For people with motion impairments, access to and independent control of a computer can be essential. Symptoms such as tremor and spasm, however, can make the typical keyboard and mouse arrangement for computer interaction difficult or even impossible to use. This paper describes three approaches to improving computer input effectivness for people with motion impairments. The three approaches are: (1) to increase the number of interaction channels, (2) to enhance commonly existing interaction channels, and (3) to make more effective use of all the available information in an existing input channel. Experiments in multimodal input, haptic feedback, user modelling, and cursor control are discussed in the context of the three approaches. A haptically enhanced keyboard emulator with perceptive capability is proposed, combining approaches in a way that improves computer access for motion impaired users.@en

It is known that many products are not accessible to large sections of the population. Designers instinctively design for able-bodied users and are either unaware of the needs of users with different capabilities, or do not know how to accommodate their needs into the design cycle. This aim of this paper is to present a methodological design approach for implementing inclusive design. A summary of the principal methods for designing for users with different capabilities is given along with a description of a model, the Inclusive Design Cube, that displays how the different approaches are complementary and can provide complete population coverage. A case study of the design of an information point for use in a post office, shall be used to highlight the use of the model.@en

People with motion-impairments often find it difficult to perform many of the actions required to interact with a computer. This paper presents the results of an on-going series of experiments designed to understand how using force feedback affects interaction for motion-impaired users. Point and click tasks were analyzed using new cursor control measures. The results showed significant improvement in throughput for all users with forcefeedback and the cursor control measures were effective in capturing the differences between the conditions.@en

It is known that many products, both software and hardware, are not accessible to large sections of the population. Designers instinctively design for able-bodied users and are either unaware of the needs of users with different capabilities, or do not know how to accommodate their needs into the design cycle. The aim of this paper is to present a methodological design approach for implementing inclusive interface design. This will begin with a discussion about what constitutes good inclusive design and suitable measures of success. A summary of the principal methods for designing for users with different capabilities is given along with a description of a model, the inclusive design cube, that displays how the different approaches are complementary and can provide complete population coverage. Two case studies shall be used to illustrate the use of the model. The first details the design of an interface for an interactive robot. The second looks at the design of an information point for use in a post office, and shall be used to highlight the use of both the design approach and the model.@en

This paper considers the differences between users with motion-impairments and able-bodied users when they interact with computers and the implications for user models. Most interface design and usability assessment practices are based on explicit or implicit models of user behaviour. This paper studies the applicability of an existing interface design user model to motion-impaired users for the relatively straightforward task of button activation. A discussion of the empirical results is provided and the paper concludes that there are significant differences between the behaviour of motion-impaired users and the accepted modelling theory.@en

"Point and click" interactions remain one of the key features of graphical user interfaces (GUIs). People with motion-impairments, however, can often have difficulty with accurate control of standard pointing devices. This paper discusses work that aims to reveal the nature of these difficulties through analyses that consider the cursor's path of movement. A range of potential cursor measures was applied, and a number of them were found to be significant in capturing the differences between able-bodied users and motion-impaired users, as well as the differences between a haptic force feedback condition and a control condition. The cursor measures found in the literature, however, do not make up a comprehensive list, but provide a starting point for analysing cursor movements more completely. Six new cursor characteristics for motion-impaired users are introduced to capture aspects of cursor movement different from those already proposed.@en

Current interface design practices are based on user models and descriptions derived almost exclusively from studies of able-bodied users (Keates et al., 1999). However, such users are only one point on a wide and varied scale of physical capabilities. Users with a number of different physical impairment conditions have the same desire to use computers as able-bodied people (Busby, 1997), but cannot cope with most current computer access systems (Edwards, 1995). It is important to identify the differences in interaction for users of differing physical capability, because the border between the labels 'able-bodied' and 'motion-impaired' users is becoming increasingly blurred as the generation of computer users inexorably becomes older and physically less capable. If user models are to retain their relevance, then they have to be able to reflect users' physical capabilities (Stary, 1997). Through empirical studies, this paper will show that there are very important differences between those with motion-impairments, whether elderly or disabled, and able-bodied users when they interact with computers. It attempts to quantify where those differences occur in the interaction cycle with the use of a very straightforward user model, the Model Human Processor (MHP) (Card, Moran and Newell, 1983), which describes interaction purely in terms of perception, cognition and motor component times. Although this model is simplistic compared to the more recent sophisticated models, it affords a simple and valuable insight into interaction cycles and offers a building block on which to base more comprehensive models. This work is predicated on the idea that the use of this model in detailed analysis of the basic interaction cycle will provide a means for studying motion impairment at both an individual and general level.@en