| Usable Software and Its Attributes: A Synthesis of Software Quality, European Community Law and Human-Computer Interaction | | BIBAK | 3-21 | |
| Ronan Fitzpatrick; Catherine Higgins | |||
| Strategic managers and IS professionals who are responsible for specifying,
acquiring and producing quality software products are not supported by the
endless flow of new international standards, legislation and user requirements.
In order to clarify the current situation for everybody concerned with software
quality, and especially those interested in usability, there is a need for a
new review and evaluation of the various strands that contribute to software
quality. By way of review this paper recalls the original software quality
factors which were defined twenty years ago by McCall et al. (1977) and
presents a methodical analysis and synthesis of three modern strands which
influence these factors. The three strands relate to software quality,
statutory obligations and human-computer interaction. All three strands rely
on well respected sources which include the European Council Directive on
minimum safety and health requirements for work with display screen equipment
(Council Directive, 1990), ISO 9241-10 (ISO, 1993) and ISO 9000-3 (ISO, 1997).
This synthesis produces a new set of quality factors, and the paper provides a
new perspective of software usability by showing that the external quality
factors in this new set are the usability attributes of a software product.
New attributes like suitability, adaptability, functionality, installability
and safety are identified and other attributes like usability and integrity are
clarified within the three strands. Keywords: Software quality, European law, International standards, Quality factors,
Usability, Usability models, Usability attributes | |||
| Analysis of Problems Found in User Testing Using an Approximate Model of User Action | | BIBAK | 23-35 | |
| Wai On Lee | |||
| This paper describes an analysis of user testing using an approximate model
that separates user action into Goal Formation, Action Specification, and
Action Execution. It was found that the majority of the problems found in user
testing, as reported within 30 usability reports, were within the Action
Specification phase of user action. In particular, problems in finding an
action or object and in understanding names used were most prevalent. The
implication is that user testing as carried out in an industrial setting might
be beneficial to easing Action Specification whilst neglecting potential
problems in other phases of user action. Keywords: Iterative design, User testing, Usability reports, Approximate phases of
user action | |||
| Software Support for Usability Measurement: An Application to Systems Engineering Data Exchange Development | | BIBAK | 37-52 | |
| James Britton; Linda Candy; Ernest Edmonds | |||
| The goal of ensuring that usability measurement results can contribute to
the ongoing development of a software product in a formative way is, in
practice, difficult to achieve. The paper presents an innovative approach to
supporting that process exemplified in SEDRES, a large European Aerospace
collaborative project on developing a data exchange capability for systems
engineering design tools. The main subject is the role of a software tool
called NUD*IST (Non-numerical Unstructured Data Indexing Searching and
Theorizing), in providing a method for longitudinal data collection and
analysis and support for feedback to the project partners about the product
under development. It describes the analysis techniques employed, the main
features and operational use, followed by examples of results that can be
obtained. The implications of the use of this tool for both the analysis
process and support for formative evaluation are discussed and recommendations
for improvements made. Keywords: Usability, Qualitative data analysis, NUD*IST, Context of use, Evaluation,
Systems engineering, Data exchange | |||
| The Persona Effect: How Substantial Is It? | | BIBAK | 53-66 | |
| Susanne van Mulken; Elisabeth Andre; Jochen Muller | |||
| Personification of interface agents has been speculated to have several
advantages, such as a positive effect on agent credibility and on the
perception of learning experience. However, important questions less often
addressed so far are what effect personification has on more objective
measures, such as comprehension and recall, and furthermore, under what
circumstances this effect (if any) occurs. We performed an empirical study
with adult participants to examine the effect of the Ppp Persona not only on
subjective but also on objective measures. In addition, we tested it both with
technical and non-technical domain information. The results of the study
indicate that the data from the subjective measures support the so called
persona effect for the technical information but not for non-technical
information. With regard to the objective measures, however, neither a
positive nor a negative effect could be found. Implications for software
development are discussed. Keywords: Personified interface agents, Persona effect, Empirical evaluation | |||
| The Influence of Target Size, Distance and Direction on the Design of Selection Strategies | | BIBAK | 67-82 | |
| Xiangshi Ren; Shinji Moriya | |||
| The influence of various parameters on the design of selection strategies
was investigated. Our question is, do changes in the size, distance or
direction to a target affect the differences in performance between selection
strategies? We performed an experiment on a pen-based system to evaluate the
effect of size, distance and direction on six strategies for selecting a
target. Three target sizes, three pen-movement-distances, and eight
pen-movement-directions were applied to all six strategies. The results show
that the differences between selection strategies are affected by target size
(when target size decreases below a certain size, differences between selection
strategies appear; conversely, differences between selection strategies
disappear when target sizes are increased beyond a certain size). The results
also show that the differences between selection strategies are not affected by
pen-movement-distance and pen-movement-direction. Issues relating to the
merits of individual strategies will be the focus of planned future
investigations. Keywords: Mobile computing, Pen-based systems, Pen-input interfaces, Target selection
strategies, Small targets, Variations in differences | |||
| A Study of Two Keyboard Aids to Accessibility | | BIBAK | 83-97 | |
| Shari Trewin; Helen Pain | |||
| Sticky Keys and Repeat Keys are two important keyboard configuration
facilities intended to improve keyboard access for users with motor
disabilities. While the value of such facilities has long been recognized,
there has been very little empirical research examining their use.
