In almost all computer applications, users must enter correct words for the desired objects or actions. For success without extensive training, or in first-tries for new targets, the system must recognize terms that will be chosen spontaneously. We studied spontaneous word choice for objects in five application-related domains, and found the variability to be surprisingly large. In every case two people favored the same term with probability <0.20. Simulations show how this fundamental property of language limits the success of various design methodologies for vocabulary-driven interaction. For example, the popular approach in which access is via one designer's favorite single word will result in 80-90 percent failure rates in many common situations. An optimal strategy, unlimited aliasing, is derived and shown to be capable of several-fold improvements.

One of the most sweeping changes ever in the ecology of human cognition may be taking place today. People are beginning to learn and use very powerful and sophisticated information processing technology as a matter of daily life. From the perspective of human history, this could be a transitional point dividing a period when machines merely helped us do things from a period when machines will seriously help us think about things. But if this is so, we are indeed still very much within the transition. For most people, computers have more possibility than they have real practical utility.

This paper describes a new approach for dealing with the vocabulary problem in human-computer interaction. Most approaches to retrieving textual materials depend on a lexical match between words in users' requests and those in or assigned to database objects. Because of the tremendous diversity in the words people use to describe the same object, lexical matching methods are necessarily incomplete and imprecise [5]. The latent semantic indexing approach tries to overcome these problems by automatically organizing text objects into a semantic structure more appropriate for matching user requests. This is done by taking advantage of implicit higher-order structure in the association of terms with text objects. The particular technique used is singular-value decomposition, in which a large term by text-object matrix is decomposed into a set of about 50 to 150 orthogonal factors from which the original matrix can be approximated by linear combination. Terms and objects are represented by 50 to 150 dimensional vectors and matched against user queries in this “semantic” space. Initial tests find this completely automatic method widely applicable and a promising way to improve users' access to many kinds of textual materials, or to objects and services for which textual descriptions are available.

Many surface computing prototypes have employed gestures created by system designers. Although such gestures are appropriate for early investigations, they are not necessarily reflective of user behavior. We present an approach to designing tabletop gestures that relies on eliciting gestures from non-technical users by first portraying the effect of a gesture, and then asking users to perform its cause. In all, 1080 gestures from 20 participants were logged, analyzed, and paired with think-aloud data for 27 commands performed with 1 and 2 hands. Our findings indicate that users rarely care about the number of fingers they employ, that one hand is preferred to two, that desktop idioms strongly influence users ’ mental models, and that some commands elicit little gestural agreement, suggesting the need for on-screen widgets. We also present a complete user-defined gesture set, quantitative agreement scores, implications for surface technology, and a taxonomy of surface gestures. Our results will help designers create better gesture sets informed by user behavior.

E-commerce and m-commerce demand for full-fledged, increasingly complex applications which need to offer ubiquitous access in terms of the anytime/anywhere/anymedia paradigma. From a software engineering point of view, the development of such ubiquitous web applications requires proper modeling methods in order to ensure architectural soundness and maintainability. Recently, web modeling methods started recognizing this fact by providing first concepts for dealing with ubiquity. In this paper, two of these modeling methods are compared, identifying their strengths and shortcomings. As a prerequisite, an evaluation framework is introduced, using the notion of customization as the uniform mechanism to enable ubiquity. Customization adapts a web application towards a particular context which reflects the environment the application is running in. To enable a holistic view on the development process of a ubiquitous web application, customization is regarded as a new modeling dimension, influencing all other tasks of ubiquitous web application development.

Users of natural language interfaces should conveniently be able to express the commands and queries that the background system can deal with, and the system should react quickly and accurately to all input. Among other things this means that the interface must be able to cope with connected dialogue. Furthermore, the design of natural language interfaces must take into consideration the characteristics of human-computer interaction instead of trying to mimic human interaction. This paper presents a dialogue manager for such natural language interfaces. To control the interaction it uses a dialogue grammar with information on the functional role of an utterance as conveyed in the linguistic structure. Focus structure is handled using dialogue objects recorded in a dialogue tree which can be accessed by the various modules for interpretation, generation and background system access. The Dialogue Manager is designed to facilitate customization to the sublanguage utilized in various applications. The paper also discusses the possibilities of generalizing the Dialogue Manager to other modalities.

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The web is more and more used as a platform for full-fledged, increasingly complex applications, where a huge amount of change-intensive data is managed by underlying database systems. From a software engineering point of view, the development of web applications requires proper modeling methods in order to ensure architectural soundness and maintainability. Existing modeling methods for web applications, however, fall short on considering a major requirement posed on today's web applications, namely customization. Web applications should be customizable with respect to various context factors comprising different user preferences, device capabilities and locations in mobile scenarios, to mention just a few. The goal of this paper is twofold. First, a framework of requirements, covering the design space of customizable web applications is suggested. Second, on the basis of this framework, existing approaches for developing customizable web applications are surveyed and general shortcomings are identified pointing the way to next-generation modeling methods.

An extension of the GUMS user modelling module is described which includes multiple inheritance between user stereotypes, multiple top level nodes in a network to allow a range of dimensions on which the user can be classified, and rules to change the stereotypes of users. A method is described using Wizard of Oz studies and interviews to provide the information to populate this model for applications and to provide rules to recognise which stereotypes apply to users. The use of the method and the user modelling module are illustrated for a human computer interface which supports multi-modal dialogue. The resulting co-operative dialogue with this interface is compared with the facilities offered by more complex alternative modelling approaches. Keyword Codes: H.1.2; I.2.4; H.5.2 Keywords: User/Machine Systems; Knowledge Representation Formalisms and Methods; User Interfaces 1. INTRODUCTION It is generally accepted that complex user interfaces should be tailorable to individual users. ...