| Animated Demonstrations for Exploratory Learners | | BIBAK | 3-22 | |
| Stephen J. Payne; Louise Chesworth; Elaine Hill | |||
| In an animated demonstration the device's display behaves as if the device
were in use. We investigate the instructional potential of a 'pure' version of
animated demonstrations, in which there is no commentary or supporting
documentation for the animation. Such animations are heavily used in video
games (such as PacMan), but are rarely seen in computer-based office systems,
although modern designs allow them to be readily and meaningfully implemented.
We report two experiments that test the efficacy of animated demonstrations as an aid to exploratory learning of the MacDraw graphics editor. The animated demonstration is simulated by playing a short, uncommented, silent video recording of the screen-in-use. Experiment 1 shows that this technique offers large learning advantages over a no-instruction condition, and is, in our limited experiment, as effective as text-based instruction. Experiment 2 replicates the main effect of Experiment 1, again revealing a significant positive effect of a short animated demonstration on first-time exploratory learners. A notable feature of uncommented animation demonstrations is that they do not offer a complete method specification for the performance of any tasks. In the face of this limitation, their success as instructions can perhaps best be understood in terms of psychological models of performance that do not demand complete cognitive encoding of plans or methods. Keywords: Human-computer interaction, Animation, Instruction, Graphics editors | |||
| Motivation, Practice and Guidelines for 'Undoing' | | BIBAK | 23-40 | |
| Yiya Yang | |||
| An 'undo' capability is an interactive recovery facility provided by
interfaces to enable users to reverse the effects of previously issued
commands. The paper reviews the motivation offered in the literature for
having such a facility; surveys existing practice in providing such a facility
and formulates a set of guidelines based on a user-oriented research project to
assist future practice in designing an undo capability for interfaces. Keywords: Human-computer interaction, Interfaces, Undo support, Recovery, Interaction
errors | |||
| Combining CSCW and User Support Techniques to Design Collaborative User Interfaces | | BIBAK | 41-67 | |
| Riitta Hellman | |||
| This paper is concerned with the complexities of collaboration and
collaborative relations in organizations. Examples of coordinating
communications are provided, and a case organization (case study) exemplifying
the complexities of these communications is presented. It is argued that such
complexities can be accommodated within computer-based systems, and some
example user interfaces, based on the case organization and implemented in
HyperCard, are presented to illustrate this point. The first example is of
electronic information media; the second a working role description; while the
third provides an illustration of physical workspace. In connection with
these, a visual orientation vehicle for the example environment is sketched,
and general structures for the design of such interfaces are provided. It is
suggested that these types of interface can enhance existing forms of
computer-mediated collaboration, as well as create new kinds of collaborative
opportunity. Lastly, existing computer-supported cooperative work technologies
are discussed as additional forms of user support that might be of use in the
particular environment of the case organization. Keywords: Human-computer interaction, Computer-supported cooperative work, User
interface, Context support, HyperCard | |||
| Branching Selection of Suggestions | | BIBAK | 68-82 | |
| Joris Verrips | |||
| An on-screen editor has been developed that offers syntactically correct
suggestions for words after the user has entered only the first letter.
Branching selection operates on these suggestions to pick the correct word by
using a specialized form of incremental matching. Part of the user interface;
its evaluation; an essential part of its implementation; and an example of how
the editor can be used are all offered by the paper. Keywords: Human-computer interaction, Screen editor, Interface, Incremental matching | |||
| Formal Interactive Menu Design | | BIBAK | 83-101 | |
| Jacob Ukelson; Johann Makowsky | |||
| In this paper a formal model of menus for interactive systems is defined.
The definition of such a formal model is an important addition to the
engineering concepts that are generally stressed in papers dealing with user
interfaces. The paper takes the simple concept of a menu and defines a
mathematical model which allows rigorous mathematical handling of the concepts
of menus, menu items and menu constructs. Even for such a simple and
well-known concept in user interfaces, such rigorous handling is missing in
much of the literature concerning user interfaces. As shown in the paper, the
mathematical modelling of menus, while mathematically simple, allows insights
into menu definition.
