Interacting with Computers

A near ubiquitous feature of user interfaces is feedback on task completion or progress indicators such as the graphical bar that grows as more of the task is completed. The presumed benefit is that users will be more likely to complete the task if they see they are making progress but it is also possible that feedback indicating slow progress may sometimes discourage users from completing the task. This paper describes two experiments that evaluate the impact of progress indicators on the completion of on-line questionnaires. In the first experiment, progress was displayed at different speeds throughout the questionnaire. If the early feedback indicated slow progress, abandonment rates were higher and users’ subjective experience more negative than if the early feedback indicated faster progress. In the second experiment, intermittent feedback seemed to minimize the costs of discouraging feedback while preserving the benefits of encouraging feedback. Overall, the results suggest that when progress seems to outpace users’ expectations, feedback can improve their experience though not necessarily their completion rates; when progress seems to lag behind what users expect, feedback degrades their experience and lowers completion rates.

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.

Scientific problem solving often involves concordance (or discordance) analysis among the result sets from different approaches. For example, different scientific analysis methods with the same samples often lead to different or even conflicting conclusions. To reach a more judicious conclusion, it is crucial to consider different perspectives by checking concordance among those result sets by different methods. In this paper, we present an interactive visualization tool called ConSet, where users can effectively examine relationships among multiple sets at once. ConSet provides an overview using an improved permutation matrix to enable users to easily identify relationships among sets with a large number of elements. Not only do we use a standard Venn diagram, we also introduce a new diagram called Fan diagram that allows users to compare two or three sets without any inconsistencies that may exist in Venn diagrams. A qualitative user study was conducted to evaluate how our tool works in comparison with a traditional set visualization tool based on a Venn diagram. We observed that ConSet enabled users to complete more tasks with fewer errors than the traditional interface did and most users preferred ConSet.

Specifying event sequence queries is challenging even for skilled computer professionals familiar with SQL. Most graphical user interfaces for database search use an exact match approach, which is often effective, but near misses may also be of interest. We describe a new similarity search interface, in which users specify a query by simply placing events on a blank timeline and retrieve a similarity-ranked list of results. Behind this user interface is a new similarity measure for event sequences which the users can customize by four decision criteria, enabling them to adjust the impact of missing, extra, or swapped events or the impact of time shifts. We describe a use case with Electronic Health Records based on our ongoing collaboration with hospital physicians. A controlled experiment with 18 participants compared exact match and similarity search interfaces. We report on the advantages and disadvantages of each interface and suggest a hybrid interface combining the best of both.

This paper will discuss three examples of use of scenarios in user-centred design. The examples are from projects that the author has been involved with. Common to them are the use of scenarios to support the tensions between reflection and action, between typical and critical situations, and between plus and minus situations. The paper will illustrate how a variety of more specific scenarios emphasising, for example, critical situations, or even caricatures of situations are very useful for helping groups of users and designers being creative in design. Emphasising creativity in design is a very different view on the design process than normally represented in usability work or software/requirements engineering, where generalising users' actions are much more important than the, in this paper, suggested richness of and contradiction between actual use situations. In general the paper proposes to attune scenarios to the particular purposes of the situations that they are to be used in, and to be very selective based on these purposes

Developing software components with user interfaces that can be adapted to diverse reuse situations is challenging. Examples of such adaptations include extending, composing and reconfiguring multiple-component user interfaces, and adapting component user interfaces to particular user preferences, roles and subtasks. We describe our recent work in facilitating such adaptation via the concept of “user interface aspects”, which facilitate effective component user interface design and realisation using an extended component-based software architecture

An exclusively visual approach to the development of database applications is introduced. Graphical tools and techniques are designed to represent all components of an application system, and all phases of the development process. Data, constraints, queries, transactions and programs are all expressed graphically. Analysis, design, maintenance, and even inference are done using graphical techniques. The visual approach is expected to be most appropriate for end users, and it is likely to encourage end user participation in application development

Scenarios of human-computer interaction help us to understand and to create computer systems and applications as artifacts of human activity-as things to learn from, as tools to use in one's work, as media for interacting with other people. Scenario-based design of information technology addresses five technical challenges. Scenarios evoke reflection in the content of design work, helping developers coordinate design action and reflection. Scenarios are at once concrete and flexible, helping developers manage the fluidly of design situation. Scenarios affords multiple view of an interaction, diverse kinds and amounts of detailing, helping developers manage the many consequences entailed by an given design move. Scenarios can also be abstracted and categorized, helping designers to recognize, capture, and reuse generalizations, and to address the challenge that technical knowledge often lags the needs of technical design. Finally, scenarios promote work-oriented communication among stakeholders, helping to make design activities more accessible to the great variety of expertise that can contribute to design, and addressing the challenge that external constraints designers and clients often distract attention from the needs and concerns of the people who will use the technology

