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Designers of Intelligent Tutoring Systems (ITS) have long been interested in delivering personalised teaching to individual students, typically by ensuring that the student receives content appropriate to their skills and knowledge. Nonetheless, a more holistic view on what constitutes good teaching practice has challenged whether this approach to user modelling is sufficient. Teaching is not only defined by what is taught, but also by how it is taught. In this paper, we demonstrate that exploratory design research can support this view by generating a more inclusive set of user attributes for purposes of user modelling. Through a case study, we show that design research for user modelling can function as a boundary object serving three important roles, that underpin more specifically the design of user modelling and more broadly ITS design. First, design research can establish common ground by encapsulating domain knowledge in an accessible form. This can support diverse project stakeholders to make decisions on what is to be modelled. Second, design research can reveal a wide range of teaching and learning perspectives that in turn introduce transparency to the decision-making process of user modelling and provoke a sense of criticality and accountability amongst project stakeholders. Third, design research can build new bridges between the design of the technology and the user model that underpins it. To this end, user attributes deemed important, yet too complex or cumbersome to develop, can become design principles in the context of the overall ITS design.

Scanning keyboards are used as augmentative communication aids by persons with severe speech and motion impairments. Literature reports two approaches for the design of scanning keyboards; design based on the experience and intuition of designers and user model based design methods. None of these approaches, however, considers user errors in the design process, potentially limiting the practical usefulness of the designs. We have performed experiments in order to study user errors on scanning keyboards. We have found that two types of errors affect performance of scanning keyboard users significantly, namely (a) timing error that occurs when a user fails to select a key at the appropriate time and (b) selection error that occurs when the user selects a wrong key. These errors have been found to increase users' text entry time by as high as 65% and 35%, respectively. Based on empirical observations, we have developed a state transition model of user behavior during user-keyboard interaction. The model comprises of four states, each of which represents the physical and cognitive state of the user at particular instant of the interaction. The transitions are caused by users' physical, cognitive and perceptual activities. We have found that the errors could be explained as caused due to the problems in making the transitions properly. In addition to explaining errors, the model has helped us to predict distribution of error probabilities with respect to the distance between keys. We have used the model predicted error distributions to develop principles for scanning keyboard design that aim to reduce user errors. The principles state that the frequently used key pairs should be placed apart by a minimum distance, which has been obtained from the error distributions, in order to reduce errors. The method and results of the study, the user model and the design principles are presented in this paper.

Human-like characters in the interface may evoke social responses in users, and literature suggests that realism is the most important factor herein. However, the effects of interface characters on the user are not well understood. We developed an integrative framework, called I-PEFiC, to explain 'persona' and realism effects on the user. We tested an important part of the model using an experimental design in which 140 middle school students were class-wise shown an informative virtual reality demonstration that incorporated either a realistic or an unrealistic (fantasy) interface character, or no character. Findings show, first, no persona effect on task performance. We discuss how user engagement might be related to persona effects. Second, designed realism of the interface character contributed to user engagement when controlled for various user perceptions. Moreover, perceived aesthetics and task-relevance further influenced user engagement. Third, user engagement and task performance combined better predicted satisfaction than either one of the factors alone. In sum, several appearance- and task-related factors contributed to user engagement and user satisfaction. Thus, realism is not all. © 2006 Elsevier B.V. All rights reserved.

This study aims to establish a model-based approach for user interface design that simultaneously considers the system's information hierarchy, users' task procedure knowledge, and system interfaces. The approach is based on a framework that contains multiple interaction models to express both system elements and users' knowledge. The framework evaluates system interface through the interaction between user's knowledge on interface, task procedure and information structure perceived by the user in the system. The interface is evaluated by its contribution to the users' task performance and system navigation. These three factors were defined as design factors that affect users' task performance. Through the crosscheck process of models, the relation between information, interface, and task procedure is calculated into combined difficulty index (CDI) that expresses the difficulty of a system interface that users would experience during the use of system. A user test was conducted for the validation of the CDI. The difficulties of the interface of a mobile healthcare system were predicted with the CDI, and the predictions were compared with the experimental results, where the users' performance showed consistence with the prediction.

This paper discusses the use of theatrical techniques to communicate to designers the user requirements for IT interfaces - particularly those of ''extreme users'' such as older people. The methodology and processes of producing such material in a video form are described, together with the strengths and weaknesses of this approach. The paper concludes by suggesting the various roles live theatre can play in user centered design. Although the research, on which this paper is based, focuses on the challenges presented by older and disabled users, the techniques described are applicable to a wider range of users.

Several comprehensive User Centred Design methodologies have been published in the last decade, but while they all focus on users, they disagree on exactly what activities should take place during the User Needs Analysis, what the end products of a User Needs Analysis should cover, how User Needs Analysis findings should be presented, and how these should be documented and communicated. This paper highlights issues in different stages of the User Needs Analysis that appear to cause considerable confusion among researchers and practitioners. It is our hope that the User-Centred Design community may begin to address these issues systematically. A case study is presented reporting a User Needs Analysis methodology and process as well as the user interface design of an application supporting communication among first responders in a major disaster. It illustrates some of the differences between the User-Centred Design and the Requirements Engineering communities and shows how and where User-Centred Design and Requirements Engineering methodologies should be integrated, or at least aligned, to avoid some of the problems practitioners face during the User Needs Analysis.