This paper reports on a study in which both facilities were found to be effective in eliminating certain input errors. While Repeat Keys did not introduce any difficulties in the tasks studied, some important difficulties with Sticky Keys were observed. Suggestions for modifications to Sticky Keys which may reduce users' difficulties are made. Keywords: Disability access, Keyboard configuration, Sticky keys, Repeat keys, Motor
disabilities, Empirical studies of users | |||
| Combining Goals and Functional Requirements in a Scenario-Based Design Process | | BIBAK | 101-121 | |
| Hermann Kaindl | |||
| While promising approaches to early system design using scenarios have been
proposed, no design process is available that guides scenario-based
development. We present a model that combines scenarios both with functions
and goals. Functions are required to make the desired behaviour of some
scenario happen in order to achieve one or more goals. Using this model, we
propose a systematic and concrete design process that is both model-driven and
data-driven. Our design process supports the transition from the current to a
new system and guides the design of a new system. In addition, this process
makes it possible to detect redundancy and to improve both completeness and
understandability of the resulting design. We have applied our approach in
real-world projects, and our experience suggests the utility of this approach. Keywords: Scenarios, Design techniques | |||
| Understanding a Task Model: An Experiment | | BIBAK | 123-137 | |
| Nadine Ozkan; Cecile Paris; Sandrine Balbo | |||
| The HCI community advocates task analysis as a useful technique for user
requirements analysis and system design, and has shown that task models should
be developed collaboratively with users. The question of the usability and
readability of task models for end-users is therefore an important one. In
addition, we were specifically interested in this question in the context of
our current project, Isolde (An Integrated Software and On-Line Documentation
Environment). Isolde is an authoring tool for technical writers whose user
interface relies heavily on a specific task notation, DIANE+. We undertook an
empirical study aimed at testing the readability and usability of DIANE+. Two
experimental tasks are performed by end-users with no previous exposure to task
models. Results show that DIANE+ is largely readable but that its usability is
somewhat more problematic. This can be attributed to the task description
notation rather than to the concepts themselves. Keywords: Task analysis, Task modelling, Usability of task models, Empirical study | |||
| Analysing Requirements to Inform Design | | BIBAK | 139-157 | |
| Michele Ryan; Alistair Sutcliffe | |||
| Publications, guidelines and methodologies have proliferated on usability
engineering in the HCI literature while an extensive literature exists on
methods in requirements engineering. Requirements analysis and usability are
inextricably linked yet few methods exist to integrate the two approaches. In
this paper we propose a framework for analysing requirements of systems and
user interfaces, and report its use in requirements capture. Inadequacies
resulting from the application of the framework are described leading to
development of a method for requirements elaboration. Use of the method is
illustrated by applying it retrospectively to the requirements capture
exercise. Keywords: Reuse, Usability, Evaluation, Frameworks, Methods, Requirements gathering | |||
| Generalizing Claims and Reuse of HCI Knowledge | | BIBAK | 159-176 | |
| Alistair Sutcliffe; John Carroll | |||
| A framework for classifying claims and indexing them for reuse with generic
models is proposed. Claims are classified by a schema that includes design
issues, dependencies, usability effects, with links to scenarios and the
artefact associated with the claim. Generic models describe classes of
application and tasks. Claims are associated with appropriate model
components. Models which match a new application are retrieved from a library
by using keyword searches or browsing the model hierarchy. Claims are reused
on applications sharing the same generic application. Artefacts associated
with claims may also be reused although user interfaces need customizing
because of domain specific features. Claims evolution and reuse are