Most work in HCI focuses on interaction in the small: where tasks take a few minutes or hours and individual actions receive feedback within seconds. In contrast, many collaborative activities occur over weeks or months and the turnaround of individual messages may take hours, days or even weeks. This slow pace of interaction brings its own problems, especially when expected responses do not occur. This paper analyses these problems, focusing on the triggers which initiate activities and the way processes recover when triggers are missed or misinterpreted. Furthermore, we are able to consider processes which cross organisational boundaries. We draw on theoretical analysis, an exploratory case study of conference organisation and recent application of the techniques to a student placement office. During the studies, a pattern of recurrent activities was discovered, the 4Rs (request, receipt, response and release), which we believe to be generic to this class of collaborative process.

Passwords are the almost universal authentication mechanism, even though they are basically flawed and cause problems for users due to poor memorability. Graphical methods of authentication have recently excited some interest but little is known about their actual efficacy. There are basically two types of graphical authentication mechanisms: recognition-based and location-based—also called visuo-spatial mechanisms. Whereas some kinds of recognition-based graphical authentication mechanisms have been evaluated by various researchers, there is still a need to investigate location-based graphical authentication mechanisms in a more rigorous fashion to determine whether they could be a viable alternative to traditional passwords for web usage. This paper discusses graphical authentication mechanisms in general and reports on the evaluation of one particular visuo-spatial mechanism, aimed at augmenting the password paradigm by providing a way to record passwords securely. Results and findings are presented, and conclusions drawn, some of which can also be applied to other types of visuo-spatial mechanisms. We also propose a set of metrics which can be used to measure the quality of web authentication mechanisms and apply these to a range of existing authentication mechanisms.

Learning characteristics, as informed by research, vary for each individual learner. Research suggests that knowledge is processed and represented in different ways and that students prefer to use different types of resources in distinct ways. However, building Adaptive Educational systems that adapt to different learning characteristics is not easy. Major research questions exist such as: how are the relevant learning characteristics identified, how does modelling of the learner take place and in what way should the learning environment change for users with different learning characteristics? EDUCE is one system that addresses these challenges by using Gardner’s theory of multiple intelligences (MI) as the basis for dynamically modelling learning characteristics and for designing instructional material. This paper describes a research study, using EDUCE, that explores the effect of using different adaptive presentation strategies and the impact on learning performance when material is matched and mismatched with learning preferences. The results suggest that students with low levels of learning activity, and who use only a limited number of the resources available, have the most to benefit from adaptive presentation strategies and that surprisingly learning gain increases when they are provided with resources not normally preferred.

This paper describes a novel instantiation of a digital photo library in a public access system. It demonstrates how designers can utilize characteristics of a target user community (social constraints, trust, and a lack of anonymity) to provide capabilities, such as unrestricted annotation and uploading of photos, which would be impractical in other types of public access systems. It also presents a compact set of design principles and guidelines for ensuring the immediate usability of public access information systems. These principles and guidelines were derived from our experience developing PhotoFinder Kiosk, a community photo library. Attendees of a major HCI conference (CHI 2001 Conference on Human Factors in Computing Systems) successfully used the tool to browse and annotate collections of photographs spanning 20 years of HCI-related conferences, producing a richly annotated photo history of the field of human–computer interaction. Observations and usage log data were used to evaluate the tool and develop the guidelines. They provide specific guidance for practitioners, as well as a useful framework for additional research in public access interfaces.

We present two empirical studies of visual search in dynamic 3D visualisations of large, randomly ordered, photo collections. The aim is to assess the possible effects of geometrical distortions on visual search effectiveness, efficiency and comfort, by comparing the influence of two perspective representations of photo collections on participants’ performance results and subjective judgments. Thumbnails of the 1000 or so photographs in each collection are plastered on the lateral surface of a vertical cylinder, either on the inside (inner view, IV) or on the outside (outer view, OV). IV and OV suggest two different interaction metaphors: locomotion in a virtual space (IV) versus manipulation of a virtual object (OV). They also implement different perspective distortions: enlargement and distortion of lateral columns (IV) versus enlargement of central columns and dwindling plus distortion of lateral columns (OV). Presentation of results focus on the second study, S2, which involved 20 participants and offered them strictly identical interaction facilities with the two views, unlike the initial pilot study, S1 (8 participants and slightly different interaction facilities between the two views). Participants in both studies were experienced computer users (average age: 25.15 years, SD: 3.13). They performed two types of basic visual tasks that are carried out repeatedly while navigating photo collections: (i) searching for a photo meeting specific, visual and thematic, criteria, the photo and its location in the collection being unknown to participants (ST1) and (ii) looking for a visually familiar photo, the location of the photo being familiar to participants (ST2). According to post-experiment questionnaires and debriefings, all participants in S2 save one judged both 3D views positively in reference to standard 2D visualisations. Half of them preferred IV over OV, four appreciated OV better, and six expressed no clear opinion. Preferences were mainly motivated by the effects of perspective distortions on thumbnail visibility. They were barely influenced by interaction metaphors (e.g., the feeling of immersion induced by IV). Despite large inter-individual differences in performance, a majority of participants carried out ST1 tasks more effectively and efficiently with IV than with OV, as regards error rates (statistically significant difference) and search times (tendency). Performance results for ST2 tasks were similar with the two views, due, probably, to the simplicity and brevity of ST2 tasks. Perspective distortions seem to have exerted less influence on participants’ visual strategies than horizontal scrolling, a dynamic feature common to both views. Qualitative analyses of participants’ behaviours suggest that IV has the potential to support spatial memory better than OV, presumably thanks to the locomotion metaphor. These results indicate that perspective views have the potential to facilitate and improve visual search in unstructured picture collections provided that distortions are adapted to users’ individual visual capabilities. Further research is needed to better understand: (i) the actual relations between visual exploration strategies and geometrical properties of perspective visualisations and (ii) the influence of the manipulation and locomotion metaphors on spatial memory. This knowledge is necessary to further improve the comfort and effectiveness of visual search in large unstructured picture collections, using 3D visualisations.