This paper describes a framework that serves as a reference for classifying user interfaces supporting multiple targets, or multiple contexts of use in the field of context-aware computing. In this framework, a context of use is decomposed in three facets: the end users of the interactive system, the hardware and software computing platform with which the user have to carry out their interactive tasks and the physical environment where they are working. Therefore, a context-sensitive user interface is a user interface that exhibits some capability to be aware of the context (context awareness) and to react to changes of this context. This paper attempts to provide a unified understanding of context-sensitive user interfaces rather than a prescription of various ways or methods of tackling different steps of development. Rather, the framework structures the development life cycle into four levels of abstraction: task and concepts, abstract user interface, concrete user interface and final user interface. These levels are structured with a relationship of reification going from an abstract level to a concrete one and a relationship of abstraction going from a concrete level to an abstract one. Most methods and tools can be more clearly understood and compared relative to each other against the levels of this framework. In addition, the framework expresses when, where and how a change of context is considered and supported in the context-sensitive user interface thanks to a relationship of translation. In the field of multi-target user interfaces is also introduced, defined, and exemplified the notion of plastic user interfaces. These user interfaces support some adaptation to changes of the context of use while preserving a predefined set of usability properties

This editorial paper introduces an emerging area for human–computer interaction research, which concerns interaction design and children. To avoid treating children as a homogeneous user group, it discusses some perspectives on their development, their use of technology for entertainment and education and, finally, how to involve children in the various stages of the design process.

This paper addresses the problems involved in the progress through evaluation and redesign from one interface prototype to the next stage of development. An approach is proposed based on situated action techniques for the early identification of user interface issues and their translation into design factors that lead to design improvements. The approach can be used within parallel prototyping or iterative development. Situated action is increasingly popular for the participative identification of user requirements for information systems and is usually implemented at an early stage in systems development. In contrast the most frequently used method for user participation within detailed interface design is within iterative user-based evaluation which is often performed relatively late in the development. The method described involves linking developer–user contextual evaluation sessions, where developers observe user's responses to an interactive prototype, and team evidence analysis sessions, where a group of designers work together to derive design decisions with the evidence collected from the users. The proposed method is tested in an experimental design. The proposed techniques provide a rich source of user evidence that can be brought to bear on the enhancement of prototype user interfaces. The study also showed how team working within a group of developers is important to effective design.

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.

Prototypes of interactive computer systems have been built that can begin to detect and label aspects of human emotional expression, and that respond to users experiencing frustration and other negative emotions with emotionally supportive interactions, demonstrating components of human skills such as active listening, empathy, and sympathy. These working systems support the prediction that a computer can begin to undo some of the negative feelings it causes by helping a user manage his or her emotional state. This paper clarifies the philosophy of this new approach to human–computer interaction: deliberately recognising and responding to an individual user's emotions in ways, that help users meet their needs. We define user needs in a broader perspective than has been hitherto discussed in the HCI community, to include emotional and social needs, and examine technology's emerging capability to address and support such needs. We raise and discuss potential concerns and objections regarding this technology, and describe several opportunities for future work.

A novel approach for improving the effectiveness and efficiency of human–computer interactions through an intelligent graphical user interface (GUI) is presented in this paper. It is demonstrated that through monitoring the user's actions, the system can determine the intents of the user, transforming the deduced intentions into system actions. Understanding of the user's implicit actions can reduce the burden on the user in terms of required explicit commands. Hence, a human friendlier computer system is built. One method to assess the effectiveness of the user interface enhancements is by reduction in the number of operations performed by the user in achieving a specific goal while using the GUI. The enhanced graphical user interface described in this paper is a conventional GUI enhanced with an intelligent control module. The intelligent component is composed of a group of software agents that cooperate and compete to control the system. A computer mouse is used as the input device, through which the user performs a number of clicks and drag-and-drop tasks, while selecting and moving objects on the computer screen. The intelligent module monitors the movements and states of the mouse and the cursor, and aids the user based on the multiple agents’ determinations of the user's sub-goals. Experimental results are presented, where human subjects achieved specific goals using the GUI, with and without the intelligent control module. Initial experiments have confirmed that the novel technique is a feasible approach for designing an effective and efficient intelligent GUI, as it reduces the amount of work required from the human user who is interacting with the computer.

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.

Tools which provide graphical editing techniques for the design of user interface presentations are increasingly commonplace. Such tools vary widely in the mechanisms used to define user interfaces and while some are general purpose, others are targeted at particular application domains. Designers faced with varying requirements must choose one tool and live with its shortcomings, purchase a number of different tools, or implement their own. The paper describes an approach to facilitating the latter by providing a library of augmented user interface components called MOG objects which embody both end-user and editing semantics. User interface design tools based on this approach need only provide mechanisms for composing MOG objects into user interfaces and the addition of any other, higher-level functionality. MOG-based user interfaces retain an in-built editing capability and are inherently tailorable.

This paper discusses user modelling techniques and presents the design and implementation of the 3M user modelling interface of INTEREX. INTEREX is an expert system for X-ray topographic image interpretation which assists its users in identifying and analysing a number of defects that can occur in high-quality crystals. 3M consists of a monitor, a model and a modifier. It is used to adapt the consultation route and the explanations provided by INTEREX to three categories of users. It demonstrates the use-of an implicit, individual, dynamic and long-term user model to enable an expert system to accommodate users with different levels of expertise.

User models can be embedded into a wide range of computer applications to enhance the quality of the user interface. The development of embedded user models (EUMs) draws on research in cognitive science and systems engineering and should be of interest to designers of user interfaces and researchers in human-computer interaction. This paper consolidates ideas about EUMs formed in the course of four projects funded under the British Government's Alvey Programme on advanced information technology. It discusses the relationship between user models, knowledge representation, human inference and instructional strategies, and presents views about the current state of the art in precompetitive research systems, its limitations and possible future directions for work.