in software visualization has been polarized
toward two opposite domains. In one domain that we call data structure and
program visualization, low-level canonical views of program structures are
generated automatically. These types of views, which do not require programmer
input or intervention, can be useful for testing and debugging software.
Often, however, their generic, low-level views are not expressive enough to
convey adequately how a program functions. In the second domain called
algorithm animation, designers handicraft abstract, application-specific views
that are useful for program understanding and teaching. Unfortunately, since
algorithm animation development typically requires time-consuming design with a
graphics package, it will not be used for debugging, where timeliness is a
necessity. However, we speculate that the application-specific nature of
algorithm animation views could be a valuable debugging aid for software
developers as well, if only the views could be easy and rapid to create. We
have developed a system called Lens that occupies a unique niche between the
two domains discussed above and explores the capabilities that such a system
may offer. Lens allows programmers to build rapidly (in minutes) algorithm
animation-style program views without requiring any sophisticated graphics
knowledge and without using textual coding. Lens also is integrated with a
system debugger to promote iterative design and exploration. Keywords: Software engineering, Tools and techniques, User interfaces, Software
engineering, Testing and debugging, Debugging aids, Information interfaces and
presentation, User interfaces, Computer graphics, Applications, Simulation and
modeling, Types of simulation, Animation, Algorithms, Human factors,
Verification, Algorithm animation, Debugging, Programming environments,
Software visualization, User interfaces | |||
| What Do Groups Need? A Proposed Set of Generic Groupware Requirements | | BIBA | PDF | 245-268 | |
| Munir Mandviwalla; Lorne Olfman | |||
| Current groupware systems do not fully match the work life of organizational work groups. A multidisciplinary literature analysis was conducted to identify important work group characteristics. This article proposes a set of generic groupware design requirements based on this analysis. These requirements include the need to support multiple tasks and work methods, group development, interchangeable interaction, multiple behaviors, permeable boundaries, and context. Examples of commercial and research groupware systems illustrate the practical implementation issues of each requirement. We conclude that developers need to invent interoperable groupware that provides interchangeable and customizable features through new design metaphors and database structures.Software engineering, Requirements/specifications methodologies, Models and principles, User/machine systems, Human factors, Information system applications, Office automation, Time management, Information system applications, Types of systems, Decision support, Information system applications, Communication applications, Bulletin boards, Computer conferencing and teleconferencing, Electronic mail, Information interfaces and presentation, Group and organization interfaces, Design, Human factors, Theory, Collaboration, Collaborative work, Computer-supported cooperative work (CSCW), Group decision support systems (GDSS), Group support systems (GSS), Groupware | |||
| A Selective Undo Mechanism for Graphical User Interfaces Based on Command Objects | | BIBAK | PDF | 269-294 | |
| Thomas Berlage | |||
| It is important to provide a recovery operation for applications with a
graphical user interface. A restricted linear undo mechanism can conveniently
be implemented using object-oriented techniques. Although linear undo provides
an arbitrarily long history, it is not possible to undo isolated commands from
the history without undoing all following commands. Various undo models have
been proposed to overcome this limitation, but they all ignore the problem that
in graphical user interfaces a previous user action might not have a sensible
interpretation in another state.
Selective undo introduced here can undo isolated commands by copying them into the current state "if that is meaningful." Furthermore, the semantics of selective undo are argued to be more natural for the user, because the mechanism only looks at the command to undo and the current state and does not depend on the history in between. The user interface for selective undo can also be implemented generically. Such a generic implementation is able to provide a consistent recovery mechanism in arbitrary applications. Keywords: Programming techniques, Object-oriented programming, Software engineering,
Tools and techniques, Software libraries, User interfaces, Software
engineering, Miscellaneous, Reusable software, Models and principles,
User/machine systems, Human factors, Information interfaces and presentation,
User interfaces, Interaction styles, User interface management systems,
Information interfaces and presentation, Group and organization interfaces,
Synchronous interaction, Computer graphics, Methodology and techniques,
Interaction techniques, Design, Human factors, Command objects, Groupware, Undo | |||
| A Framework for Undoing Actions in Collaborative Systems | | BIBAK | PDF | 295-330 | |
| Atul Prakash; Michael J. Knister | |||
| The ability to undo operations is a standard feature in most single-user
interactive applications. We propose a general framework for implementing undo
in collaborative systems. The framework allows users to reverse their own
changes individually, taking into account the possibility of conflicts between
different users' operations that may prevent an undo. The proposed framework
has been incorporated into DistEdit, a toolkit for building group text editors.
Based on our experience with DistEdit's undo facilities, we discuss several
issues that need to be taken into account in using the framework, in order to
ensure that a reasonable undo behavior is provided to users. We show that the
framework is also applicable to single-user systems, since the operations to
undo can be selected not just on the basis of who performed them, but by any
appropriate criterion, such as the document region in which the operations
occurred or the time interval in which the operations were carried out. Keywords: Software engineering, Tools and techniques, User interfaces, Models and
principles, User/machine systems, Human factors, Database management, Physical
design, Recovery and restart, Database management, Systems, Concurrency,
Information interfaces and presentation, User interfaces, Theory and methods,
Information interfaces presentation, Group and organization interfaces,
Algorithms, Design, Human factors, Computer-supported cooperative work,
Concurrency control, DistEdit, Groupware, Selective undo, State recovery, Undo,
User recovery | |||
| Reaching for Objects in VR Displays: Lag and Frame Rate | | BIBAK | PDF | 331-356 | |
| Colin Ware; Ravin Balakrishnan | |||
| This article reports the results from three experimental studies of reaching
behavior in a head-coupled stereo display system with a hand-tracking subsystem
for object selection. It is found that lag in the head-tracking system is
relatively unimportant in predicting performance, whereas lag in the
hand-tracking system is critical. The effect of hand lag can be modeled by
means of a variation on Fitts' Law with the measured system lag introduced as a
multiplicative variable to the Fitts' Law index of difficulty. This means that
relatively small lags can cause considerable degradation in performance if the
targets are small. Another finding is that errors are higher for movement in
and out of the screen, as compared to movements in the plane of the screen, and
there is a small (10%) time penalty for movement in the Z direction in all
three experiments. Low frame rates cause a degradation in performance;
however, this can be attributed to the lag which is caused by low frame rates,
particularly if double buffering is used combined with early sampling of the
hand-tracking device. Keywords: Computer graphics, Methodology and techniques, Interaction techniques, Human
factors, Fitts' Law, Haptics, Virtual reality | |||
| HyperActive: Extending an Open Hypermedia Architecture to Support Agency | | BIBAK | PDF | 357-382 | |
| J. Alfredo Sanchez; John J. Leggett; John L. Schnase | |||
| Agency and hypermedia have both been suggested as powerful means to cope
with future information management and human-computer interaction requirements.
However, research projects have included interface agents only marginally in
the context of hypermedia systems. This article proposes a set of criteria for
characterizing interface agents and offers a perspective view of ongoing
research in the field using those criteria as a framework. The need to provide
a supporting infrastructure that facilitates testing and experimentation of
interface agents is stressed. The article describes an existing open
hypermedia architecture and introduces an extended architecture that includes
provisions to support the development and operation of interface agents. A
prototype instantiating this system architecture is presented, as well as an
initial assessment of the potential and requirements of interface agents in a
hypermedia environment. Keywords: Information interfaces and presentation, User interfaces, Interaction
styles, Design, Agent-aware hyperbases, HyperActive, Interface agents, Open
hypermedia systems | |||