Investigation of augmented reality (AR) environments has become a popular research topic for engineers, computer and cognitive scientists. Although application oriented studies focused on audio AR environments have been published, little work has been done to vigorously study and evaluate the important research questions of the effectiveness of 3D sound in the AR context, and to what extent the addition of 3D sound would contribute to the AR experience. Thus, we have developed two AR environments and performed vigorous experiments with human subjects to study the effects of 3D sound in the AR context. The study concerns two scenarios. In the first scenario, one participant must use vision only and vision with 3D sound to judge the relative depth of augmented virtual objects. In the second scenario, two participants must co-operate to perform a joint task in a game-based AR environment. Hence, the goals of this study are (1) to access the impact of 3D sound on depth perception in a single-camera AR environment, (2) to study the impact of 3D sound on task performance and the feeling of ‘human presence and collaboration’, (3) to better understand the role of 3D sound in human-computer and human–human interactions, (4) to investigate if gender can affect the impact of 3D sound in AR environments. The outcomes of this research can have a useful impact on the development of audio AR systems which provide more immersive, realistic and entertaining experiences by introducing 3D sound. Our results suggest that 3D sound in AR environment significantly improves the accuracy of depth judgment and improves task performance. Our results also suggest that 3D sound contributes significantly to the feeling of ‘human presence and collaboration’ and helps the subjects to ‘identify spatial objects’.

Investigation of augmented reality (AR) environments has become a popular research topic for engineers, computer and cognitive scientists. Although application oriented studies focused on audio AR environments have been published, little work has been done to vigorously study and evaluate the important research questions of the effectiveness of three-dimensional (3D) sound in the AR context, and to what extent the addition of 3D sound would contribute to the AR experience. Thus, we have developed two AR environments and performed vigorous experiments with human subjects to study the effects of 3D sound in the AR context. The study concerns two scenarios. In the first scenario, one participant must use vision only and vision with 3D sound to judge the relative depth of augmented virtual objects. In the second scenario, two participants must cooperate to perform a joint task in a game-based AR environment. Hence, the goals of this study are (1) to access the impact of 3D sound on depth perception in a single-camera AR environment, (2) to study the impact of 3D sound on task performance and the feeling of ‘human presence and collaboration’, (3) to better understand the role of 3D sound in human–computer and human–human interactions, (4) to investigate if gender can affect the impact of 3D sound in AR environments. The outcomes of this research can have a useful impact on the development of audio AR systems, which provide more immersive, realistic and entertaining experiences by introducing 3D sound. Our results suggest that 3D sound in AR environment significantly improves the accuracy of depth judgment and improves task performance. Our results also suggest that 3D sound contributes significantly to the feeling of human presence and collaboration and helps the subjects to ‘identify spatial objects’.

Contemporary technology offers many benefits to older people, but these are often rendered inaccessible through poor software design. As the Internet increasingly becomes a source of information and services it is vital to ensure that older people can access these resources. As part of project funded by the UK government, a multi-disciplinary team set out to develop usable software that would help to introduce older people to the Internet. The first step was to develop an email system for older people with no experience of Internet use. The project was intended to show that it is possible to design usable technology for this group and to explore some of the issues involved in doing so. Design and technical challenges necessitated various tradeoffs. The system produced demonstrated the success of the design decisions: it was significantly easier to use than, and preferred to, a commercial equivalent by a group of older people with no experience of Internet use.