The formal model allows the definition of a new concept of completeness which describes some minimum basic requirements for any menu design language. Based on this definition it is shown that certain menu constructs discussed in the literature do not explicitly meet these basic requirements and therefore may have limited value as building blocks for menu design. The model also provides dialogue designers with well defined terminology which allows simple definitions of the terms persistent menus, transient menus and user context. It also combines the benefits of other menu definition languages in the literature, and avoids their drawbacks. Finally, a menu design system based on these concepts is presented which allows easy definition of menu systems and their logic. Keywords: Human-computer interaction, User interface, Menu design, Dialogues | |||
| The Role of Task Analysis in Systems Design | | BIBAK | 102-123 | |
| David Benyon | |||
| Task analysis and systems analysis are both collections of techniques aimed
at the development of interactive computer-based systems. Clearly there must
be some relationship between them. However, since the techniques originate
from different disciplines, practitioners in one area are not always clear
about that has gone before in the other area. The paper addresses this
problem.
Task analysis clearly has an important role to play in various aspects of systems development. However it may also introduce bad practices which can be avoided if lessons are learnt from the experiences of systems analysis over the last two decades. An understanding of the strengths and weaknesses of systems analysis techniques enables the proper role of task analysis to be understood. Keywords: Human-computer interaction, Systems analysis, Task analysis | |||
| Task Analysis and Systems Analysis for Software Development | | BIBAK | 124-139 | |
| Dan Diaper; Mark Addison | |||
| The paper offers a commentary on Benyon (1992). It questions the absence of
a role for task analysis in the early stages of system development and attempts
to refute many of Benyon's assumptions and criticisms concerning task analysis
methods, at least by showing that his criticisms do not apply to all of them.
The commentary also questions Benyon's systems analysis model for software
development and suggests that it is unrealistic. Keywords: Human-computer interaction, Task analysis, Systems analysis, Software
development | |||
| TripleSpace: An Experiment in a 3D Graphical Interface to a Binary Relational Database | | BIBAK | 147-162 | |
| John A. Mariani; Robert Lougher | |||
| Novel techniques of data visualization will be required to take full
advantage of the advanced human-computer interaction technology now being
developed as part of the virtual reality movement. In particular, meaningful
three-dimensional representations will be of interest to users wishing to
explore the data topology. An experimental system which offers a
three-dimensional topology is presented in this paper; three sets of data
representing interesting situations are described and viewed through the
system. Keywords: Data visualisation, Cyberspace, 3D graphical interfaces, Binary relational
databases, Browsing | |||
| Microcomputer Version of a Digit Span Test in Clinical Use | | BIBAK | 163-178 | |
| Cristopher C. French; J. Graham Beaumont | |||
| At four clinical sites, 188 psychiatric patients were assessed with both the
standard auditory verbal digit span test and a computerised visual digit span
test requiring manual response. Correlations between the two test forms were
comparable with other similar studies. Subjects obtained higher scores on the
standard version than the computerized version, probably reflecting differences
in the mode of presentation and the mode of response, but this difference was
much less pronounced in those subjects receiving the standard version first
rather than the computerized version first. It is clear that the computerized
test cannot be considered to be psychometrically parallel to the standard WAIS
subtest version, but it may still be of some clinical value. Keywords: Computerized testing, Digit span, Clinical applications | |||
| Further Investigations into the Use of Colour Coding Scales | | BIBAK | 179-199 | |
| R. Flavell; A. Heath | |||
| The use of colour in computer-generated displays is increasingly common.
