| Making Passwords Secure and Usable | | BIBAK | 1-19 | |
| Anne Adams; Martina Angela Sasse; Peter Lunt | |||
| To date, system research has focused on designing security mechanisms to
protect systems access although their usability has rarely been investigated.
This paper reports a study in which users' perceptions of password mechanisms
were investigated through questionnaires and interviews. Analysis of the
questionnaires shows that many users report problems, linked to the number of
passwords and frequency of password use. In-depth analysis of the interview
data revealed that the degree to which users conform to security mechanisms
depends on their perception of security levels, information sensitivity and
compatibility with work practices. Security mechanisms incompatible with these
perceptions may be circumvented by users and thereby undermine system security
overall. Keywords: Security, Passwords, Grounded theory, Organisational factors | |||
| Strategies for Organising Email | | BIBAK | 21-38 | |
| Olle Balter | |||
| With the increasing flow of email, strategies for organising email messages
become more important. Research describes various strategies used for
archiving and retrieving messages. Categorising these strategies is important
to identify special needs, problems and solutions for users of each strategy.
This study extends earlier categories by grouping users after folder usage and
cleaning frequency. Conclusions are that the strategies are affected by the
choice of mail tool and number of incoming messages, but no influence by the
work task or position could be found. Some advice on interface design to
support the different strategies is given. Keywords: Electronic mail, Email, Organisation, Archiving, Folder, Cleaning, Strategy | |||
| Navigating Telephone-Based Interfaces with Earcons | | BIBAK | 39-56 | |
| Stephen Brewster | |||
| Non-speech audio messages called earcons can provide powerful navigation
cues in menu hierarchies. However, previous research on earcons has not
addressed the particular problems of menus in telephone-based interfaces
(TBI's) such as: Does the lower quality of sound in TBI's lower recall rates,
can users remember earcons over a period of time and what effect does training
type have on recall. An experiment was conducted and results showed that sound
quality did lower the recall of earcons. However, redesign of the earcons
overcame this problem with 73% recalled correctly. Participants could still
recall earcons at this level after a week had passed. Training type also
affected recall. With 'personal training' participants recalled 73% of the
earcons but with purely textual training results were significantly lower.
These results show that earcons can provide excellent navigation cues for
telephone-based interfaces. Keywords: Earcons, Telephone-based interfaces, Auditory interfaces, Non-speech audio,
Navigation | |||
| Do Users Always Benefit When User Interfaces Are Consistent? | | BIBA | 57-66 | |
| David A. Caulton; Ken Dye | |||
| Do users always learn a new program faster if its UI is consistent with a previously learned user interface? Most UI style guides claim they do. A study is described that refutes this claim by demonstrating a case where a version of Microsoft Project that is less consistent with Microsoft Office is more usable to expert Office users than one that is more consistent with Office. It is proposed that the inconsistent version is more usable because Microsoft Project is a different class of application -- more vertical -- and thus different UI techniques are appropriate. It is argued that users benefit from consistent interfaces where programs perform similar functions over a wide range of user goals, but in more vertical applications and where the user's goals are different, appropriateness to purpose is more important than consistency. | |||
| Conceptual Design Reconsidered: The Case of the Internet Session Directory Tool | | BIBAK | 67-84 | |
| Louise Clark; M. Angela Sasse | |||
| We report a case study in which conceptual design was applied to create a
user interface of an innovative software tool. The Session Directory Tool
(sdr) allows users to set up and participate in real-time interactive
multimedia events on the Internet. To make this functionality available to
users who are not familiar with the underlying network technology and
videoconferencing, we identified a metaphor which could be extended into a
design model (Electronic TV Listings Guide), and communicated this model
through linguistic and structural features of the user interface. Evaluation
results indicate that this effort was largely successful: new users handled sdr
competently after a short training session and 5 days' practise, and
articulated their knowledge of the tool in terms related to the design model.