Human interactions with IT tools reproduce organizational cultural patterns in evolutionary terms which are similar to those seen in the evolution of human tools and language. This paper proposes that user adoption or rejection of new IT tools is derived from the cultural fitness of the tools in the organizational context rather than being close to the user's operational adaptation. The hypothesis proposed here requires an understanding of the correlation between language and tool use and an analysis of recent multi-disciplinary research in tool-mediated activity, language and cognition. Concepts of tool-mediated activity in a cultural context and their theoretical implications for HCI are examined by using the fields of anthropology, cognitive sciences and information technology. A comparative analysis of empirical data using cultural parameters is performed showing the effects of cultural fitness on the discretionary use of a new collaborative IT tool in an organizational context.

This article examines four existing or proposed standards for abstract description of user interfaces: UIML, XIML, XForms and URC. These are assessed with respect to a ‘universal remote console’ scenario, in which abstract user interface descriptions enable any user to access and control any compliant device or service in the local environment, using any personal device. Achieving usable interfaces in this scenario requires an abstract language that (a) separates data from presentation; (b) explicitly declares interface elements, their state, dependencies, and semantics; (c) incorporates alternative resources in a flexible way; and (d) supports remote control and different interaction styles. Of the technologies examined, XForms and URC provide the best match to the requirements. While XForms requires an appropriate context of use to provide full access, the URC standard will include specification of the context in which the language is to be used. Two specific research challenges are identified: semantic tagging and the development of effective authoring processes.

This is a call for informed debate on the ethical issues raised by the forthcoming widespread use of robots, particularly in domestic settings. Research shows that humans can sometimes become very abusive towards computers and robots particularly when they are seen as human-like and this raises important ethical issues. The designers of robotic systems need to take an ethical stance on at least three specific questions. Firstly is it acceptable to treat artefacts – particularly human-like artefacts – in ways that we would consider it morally unacceptable to treat humans? Second, if so, just how much sexual or violent ‘abuse’ of an artificial agent should we allow before we censure the behaviour of the abuser? Thirdly is it ethical for designers to attempt to ‘design out’ abusive behaviour by users? Conclusions on these and related issues should be used to modify professional codes as a matter of urgency.

This paper describes our ongoing attempts to build a communityware system by presenting a project of providing digital assistants to support participants in an academic conference. We provided participants at the conference with a personal assistant system with mobile and ubiquitous computing technologies and facilitated communication among the participants. We also made online services available via the Web to encourage the participants to continue their relationships even after the conference. In this paper, we show the system we provided for the project and report the results.

The Logical User Centred Interface Design (LUCID) method has been shown to provide a development approach which is both user-centred and which, with respect to selected usability criteria, leads to the identification of the optimum interface. Previously published evidence has focused on factors internal to the design of the interface itself. In this paper, the authors show how Taguchi techniques for total quality management, which are integrated within the method, can be extended to analyse external factors such as diversity within the user groups of shared interfaces. Application of the method to global, international and local interfaces is discussed.

Using the Technology Acceptance Model as a conceptual framework and a method of structural equation modeling, this study analyzes the consumer attitude toward Wi-Bro drawing data from 515 consumers. Individuals’ responses to questions about whether they use/accept Wi-Bro were collected and combined with various factors modified from the Technology Acceptance Model. The result of this study show that users’ perceptions are significantly associated with their motivation to use Wi-Bro. Specifically, perceived quality and perceived availability are found to have significant effect on users’ extrinsic and intrinsic motivation. These new factors are found to be Wi-Bro-specific factors, playing as enhancing factors to attitudes and intention.

The Technology Acceptance Model (TAM) [37] model, a derivative of the Theory of Reasoned Action (TRA) [26], attempts to explain the psychological determinants of attitudes, and subsequent acceptance behaviour, towards Information Technology (IT) in the workplace. The present study examined the efficacy of this psychologically based TAM within two samples of government workers experienced in the use of computers (N=108). All participants completed a self-report questionnaire consisting of both previously developed and purpose derived scales. The study achieved its purpose of replicating and validating a development of the TAM, although only moderate support for the model was found. The applied implications of the research and wider theoretical implications of the study are discussed.

Acceptance of adaptive museum guides raises important issues stemming from both the nature of the scenario (museum visit) and the very kind of technological approach adopted (adaptivity). As to the former, museum guides play a utilitarian role in a hedonic scenario; at present, however, it is not clear how this reflects on the balance between intrinsic and extrinsic motivations for guide acceptance. The adaptive nature of the guide, in turn, raises questions about the impact of the opaqueness of the system behavior, of the alleged loss of perceived control over the interaction, and the role of presentation personalization. All these issues are explored in this paper by means of a model derived from TAM and comprising both extrinsic and intrinsic motivational constructs. The results of a analysis of data from 115 subjects show that the motivational structure of the guide usage is mainly utilitarian, with intrinsic motivations playing a role insofar as they acquire an instrumental value. The impact of the control issues on acceptability is low and indirect, while the importance of the feedback provided by the system is confirmed. Finally, personalization positively impacts on user engagement, this way strengthening the empirical and theoretical groundings for work in adaptive systems.