This paper reports on controlled experiments into the quantitative use of
colour using coding scales. Three experiments are described, investigating
respectively:
* The impact of the number of divisions in a perceptually uniform scale. This
showed that errors increased as the numbers of divisions increased, but maximum information transfer actually occurred with about 10 divisions. * The feasibility of constructing scales with a constant spread of incorrect responses for any given stimulus. The overall findings were inconclusive although as a by-product it is statistically suggested that errors are exponentially rather than normally distributed. * The impact of a small number of perceptual discontinuities within an otherwise perceptually uniform scale. It was found that observers did not make response errors that crossed the discontinuities, however their error rate between discontinuities increased. Finally some applications are described. Keywords: Colour, Computer-generated displays, Scales | |||
| Shopfloor Attitudes Towards Advanced Manufacturing Technology: The Changing Focus of Industrial Conflict? | | BIBAK | 200-208 | |
| Keith Davids; Robin Martin | |||
| The implementation of advanced manufacturing technology (AMT) in
manufacturing organisations is increasing. In many cases the introduction of
AMT has been associated with conflict between management and workers. This
appears to be due to the potential for AMT to have a de-skilling effect upon
job content and, in some instances, leading to job losses. In reality, fears
concerning both these issues have reduced and consequently there has been a
change away from conflict between management and workers to divisions amongst
shopfloor operators. The paper explores some of the processes involved in this
change within the context of an engineering case study. More specifically, it
is shown that when AMT was introduced into a machining workshop, traditional
conflict between management and operators was soon replaced by negative
feelings between users and non-users of AMT. The implications of industrial
relations suggest the need for more care and attention to the human side of
work organisation when implementing new manufacturing technology. Keywords: Advanced manufacturing technology, Attitudes in the workplace, Industrial
conflict | |||
| Utility and Usability: Research Issues and Development Contexts | | BIBAK | 209-217 | |
| Jonathan Grudin | |||
| It is notoriously difficult to separate the function of interactive software
from its form, to draw a line between software functionality and its
human-computer interface. Nevertheless, two research communities exist in the
USA, one focused on information system functionality and organizational impact,
the other on human-computer dialogues or 'user interfaces' to systems and
applications. These communities largely draw from different systems
development contexts: in-house or internal development and off-the-shelf
product development, respectively. Each has its own core set of issues,
theoretical constructs, and terminologies. The histories of these research and
development communities are summarized, points of contact are identified, and
their possible evolution is suggested. Keywords: Human-computer interaction, Interfaces, Software functionality | |||
| Field Testing a Natural-Language Information System: Usage Characteristics and Users' Comments | | BIBAK | 218-230 | |
| Andrew S. Patrick; Thomas E. Whalen | |||
| A field trial was conducted to test a natural-language technology developed
by the authors (COMODA) and to dispense AIDS information to the public. This
trial allowed users with computers and modems to dial-in to an AIDS information
system and ask questions or browse through the information. The system
received nearly 500 calls during a two month period. The calls lasted an
average of 10 minutes and involved an average of 27 interactions between the
user and the computer. Approximately 45% of the interactions were direct
natural-language questions, and the COMODA system was quite successful in
answering these questions. Also, the comments left by the users were extremely
positive, with 96% of the users who rated the system giving it a positive
rating. The users commented that the COMODA system was an easy-to-use method
of accessing valuable AIDS information, and they would like to see the system
expanded to cover more topic areas. The users also made useful suggestions on
how the system could be improved. It was concluded that the COMODA system is a
viable natural-language access system for presenting information to the public. Keywords: Human-computer interaction, Natural language processing, Information system | |||
| Display Elements and Gaps: A Comparison of Flat Panel Display Characteristics | | BIBAK | 231-245 | |
| G. P. J. Spenkelink; J. Besuijen | |||
| The relation between typical flat panel display characteristics and display
quality was studied. Subjective preferences were obtained with respect to
simulated black-on-white flat panel displays. The displays differed in the
sort of separation between the display elements and the shape of these
elements. Further, the height/width ratio of the front was studied in relation
with a fixed font matrix. The preferences were obtained through a paired
comparison of all possible pairs of simulated displays.
The observers appeared to be sensitive and to respond to differences in the stimuli. It is not clear, however, if they responded to the type of gap and shape of display elements or to the luminance modulation, which co-varied with the two experimental factors. It can be concluded however that the integrity of the character area is important to the observers. Further, the usefulness of interactively designing spatial display characteristics and the font is discussed. Keywords: Display quality, Flat panel displays, Display standards, Design rules,
Simulation Note: Errata for page 235 (Figures 2a and 2b were transposed) in IwC 4:3, p. 400. | |||
| Task Analysis and System Design: The Discipline of Data | | BIB | 246-259 | |
| David Benyon | |||
| Computer-Based Task Representation: A Methodology for Improving System Design | | BIBAK | 267-288 | |