The case study demonstrates the potential of conceptual design, integrated with
tangible HCI design techniques, for developing user interfaces to innovative
technology. Keywords: Conceptual design, Mental models, Users' models, Internet conferencing | |||
| Computer Anxiety and the Human-Computer Interface | | BIBAK | 85-100 | |
| Donald Day; Paivi Makirinne-Crofts | |||
| Despite widespread PC use in recent decades, many users remain anxious about
their ability to cope with computers. This paper reports a study evaluating
how interface features contribute to computer anxiety. Key constructs include
cultural and individual differences, interface quality, self-efficacy, ease of
use, user attitudes and intended usage behaviour. Findings indicate that
anxious users prefer innovative I/O devices, experience low self-efficacy, and
dislike inconsistent status messages and blocked-option menus. Intended usage
behaviour appears to be inversely related to levels of computer anxiety. These
findings provide moderate support for a modified Technology Acceptance Model
proposed by the study. Keywords: Computer anxiety, Interface quality, Self-efficacy | |||
| Towards a Situated Action Calculus for Modelling Interactions | | BIBAK | 101-116 | |
| Alberto Faro; Daniela Giordano | |||
| Formal modelling of situated actions and context is a worthwhile endeavor if
it provides a framework for verifying requirements correctness and generates
principles for building interfaces for fluid interactions. The paper argues
that action sequences, rather than states, are a suitable representation for
this problem, and proposes a situated action calculus based on a new material
implication relation among contexts. The situated action calculus extends in
two respects a story-telling theory for embedding the user requirements in
meaningful contexts. First, it provides a formalism and a set of operators
that allow the designer to verify that stories told by different actors
generate a safe and live representation; and second, it allows partitioning
such representation in a succession of scenes which can be aggregated to define
for each actor an interface that unfolds with the task and the context. Keywords: Situated action calculus, Formal specification, Requirements engineering,
Information systems design | |||
| Explorations in Sonic Browsing | | BIBAK | 117-131 | |
| M. Fernstrom; L. Bannon | |||
| This paper describes a novel browser prototype that has been designed and
implemented on PC's and soundcards. Our focus has been on the development of a
usable and engaging interface which exploits both visual and aural features of
the data space. The project involves state-of-the-art work in human-computer
interaction and multimedia development. We are working on a data set of
musical compositions, and are designing and testing the prototype with a group
of musicians. This paper provides some detail on the development process, the
current architecture of the system, and describes some of the problems
encountered. Keywords: Browsing, Multimedia, Visualisation, Sonification, Spatial audio | |||
| Remote Homeplace Communication: What is It Like and How Might We Support It? | | BIBAK | 133-153 | |
| David M. Frohlich; Kathy Chilton; Paul Drew | |||
| We introduce the study of homeplace communication as being relevant to the
design of new communication technology for the home market. After reviewing
current approaches to the field, we go on to describe the nature of remote
homeplace communication over the telephone, based on a quantitative and
qualitative analysis of 315 household telephone calls. The findings are
contrasted with aspects of workplace communication and used to identify 7 user
requirements for support. We conclude with recommendations for future basic
and applied research in the area. Keywords: Home, Homeplace, Communication, Interaction, Telephone, Call, Relationship,
User needs, Requirements, Technology | |||
| A Making-Movies Metaphor for Structuring Software Components in Highly Interactive Applications | | BIBAK | 155-173 | |
| Michelle Jacomi; Stephane Chatty; Philippe Palanque | |||
| Structuring full scale, highly interactive applications still involve
complex design choices for programmers. This is because current techniques do
not cover the issue of structuring applications at all scales. Programmers
thus have to make choices without a good understanding of their consequences.