The use of a touch-screen public access health information system was evaluated by monitoring system usage, by interviews with an opportunistic sample of 90 users and by other surveys. To get the largest number of users, such a system needs to be sited in a highly visible setting where there are lots of people passing. For most people, privacy does not appear to be a problem. However, some groups may require more privacy and when siting in ‘quieter’ places, such as a library this may be more important than in busier anonymous places, or in places where health is a ‘natural’ topic of interest. Waiting rooms may not be the best sites.

Given the increasingly important role the World Wide Web plays as an information source, and yet with the continuing problems that certain individuals, particularly those with disabilities and those using ‘non-standard’ Web browsing technology, it is vital that web resource providers be aware of design features which introduce barriers affecting the accessibility of on-line information. The role of the accessibility audit is seen as an important one in uncovering, describing, and explaining potential accessibility barriers present in a web site. It furthermore acts as an educational tool by raising awareness in accessible design amongst web designers and content providers in providing them with a recovery plan for improving the accessiblility of the audited resource, and potentially other resources. In 1999, the authors were commissioned to carry out accessibility audits of 11 web sites in the UK Higher Education sector. This paper discusses the development of the methodology used to carry out the audits, the findings of the audits in terms of accessibility levels of the subject sites, and feedback as a result of the auditing process. It concludes by looking at ways in which the methodology adopted may be tailored to suit specific types of web resource evaluation.

The increasing need to check Web site accessibility has stimulated interest in tools to aid the various activities involved. While some tools for this purpose already exist, we believe that there is a demand for making their support more flexible. In particular, there is often a need for validation of multiple sets of guidelines, repairing Web pages and providing better reports for the evaluators. In this paper, we discuss such issues and how we have addressed them in the design of MAGENTA, our new tool for supporting inspection-based evaluation of accessibility and usability guidelines.

Designing universally accessible user interfaces means designing for diversity in end-users and contexts of use, and implies making alternative design decisions, at various levels of the interaction design, inherently leading to diversity in the final design outcomes. Towards this end, a design method leading to the construction of a single interface design instance is inappropriate, as it cannot accommodate for diversity of the resulting dialogue artifacts. Therefore, there is a need for a systematic process in which alternative design decisions for different design parameters may be supported. The outcome of such a design process realizes a design space populated with appropriate designed dialogue patterns, along with their associated design parameters (e.g. user- and usage-context-attribute values). This paper discusses the Unified Interface Design Method, a process-oriented design method enabling the organization of diversity-based design decisions around a single hierarchical structure, and encompassing a variety of techniques such as task analysis, abstract design, design polymorphism and design rationale.

The notion of ‘universal access’ reflects the concept of an Information Society in which potentially anyone (i.e. any user) will interact with computing machines, at anytime and anyplace (i.e. in any context of use) and for virtually anything (i.e. for any task). Towards reaching a successful and cost effective realization of this vision, it is critical to ensure that the future interface development tools provide all the necessary instrumentation to support inclusive design, i.e. facilitate inclusive development. In the meantime, it is crucial that both tool developers and interface developers acquire awareness regarding the key development features they should pursue when investigating for the most appropriate software engineering support in addressing such a largely demanding development goal (i.e. universally accessible interactions). This paper discusses a corpus of key development requirements for building universally accessible interactions that has been consolidated from real practice, in the course of six medium-to-large scale research projects, all completed, within a 10 years timeframe.

This paper discusses the design and use of a number of simple measurement methods that are available to the developers of small World Wide Web (Web)systems. The focus is on how the resulting data can be used to assist with re-designing the initial system. The author argues that the analysis of viewer usage patterns, together with the need for ever more sophisticated collection should form an essential part of the development life cycle of a Web-based system. The conclusion outlines some desirable features of such tools, based on development and maintenance experience on a University site.

Scenarios, in most situations, are descriptions of required interactions between a desired system and its environment, which detail normative system behaviour. Our studies of current scenario use in requirements engineering have revealed that there is considerable interest in the use of scenarios for acquisition, elaboration and validation of system requirements. However, scenarios have seldom been used to study inappropriate or exceptional system behaviour. To account for non-normative or undesired system behaviour, it is vital to predict (‘what can go wrong’) and explore the existence or occurrence of ‘exceptions’ in a scenario when the system 1System, here, is not just a pure software system but is a socio-technical system which has social technical and organisation dimensions with the user as an integral part of the system ¹ might be prevented from delivering the required service. Identification of exceptions and inclusion of additional requirements to prevent their occurrence or mitigate their effects yield robust and fault-tolerant design solutions.In this article, we present a prototype software tool called CREWS–SAVRE for systematic scenario generation and use. We describe the innovative features of the tool and demonstrate them with an example of tool’s use. Further, we have identified three kinds of exceptions: generic, permutation and problem exceptions, and have derived complex taxonomies of problem exceptions. We have populated SAVRE with the taxonomies of generic, permutation and problem exceptions. The exceptions can be chosen by the requirements engineer to include them in the generated scenarios to explore the correctness and completeness of requirements. In addition, the taxonomies of problem exceptions can also serve as checklists and help a requirements engineer to predict non-normative system behaviour in a scenario.