illustrated with an information retrieval case study. Keywords: Knowledge reuse, Task-artefact cycle, Domain models, Claims, Design process | |||
| Detecting and Resolving Temporal Ambiguities in User Interface Specifications | | BIBAK | 177-188 | |
| Paul Chesson; Lorraine Johnston; Philip Dart | |||
| Temporal ambiguities occur in user interface specifications when the
application of multiple requirements can be interpreted in more than one way
depending on when their conditions are evaluated. This paper discusses the
resolution of temporal ambiguities using two approaches. The first approach
involves the writer clarifying the intention of statements in an informal
natural language specification. The second approach involves the use of a
principle of ordered events to guide the writing and rewriting of the
specification to avoid the ambiguity. A method for automatically detecting
such ambiguities is presented, using an abstract specification model based on
the language FLUID. Keywords: User interface, Dialogue specification, Requirements | |||
| The Design of New Technology for Writing On-Line Help | | BIBAK | 189-206 | |
| Cecile Paris; Nadine Ozkan; Flor Bonifacio | |||
| This paper presents an instance of the design of new technology in the
domain of technical writing. We are proposing a novel tool for technical
writers called Isolde (An Integrated Software and On-Line Documentation
Environment). Isolde has the potential to change substantially the technical
writing process as well as the place of technical writers in a software
development team. Consequently, Isolde has been designed through the
collaboration of end-users and human computer interaction specialists. This
paper shows how its design has evolved from technical and user related
considerations, ensuring that Isolde is both feasible and desirable. The paper
also discusses the use and place of this new technology in the technical
writers' work environment. Keywords: Participatory design, Technical writing, Task modelling, Emerging
technology, Requirements analysis, Work practices | |||
| Representation Matters: The Effect of 3D Objects and a Spatial Metaphor in a Graphical User Interface | | BIBAK | 209-219 | |
| Wendy Ark; D. Christopher Dryer; Ted Selker; Shumin Zhai | |||
| As computer graphical user interfaces (GUIs) are loaded with increasingly
greater numbers of objects, researchers in HCI are forced to look for the next
step in constructing user interface. In this paper, we examine the effects of
employing more 'natural' representations in GUIs. In particular, we
experimentally assess the impact of object form (2D iconic versus 3D realistic)
and layout (regular versus ecological) have on target acquisition time.
Results indicate that both form and layout significantly affect performance;
subjects located targets more quickly when using interfaces with 3D objects and
ecological layouts than they do with 2D objects and regular layouts. An
interface with an ecological layout, realistic objects, or both may be an
improvement over traditional interfaces. Keywords: 3D interface, Graphical interface, Spatial metaphor, Icon, Ecological
layout, Regular layout | |||
| The Effect of Layout on Dispatch Planning and Decision Making | | BIBAK | 221-238 | |
| William B. L. Wong; David O'Hare; Philip J. Sallis | |||
| This paper reports on an experiment conducted to determine whether the
manner in which information is portrayed affects ambulance planning and
dispatch decision making performance. Based the outcomes of a series of
cognitive task analysis, deficiencies in an actual ambulance status display
used for dispatch management was identified. The display was then re-designed
by applying cognitive engineering principles to achieve task-to-display
compatibility. The new display was then evaluated and it was found to improve
dispatch decision making performance by 40%. Keywords: Display design, Proximity-compatibility principle, Mental model, Ambulance
dispatch management | |||
| Distortion-Oriented Workspace Awareness in DOME | | BIBAK | 239-252 | |
| Philip Weir; Andy Cockburn | |||
| Distortion-oriented visualization techniques such as magnification-lenses,
zooming functions and fish-eye views are useful in a wide range of single-user
computing systems. They assist visualization of large information spaces by
easing the transition between high-levels of detail in a local area of interest
and the global context of the information space.