We consider that this is similar to the problem encountered by a user who
explores a user-driven application and has little guidance on actions that can
be performed. In the same way as metaphors have been used to help users
anticipate the consequences of their actions, we propose to use metaphors to
help programmers make their choices. This article describes a making-movies
metaphor that provides guidance for organising the interface of an application,
but also its links with the objects of the functional core. We show how this
approach can be merged with current software engineering techniques to specify
and build full scale applications. This is exemplified with a graphical editor
acting as an interface to optimisation algorithms, and used for splitting air
space into air traffic control sectors. Keywords: Software architecture, User interface design, Metaphors | |||
| The Impact of Time and Place on the Operation of Mobile Computing Devices | | BIBAK | 175-190 | |
| Chris Johnson | |||
| Recent improvements in the quality and reliability of wireless
communications has led to the development of a range of mobile computing
devices. Many portable computers now offer modem connections through cellular
and satellite telephone networks. Taxi services, emergency vehicles, domestic
repair teams all now rely upon mobile links to central computing systems. In
spite of these advances, a number of technical problems still affect the
quality of interaction with mobile applications. Electromagnetic interference
blocks radio signals. Obstacles in the line of sight can interrupt microwave
and infra-red transmissions. Tracking problems frustrate the use of low-level
satellites. Transmission delays affect the service provided by higher,
geostationary satellites. From the users' point of view, these problems
manifest themselves as geographical constraints upon the usability of their
'mobile' device. This lead to delays in the transmission of critical
information. These, in turn, lead to the frustration and error that often
complicates the operation of mobile computer systems. In the short term, it
seems unlikely that the technical limitations will be resolved. The following
pages, therefore, argue that interface designers must consider means of
reducing the impact of geographic allocation upon the operation of mobile
computing devices. Keywords: Mobile computing, Interface design, Satellite communications, Cellular
networks | |||
| The Impact of Marginal Utility and Time on Distributed Information Retrieval | | BIBAK | 191-204 | |
| Chris Johnson | |||
| This paper argues that marginal utility can be extended from the domain of
Micro-economics to explain some of the problems that frustrate interaction with
distributed systems. In particular, it is argued that concave utility curves
can be used to analyse the electronic gridlock that occurs when remote systems
cannot satisfy the number of demands which users make upon their services.
Convex utility curves represent the information saturation that occurs when
users cannot extract important documents from amass of irrelevant information.
The paper goes on to argue that marginal utility can also be used to identify a
range of interface techniques that reduce the problems associated with
electronic gridlock and information saturation. Keywords: Electronic gridlock, Information saturation, Marginal utility | |||
| Computer-Assisted Remote Control for the User with Motor Impairment | | BIBAK | 205-221 | |
| Peter E. Jones | |||
| Two projects are described for children with Cerebral Palsy. The first one
is a computer controlled radio car, CAR. This provided the inspiration for the
solution needed in the second project -- a remote control for a user with motor
impairment. This resulted in a prototype controller box that we named Rico.
It is a low cost device attached via the parallel port to any PC. It is
capable of adapting to the infrared signals of most remote controls for
domestic devices such as CD players, TVs and VCRs. Users with severe motor
impairment can interact with a computer and through Rico have it mimic the
action of the domestic remote controls. In first learning to use both CAR and
Rico, we found it necessary to allow simultaneous interaction by the user and
the teacher or occupational therapist. Therefore we have two humans in the
HCI! The user who is motor impaired interacts via any one of a number of
simple selection devices whilst the teacher uses the keyboard. In our case the
users were teenagers severely disabled by Cerebral Palsy, who are confined to
wheelchairs and are at the stage of just learning to read. The adaptability of
the hardware and software would allow the use of Rico for a wide range of users
suffering motor impairment through other causes. Keywords: Assistive technology, Motor impaired, Cerebral palsy, Remote control, Novel
input-output | |||
| Research and the Design of Human-Computer Interactions or 'What Happened to Validation?' | | BIBAK | 223-243 | |
| John Long | |||
| This paper argues the need for more effective: human-computer interactions;
design of such interactions; and research to support such design. More
effective research would result in more effective interactions. One
contribution to more effective research would be the specification of relations
between research and the design of human-computer interactions in support of
the validation of new knowledge. The aim of this paper is to propose such a
specification both for HCI and Cognitive Science research and the relations
between them. Meeting the HCI specification renders HCI knowledge coherent,
complete and 'fit-for-design-purpose'. The paper concludes that specification