This paper reports the results of a study on the design and evaluation of the game and techniques which allow puzzles to be played in the absence of visual feedback. We have demonstrated that a camera-mouse can be used successfully for blind navigation and target location acquisition within a game field. To gradually teach the players the sequential learning method was applied. Blind exploration of the gamespace was augmented with sticky labels and overview sound cues, verbal and non-verbal, which can significantly reduce the cognitive load and facilitate mental matching and integration. The full-sticky labels technique does not require fine motor skills and allows a user to gain control over the game with a minimum level of skills. With the vertical sticky labels technique training was focused on the development of accurate head movements only on a horizontal plane. With practice, the players can use the non-sticky labels technique. After 240 trials (3–4 h), the cumulative experience of the blindfolded players was increased 22.5–27 times compared to the initial 10 trials.

An introduction to the different. knowledge elicitation methods in common use is given in this article. First, the considerations that are most important in determining the choice of knowledge elicitation method in practical business contexts are discussed. This is followed by a list of methods, described in terms of these considerations. The paper concludes with a brief discussion of the practical application of the methods.

From a language/action perspective (LAP), information systems are conceived as tools for social action and communication. To date, LAP-based approaches have tended towards the abstract, focusing primarily on business modelling and different business interaction patterns. In this paper, nine dimensions of information systems from a LAP point of view are developed. The dimensions are founded on the notion that information systems used within a business context have the ability to act and to support human action—they possess actability. The dimensions bring concrete design suggestions to systems development and evaluation by emphasizing aspects such as anonymization of information origin, appropriate visual presentation based on required action support, and the design of systems in relation to communication patterns and business responsibilities. Examples from a case study are discussed to show the applicability of the actability dimensions. The relationship between the suggested actability dimensions and commonly referred principles for assessing usability is elaborated.

This paper discusses three examples of use of scenarios in user-centred design. Common to the examples are the use of scenarios to support the tensions between reflection and action, between typical and critical situations, and between plus and minus situations. The paper illustrates how a variety of more specific scenarios emphasising, e.g. critical situations, or even caricatures of situations are very useful for helping groups of users and designers being creative in design. Emphasising creativity in design is a very different view on the design process than normally represented in usability work or software/requirement engineering, where generalising users’ actions are much more important than, in this paper, the suggested richness of and contradiction between actual use situations. In general the paper proposes to attune scenarios to the particular purposes of the situations they are to be used in, and to be very selective based on these purposes.

In the past, Cscw systems have been studied with little consideration of the social context in which they will be used (see Ref. [1]). A framework of social context has been proposed [1] that takes the social aspects of a collaborating community to be a vital consideration in the design of Cscw systems. This paper aims to extend Mantovani's framework to deal with the issues of human error. The social context plays a large part in the cause, detection, level of consequence and recovery of erroneous actions in Cscw. This paper considers how current classification of human errors might be adapted for application in Cscw. A framework has been proposed which can be used in the analysis of the social context of Cscw.

This paper discusses the effects of introducing new distributed and active instruments on narrative activities in a school environment. We address the issue of how the Pogo instruments change children's activity when they invent stories. The results enable us to compare the way the activity is carried out, both in its conventional context and with the Pogo instruments, mainly along three main lines of investigation: the collective dimension, the use of space and the structure of the narrative. The results also show that using the instruments increase the collective or group dimension of the creative process, particularly the role diversification and participation of the children. These instruments support children's efforts to structure narratives and thereby produce richer stories. This research was carried out within the Pogo Project by a multidisciplinary team that included interactive design and user-centered approaches within the EC I3 programme on ‘Exploring New Learning Futures for Children’.

Communication between physically distributed people in industrial and safety-critical domains is often spoken and mediated through walkie-talkies, or closed-circuit intercoms. Because this kind of communication is hampered by noise, radio interference, lack of persistency, etc. vital information is sometimes lost. In response to this challenge, this paper discusses the use of ‘canned’ text-based messaging as a supplement for improving such communication. Based on data from ethnographic studies of work activities in an industrial domain, and grounded in a theoretical model of communication, we have designed and evaluated a mobile canned communication prototype system facilitating exchange of predefined text messages, a persistent graphical representation of the operation in progress, and a filtered list of completed tasks. Results from two evaluations show that in the domain considered, canned text-based communication has a potential to supplement voice and assist in overcoming some of the inherent problems of spoken communication. Yet using a textual and persistent mode of communication also raises new challenges such as choice of modality, speed, flexibility and handling situations deviating from standard procedures.