In real-time groupware environments, distortion-oriented visualizations offer additional benefits. By providing one distorted region for each user of a groupware workspace, users can maintain an awareness of the location and activities of their colleagues while simultaneously having a focused area of detail for their own work. We describe the design and evaluation of DOME, a fully-functional distortion-oriented multi-user editor. Unexpected usability problems and potential solutions are discussed. Keywords: Groupware, Collaborative workspace awareness, Distortion-oriented
visualization | |||
| Towards Principles for the Design and Evaluation of Multimedia Systems | | BIBAK | 255-271 | |
| Peter Johnson; Fabio Nemetz | |||
| The rapid growth of multimedia technology has made it possible to deliver
high quality audio, graphics, video and animation to the user. However, this
growth in technology has not been met by a growth in design knowledge. While
it is possible to have multimedia it is not at all obvious that we know how to
design high-quality multimedia systems that are fully usable to the degree we
should expect. To improve the situation much work is under way to develop
guidelines, style guides and principles for multimedia design. This paper
illustrates the problem facing designers (and users) of multimedia systems by
examining some of the design mistakes that have been made in one public
information system (as an example of one class of multimedia systems). We then
consider what design features any such principles should address. Keywords: Multimedia system design, Evaluation of multimedia systems, Principles for
multimedia design | |||
| How Can Multimedia Designers Utilize Timbre? | | BIBAK | 273-286 | |
| Dimitrios I. Rigas; James L. Alty | |||
| When musical sound is required during development of auditory or multimedia
interfaces, designers often need to utilize different musical voices or timbre
(usually produced via a multiple timbre synthesizer or a sound card) in order
to communicate information. Currently, there is a limited set of guidelines
assisting multimedia designers to select appropriate timbre. This paper
reports a set of recall and recognition experiments on timbres produced by a
multiple timbre synthesizer. Results indicate that a number of instruments
were successfully recalled and recognized. A set of empirically derived
guidelines are suggested to assist multimedia designers in selecting timbre. Keywords: User interfaces, Multimedia, Auditory, Music, Timbre, Instruments | |||
| Using Earcons to Improve the Usability of a Graphics Package | | BIBAK | 287-302 | |
| Stephen Brewster | |||
| This paper describes how non-speech sounds can be used to improve the
usability of a graphics package. Sound was specifically used to aid problems
with tool palettes and finding the current mouse coordinates when drawing.
Tool palettes have usability problems because users need to see the information
they present but they are often outside the area of visual focus. An
experiment was conducted to investigate the effectiveness of adding sound to
tool palettes. Earcons were used to indicate the current tool and when tool
changes occurred. Results showed a significant reduction in the number of
tasks performed with the wrong tool. Therefore users knew what the current
tool was and did not try to perform tasks with the wrong tool. All of this was
not at the expense of making the interface any more annoying to use. Keywords: Earcons, Sonically-enhanced widgets, Sound, Interface sonification | |||
| A New Concept Touch-Sensitive Display Enabling Vibro-Tactile Feedback | | BIBAK | 303-312 | |
| Masahiko Kawakami; Masaru Mamiya; Tomonori Nishiki; Yoshitaka Tsuji; Akito Okamoto; Toshihiro Fujita | |||
| This paper describes the concept and the characteristics of a newly
developed touch-sensitive display which supports vibro-tactile feedback. This
new touch-sensitive display named 'Vibration Touch' was developed to improve
the uneasy operation of touch-sensitive displays due to lack of tactile
feedback. Vibro-tactile feedback is realized by a combination of solenoid and
spring which is directly attached to touch-sensitive panel. Vibration Touch is
operated by a two-step input operation which enables certain operations and
prevents mis-operation. Keywords: Touch-sensitive display, Vibro-tactile feedback, GUI, LCD, HMI | |||
| Preliminary Investigations into the Use of Wearable Computers | | BIBAK | 313-325 | |
| Chris Baber; David Haniff; Lee Cooper; James Knight; Brian Mellor | |||
| In this paper, we investigate human factors which could have a bearing on
the use of wearable computers. The first study examines performance on a
reaction time task using a head-mounted display in comparison with performance
on a sVGA visual display unit. While the number of missed targets was not
significantly different, there were significant differences in reaction time to
displays. The second study shows performance time of participants using a
wearable computer to be superior to those using paper-based manual and
recording, but there is a trend for more errors to be made when using the
wearable computer. Keywords: Wearable computers, Head-mounted displays, Speech technology | |||
| On the Problems of Validating DesktopVR | | BIBAK | 327-338 | |
| Chris Johnson | |||
| For the last twenty years, human-computer interfaces have been dominated by
two-dimensional interaction techniques. Things are changing. Techniques that
were previously restricted to specialized CAD/CAM tools and immersive VR
systems are now being extended to the mass market. The photo-realistic
facilities offered by QuicktimeVR and the model based renderings of VRML
(Virtual Reality Mark-up Language) provide sophisticated tools for interface
design. As a result, three dimensional visualization techniques are being
widely exploited in the financial services industry, airports and even
off-shore oil production. In January 1997, there were some 2,000 VRML models
on the web. By January 1998, this number had grown to over 20,000. Research
in human-computer interaction has, however, lagged behind these developments.
Few guidelines can be applied to support the design of desktopVR. This paper,
therefore, describes three criteria that can be applied to assess the usability
of these interfaces. We then go on to validate these criteria against a number
of case studies. Unfortunately, it is concluded that standard measures of task
performance, successful navigation and subjective satisfaction cannot easily be
applied to assess the utility of 3D systems. Keywords: DesktopVR, 3D interfaces, VRML, QuicktimeVR | |||