| David Payne; Maxine Cohen; Richard Pastore | |||
| Task analysis procedures can be used in all stages of system development to
examine the nature and severity of performance demands placed upon human
operators. Task analyses involve considerable effort in obtaining a detailed
set of measurements that represent the behavioural and cognitive tasks
performed by the operators; these measures are referred to as task
representation. The present article describes a flexible method for
incorporating task representation data into an electronic spreadsheet. Such a
computer-based procedure has many advantages over the more traditional paper
and pencil approaches to task representation and analysis, including greater
flexibility in data analysis and the inclusion of both objective and subjective
measures of workload. Portions of an illustrative task representation and task
analysis are presented along with a discussion of the strengths of
computer-based task representation and analysis. Keywords: Human-computer interaction, Task analysis, User interfaces, Task
representation | |||
| How Should Fitts' Law be Applied to Human-Computer Interaction? | | BIBAK | 289-313 | |
| Douglas J. Gillan; Kritina Holden; Susan Adam; Marianne Rudisill; Laura Magee | |||
| The paper challenges the notion that any Fitts' Law model can be applied
generally to human computer interaction, and proposes instead that applying
Fitts' Law requires knowledge of the users' sequence of movements, direction of
movement, and typical movement amplitudes as well as target sizes. Two
experiments examined a text selection task with sequences of controlled
movements (point-click and point-drag). For the point-click sequence, a Fitts'
Law model that used the diagonal across the text object in the direction of
pointing (rather than the horizontal extent of the text object) as the target
size provided the best fit for the pointing time data, whereas for the
point-drag sequence, a Fitts' Law model that used the vertical size of the text
object as the target size gave the best fit. Dragging times were fitted well
by Fitts' Law models that used either the vertical or horizontal size of the
terminal character in the text object. Additional results of note were that
pointing in the point-click sequence was consistently faster than in the
point-drag sequence, and that pointing in either sequence was consistently
faster than dragging. The discussion centres around the need to define task
characteristics before applying Fitts' Law to an interface design or analysis,
analyses of pointing and of dragging, and implications for interface design. Keywords: Human-computer interaction, Fitts' Law, Text editing, Interface design | |||
| Computer Support for Co-Operative Work | | BIB | 314-316 | |
| Tom Rodden; Dianne Murray | |||
| Giving Undo Attention | | BIBAK | 317-342 | |
| Gregory D. Abowd; Alan J. Dix | |||
| The problems associated with the provision of an undo support facility in
the context of a synchronous shared or group editor are investigated. Previous
work on the development of formal models of 'undo' has been restricted to
single user systems and has focused on the functionality of undo, as opposed to
discussing the support that users require from any error recovery facility.
Motivated by new issues that arise in the context of computer supported
co-operative work, the authors aim to integrate formal modelling of undo with
an analysis of how users understand undo facilities. Together, these combined
perspectives of the system and user lead to concrete design advice for
implementing an undo facility. The special issues that arise in the context of
shared undo also shed light on the emphasis that should be placed on single
user undo. In particular, the authors regard undo not as a system command to
be implemented, but as a user intention to be supported by the system. Keywords: Human-computer interaction, Undo support, Computer-supported co-operative
work, Formal methods | |||
| Locating Systems at Work: Implications for the Development of Active Badge Applications | | BIBAK | 343-363 | |
| R. H. R. Harper; M. G. Lamming; W. M. Newman | |||
| The paper reports findings from a sociological examination of the use of
'active badge' location information systems in two research laboratories. The
use, distribution and control of location information is examined in reference
to the social roles individuals have in what will be called the 'moral order'
of workplaces. Suggestions for subsequent versions of location systems are
made, and the use of sociological methods in design remarked. Keywords: Human-computer interaction, Active badges, Location devices, Sociology | |||
| Human and Technical Factors of Distributed Group Drawing Tools | | BIBAK | 364-392 | |
| Saul Greenberg; Mark Roseman; Dave Webster; Ralph Bohnet | |||
| Groupware designers are now developing multi-user equivalents of popular
paint and draw applications. Their job is not an easy one. First, human
factors issues peculiar to group interaction appear that, if ignored, seriously
limit the usability of the group tool. Second, implementation is fraught with
considerable technical hurdles. This paper describes the human and technical
factors that have been met and handled by researchers and implementors of group
drawing tools. We emphasize our own experiences building four systems
supporting remote real time group interaction: GroupSketch and XGroupSketch,
both multi-user sketchpads; GroupDraw, a prototype object-based multi-user
drawing package, and GroupKit, a groupware toolkit. On the human factors side,
we summarize empirically-derived design principles that we believe are critical
to building useful and usable collaborative drawing tools. On the
implementation side, we describe our experiences with replicated versus
centralized architectures, schemes for participant registration, multiple
cursors, network requirements, and the structure of the drawing primitives. A
brief survey of other approaches to group drawing is also included. Keywords: Human-computer interaction, Group drawing, Shared workspace, Real-time
remote conferencing, Computer-supported cooperative work, Groupware | |||