of relations is required for more effective research support for the design of
human-computer interactions. Keywords: Research, Design, Human-computer interactions, Effectiveness | |||
| Using Diagrams to Support the Analysis of System 'Failure' and Operator 'Error' | | BIBAK | 245-261 | |
| Lorna Love; Chris Johnson | |||
| Computers are increasingly being embedded within safety systems. As a
result, a number of accidents have been caused by complex interactions between
operator 'error' and system 'failure'. Accident reports help to ensure that
these 'failures' do not threaten other applications. Unfortunately, a number
of usability problems limit the effectiveness of these documents. Each section
is, typically, drafted by a different expert; forensic scientists follow
metallurgists, human factors experts follow meteorologists. In consequence, it
can be difficult for readers to form a coherent account of an accident. This
paper argues that fault trees can be used to present a clear and concise
overview of major failures. Unfortunately, fault trees have a number of
limitations. For instance, they do not represent time. This is significant
because temporal properties have a profound impact upon the course of
human-computer interaction. Similarly, they do not represent the criticality
or severity of a failure. We have, therefore, extended the fault tree notation
to represent traces of interaction during major failures. The resulting
Accident Fault Tree (AFT) diagrams can be used in conjunction with an official
accident report to better visualise the course of an accident. The Clapham
Junction railway disaster is used to illustrate our argument. Keywords: Accident analysis, Fault trees, Operator 'error', System 'failure' | |||
| The Interactional Affordances of Technology: An Ethnography of Human-Computer Interaction in an Ambulance Control Centre | | BIBA | 263-281 | |
| David Martin; John Bowers; David Wastell | |||
| This paper reports an ethnography of ambulance dispatch work in a large UK metropolitan region. The interplay between control centre ecology, usage of a computerised dispatch system, and cooperative work of control personnel is analysed. The methods by which a 'working division of labour' is sustained to effectively manage dispatch in the face of high workload and manifold contingency are explicated, and contrasted with methods employed by workers in other control room settings known from the literature. The implications of the study for system improvement and for several emphases in HCI research (including discussions of 'affordances') are explored. | |||
| Why, What, Where, When: Architectures for Cooperative Work on the World Wide Web | | BIBAK | 283-301 | |
| Devina Ramduny; Alan Dix | |||
| The software architecture of a cooperative user interface determines what
component is placed where. This paper examines some reasons determining why a
particular placement should be chosen. Temporal interface behaviour is a key
issue: when users receive feedback from their own actions and feedthrough about
the actions of others. In a distributed system, data and code may be moved to
achieve the desired behaviour -- in particular, Java applets can be downloaded
to give rapid local semantic feedback. Thus we must choose not only the
physical location for each functional component but also when that component
should reside in different places. Keywords: Software architecture, CSCW, Internet, Caching, Replication, Applets,
Feedback, Feedthrough, Temporal problems, Delays | |||
| BUILD-IT: A Computer Vision-Based Interaction Technique for a Planning Tool | | BIBAK | 303-314 | |
| M. Rauterberg; M. Fjeld; H. Krueger; M. Bichsel; U. Leonhardt; M. Meier | |||
| In this article we wish to show a method that goes beyond the established
approaches of human-computer interaction. We first bring a serious critique of
traditional interface types, showing their major drawbacks and limitations.
Promising alternatives are offered by Virtual (or: immersive) Reality (VR) and
by Augmented Reality (AR). The AR design strategy enables humans to behave in
a nearly natural way. Natural interaction means human actions in the real
world with other humans and/or with real world objects. Guided by the basic
constraints of natural interaction, we derive a set of recommendations for the
next generation of user interfaces: the Natural User Interface (NUI). Our
approach to NUIs is discussed in the form of a general framework followed by a
prototype. The prototype tool builds on video-based interaction, and supports
construction and plant layout. A first empirical evaluation is briefly
presented. Keywords: Augmented reality, Natural user interface, Video based interaction, Computer
aided design | |||
| Formally Comparing and Informing Notation Design | | BIBAK | 315-336 | |
| C. R. Roast | |||
| This paper uses the analytic framework of cognitive dimensions to provide
formal interpretations of dimensions for appraising the suitability of
interactive systems for particular tasks. The framework also provides an
effective terminology to support a wide range of assessments including
interface evaluation, and the resistance of notations to modification. We
propose that interface design can benefit from interpreting cognitive
dimensions as tools for assessing software characteristics such as usability
and modifiability. Our interpretation of these dimensions has the benefits of
being formal and at the same time yielding practical measures and guidelines
for assessment. In this paper our formalisation of cognitive dimensions
examines and illustrates the dimensions of 'viscosity' -- resistance to change.