The organisation of actual design activities, even by experts involved in routine tasks, is not appropriately characterised by the retrieval of pre-existing plans, but is opportunistic (possibly with hierarchical episodes at a local level, but not globally hierarchical). Actually executed design actions depend, at each moment t, on the evaluation of actions proposed at t−1. These proposals can be made by preestablished plans, but also by other action-proposal knowledge structures. This position is supported by results from diverse empirical design studies. A major reason why design activities are organised opportunisically is that, even if designers possess plans which they may retrieve and use, the designers very often deviate from these plans so that their activities satisfy action-management constraints, of which the most important is cognitive economy. Two types of variables underlying this opportunism are discussed: situational and processing. If design is opportunistically organised, a support system which imposes a hierarchically structured design process will probably handicap designers. Suggestions for systems offering real support are formulated.

The ADA-method is an attempt to integrate work environment issues into a usability evaluation method. The intention is to provide a method that can be used for the analysis of computer systems that are used by skilled professionals as a major part of their work. An ADA-analysis is performed as a semi-structured observation interview. The objectives of the ADA-method are (1) to identify usability and cognitive work environment problems in a computer supported work situation, and (2) to be a basis for further analysis and discussions concerning improvements of the system. The method was designed to suit the needs of occupational health specialists as a complement to their traditional methods for investigating physical and psychosocial work environments. However, the method has a more general applicability as it can be taught to any usability expert to facilitate work environment considerations in their analysis and evaluation work. Furthermore, the paper reports on the use of the method in several different settings and the results thereof.

The wide variety of devices currently available, which is bound to increase in the coming years, poses a number of issues for the design cycle of interactive software applications. Model-based approaches can provide useful support in addressing this new challenge. In this paper we present and discuss a method for the design of nomadic applications showing how the use of models can support their design. The aim is to enable each interaction device to support the appropriate tasks users expect to perform and designers to develop the various device-specific application modules in a consistent manner.

Software components are becoming increasingly popular design and implementation technologies that can be plugged and played to provide user-enhanceable software. However, developing software components with user interfaces that can be adapted to diverse reuse situations is challenging. Examples of such adaptations include extending, composing and reconfiguring multiple component user interfaces, and adapting component user interfaces to particular user preferences, roles and subtasks. We describe our recent work in facilitating such adaptation via the concept of user interface aspects, which support effective component user interface design and realisation using an extended, component-based software architecture.

This paper describes USE-IT, a knowledge-based tool for automating the design of interactions at the physical level, so as to ensure accessibility of the target user interface by different user groups, including people with disabilities. To achieve this, USE-IT elicits, manipulates and interprets representations of design knowledge in order to reason about, select and decide upon lexical adaptation constituents of a user interface. Adaptation constituents are attributes of abstract interaction object classes. USE-IT generates a collection of adaptation rules (i.e. a lexical specification scenario), based on design constraints generated from three basic knowledge sources: (a) the user model, (b) the task schema, and (c) a set of platform constraints (i.e. interaction objects, attributes, device availability, etc.). A data structure called the adaptability model tree has been designed to (i) facilitate the development of plausible semantics of adaptation at the lexical level of interaction, (ii) allow unification of design constraints, and (iii) enable selection of maximally preferred design options. The output of USE-IT can be subsequently interpreted by the run-time libraries of a high-level user interface development toolkit, which provides the required implementation support for realizing the user-adapted interface on a target platform.

The information globalization induced by the rapid development of the Internet and the accompanying adoption of the Web throughout the society leads to Websites which reach large audiences. The diversity of the audiences and the need of customer retention require active Websites, which expose themselves in a customized or personalized way: We call those sites User-adapted Websites. New technologies are necessary to personalize and customize content. Information filtering can be used for the discovery of important content and is therefore a key-technology for the creation of user-adapted Websites. In this article, we focus on the application of collaborative filtering for user-adapted Websites. We studied techniques for combining and integrating content-based filtering with collaborative filtering in order to address typical problems in collaborative filtering systems and to improve the performance. Other issues which are mentioned but only lightly covered include user interface challenges. To validate our approaches we developed a prototype user-adapted Website, the Active Web-Museum, a museum Website, which exposes its collection in a personalized way by the use of collaborative filtering.