We demonstrate the appropriateness of the measures developed as a means of
assessing notational resistance to change and the general results that their
formalization enables. Keywords: Cognitive dimensions, Formal methods, Notations, programming | |||
| Direct Object Manipulation vs. Direct Concept Manipulation: Effect of Interface Style on Reflection and Domain Learning | | BIBAK | 337-357 | |
| Kamran Sedighian; Marv Westrom | |||
| This paper investigates the effects of interface style on children's domain
learning and reflective thought. It argues that the educational deficiencies
of Direct Manipulation (DM) interfaces are not necessarily caused by their
"directness", but by their directness towards objects rather than embedded
educational concepts. This paper furthers our understanding of the DM metaphor
in educational software by proposing a shift of approach from Direct Object
Manipulation (DOM) to Direct Concept Manipulation (DCM). A number of
pedagogical strategies for supporting the DCM metaphor are offered. Results
reported from a study using three variations of an educational software
application are used to support these points. Keywords: Interface, Direct manipulation, Reflection, Children, Education, Learning,
Motivation, Mathematics, Problem solving, Human-computer interaction,
Transformation geometry | |||
| HyperAT: HCI and Web Authoring | | BIBAK | 359-378 | |
| Yin Leng Theng; Cecile Rigny; Harold Thimbleby; Matthew Jones | |||
| We review HCI problems with hypertext, and for authoring World Wide Web
documents in particular. We suggest that a framework is required to understand
the usability issues, and that these issues cannot be seen as psychological or
computing: they are multi-disciplinary. We discuss HyperAT, a prototype
authoring tool, being implemented to test these ideas. Keywords: "Lost in hyperspace", Authoring tool, World Wide Web, Multi-disciplinary
approach | |||
| Separating User Knowledge of Domain and Device: A Framework | | BIBAK | 379-395 | |
| Peter Timmer; John Long | |||
| A framework for modelling user-device interaction is presented. Models
constructed with the framework explicitly separate 1) what the operator knows
about the work (domain) being carried out, from 2) what the operator knows
about the state of the devices used to carry out that work. Using an
illustration from Air Traffic Management (ATM), the value of such separation is
shown, for the diagnosis of operator behaviour that leads to system
ineffectiveness. The design implications of using such worksystem models, in
conjunction with domain models, are discussed. Keywords: Mental representation, Domain, Problem diagnosis, Air traffic management | |||
| Eliciting Information Portrayal Requirements: Experiences with the Critical Decision Method | | BIBAK | 397-415 | |
| William B. L. Wong; Philip J. Sallis; David O'Hare | |||
| This study is part of research that is investigating the notion that human
performance in dynamic and intentional decision making environments, such as
ambulance dispatch management, can be improved if information is portrayed in a
manner that supports the decision strategies invoked to achieve the goal states
of the process being controlled. Hence, in designing interfaces to support
real-time dispatch management decisions, it is suggested that it would be
necessary to first discover the goal states and the decision strategies invoked
during the process, and then portray the required information in a manner that
supports such a user group's decision making goals and strategies.
The purpose of this paper is to report on the experiences gleaned from the use of a cognitive task analysis technique called Critical Decision Method as an elicitation technique for determining information portrayal requirements. This paper firstly describes how the technique was used in a study to identify the goal states and decision strategies invoked during the dispatch of ambulances at the Sydney Ambulance Coordination Centre. The paper then describes how the interview data was analysed within and between cases in order to reveal the goal states of the ambulance dispatchers. A brief description of the resulting goal states follows, although a more detailed description of the goals states and their resulting display concepts has been reported elsewhere (Wong et al., 1996b). Finally, the paper concludes with a set of observations and lessons learnt from the use of the Critical Decision Method for developing display design concepts in dynamic intentional environments. Keywords: Display design, Cognitive task analysis, Critical Decision Method, Ambulance
dispatch management | |||