Context-aware devices are able to take advantage of fusing sensory and application specific information to provide proper information on a situation, for more flexible services, and adaptive user interfaces (UI). It is characteristic for handheld devices and their users that they are continuously moving in several simultaneous fuzzy contexts. The dynamic environment sets special requirements for usability and acceptance of context-aware applications. Context-aware applications must be able to operate sensibly even if the context recognition is not 100% reliable and there are multiple contexts present at the same time. We present an approach for controlling context-aware applications in the case of multiple fuzzy contexts. This work has several potential applications in the area of adaptive UI application control. Our study is focused on the adaptation of applications representing information in handheld devices. The design of controllers and experiments with real context data from user scenarios are presented. Experimental results show that the proposed approach enhances the capability of adapting information representation in a handheld device. User reactions indicate that they accept application adaptation in many situations while insisting on retaining the most control over their device. Moreover, user feedback indicates that abrupt adaptations and instability should be avoided in the application control.

This paper describes the development of Net Neighbours, an online shopping scheme that widens internet access to older people via volunteer telephone intermediaries. It outlines the processes of: problem identification, designing the telephone interaction, the financial model and the interface for the volunteer. It describes the application and adaptation of human computer interaction (HCI) techniques to address the needs of the local charity that co-developed the scheme. The paper begins by reporting the ethnographic work that led to the scheme; it then describes the pilot study conducted with Age Concern, York. It maps the various possible configurations for the scheme in a series of financial models expressed in tree diagrams and goes on to describe the use of pastiche scenarios in developing designs. Pastiche scenarios draw on fiction as a resource to explore, in an engaging manner, the social issues raised by technological innovations; the paper presents extracts from three such scenarios that were used to reason about dependability issues with Age Concern staff. The scheme is ongoing and plans are currently being made to extend it by recruiting university staff and other office workers as volunteer intermediaries. It is hoped that the scheme will become widely available across the city and in other locations around the UK. It is argued that volunteer telephone intermediaries can bridge digital divides and make Internet services accessible to those excluded either by age, disability or lack of resources. The development of the scheme is a case study in the ways that HCI techniques can be adopted and adapted in order to design for civil society.

Manuals and interactive help are tedious to provide, difficult to maintain, and difficult to ensure that they remain correct, even for simple systems. The result is a loss in product quality, felt particularly by users and designers committed to long-term product development. The paper shows that it is possible to systematically put a system specification and its documentation into exact correspondence. It follows that much previously manual work can be done automatically — and with considerable advantages, including guaranteed correctness and completeness, as well as supporting powerful new features such as intelligent adaptive assistance. This paper shows how interactive assistance can be provided to answer ‘how to?’, ‘why not?’ and other questions.

Can readability on small screens be improved by using adaptive Rapid Serial Visual Presentation (RSVP) that adapts the presentation speed to the characteristics of the text instead of keeping it fixed? In this paper we introduce Adaptive RSVP, describe the design of a prototype on a mobile device, and report findings from a usability evaluation where the ability to read long and short texts was assessed. In a latin-square balanced repeated-measurement experiment, employing 16 subjects, two variants of Adaptive RSVP were benchmarked against Fixed RSVP and traditional text presentation. For short texts, all RSVP formats increased reading speed by 33% with no significant differences in comprehension or task load. For long texts, no differences were found in reading speed or comprehension, but all RSVP formats increased task load significantly. Nevertheless, Adaptive RSVP decreased task load ratings for most factors compared to Fixed RSVP. Causes, implications, and effects of these findings are discussed.

The potential of the Internet and intranets to facilitate development of clinical information systems has been evident for some time. Most Web-based clinical workstation interfaces, however, provide merely a loose collection of access channels. There are numerous examples of systems for access to either patient data or clinical guidelines, but only isolated cases where clinical decision support is presented integrally with the process of patient care, in particular, in the form of active alerts and reminders based on patient data. Moreover, pressures in the health industry are increasing the need for doctors to practice in accordance with ‘best practice’ guidelines and often to operate under novel healthcare arrangements. We present the Care Plan On-Line (cpol) system, which provides intranet-based support for the SA HealthPlus Coordinated Care model for chronic disease management. We describe the interface design rationale of cpol, which is based on constrained adaptation of the user interface while maintaining user control. We also describe the cpol implementation framework, which is flexible and broadly applicable to support new healthcare models over intranets or the Internet.

The paper explores the application of predictive text generation to the human-computer interface. Predictive techniques exploit the statistical redundancy of language to accelerate and amplify user inputs. Acceleration is achieved by making more likely language elements faster to select, while amplification is accomplished by selection of concatenated elements. The language models used are created adaptively, decoupling the prediction mechanism from the application domain and user's vocabulary, and conforming automatically to whatever kind of text is entered. A device called the ‘reactive keyboard’ is described along with two user interface implementations, one for keyboard entry and the other for a mouse/window environment. A clear separation is made between the system's user interface and the underlying model it employs, and the two versions share the same prediction technique and adaptive modelling mechanism. The basic idea is to order context-conditioned candidate strings, which are predicted by the model, according to frequency and display them for selection.