Understanding human movement is key to improving input devices and interaction techniques. This paper presents a study of mouse movements of motion-impaired users, with an aim to gaining a better understanding of impaired movement. The cursor trajectories of six motion-impaired users and three able-bodied users are studied according to their submovement structure. Performance measures based on submovement structure are described, including the frequency and duration of pauses between submovements, verification times, the number of submovements, the peak speed of submovements and the accuracy of submovements in two dimensions. The measures are shown to be sensitive to differences between users with dissimilar physical capabilities. Results include findings that some motion-impaired users pause more often and for longer than able-bodied users, require up to five times more submovements to complete the same task, and exhibit a greater decline in accuracy with increasing speed than able-bodied users.

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This paper presents a study investigating how the performance of motion-impaired computer users in "point and click" tasks varies with target distance (A), target width (W), and force-feedback gravity well width (GWW). Six motion-impaired users performed "point and click" tasks across a range of values for A, W, and GWW. Times were observed to increase with A, and to decrease with W. Times also improved with GWW, and, with the addition of a gravity well, a greater improvement was observed for smaller targets than for bigger ones. It was found that Fitts' Law gave a good description of behaviour for each value of GWW, and that gravity wells reduced the effect of task difficulty on performance. A model based on Fitts' Law is proposed, which incorporates the effect of GWW on movement time. The model accounts for 88.8% of the variance in the observed data.@en

Inclusive or universal design is about designing more accessible products and services for the widest possible range of users, regardless of age and capabilities. It requires better understanding and empathy with all potential users. Traditional user research methods are limited in accommodating a wide range of users and hence there is a need to find more appropriate methods of user research for inclusive design. This paper describes a method called 'Critical User Forums' which involves direct interaction between design teams and a mixed group of users with severe disabilities. The evaluation of the effectiveness of this method for inclusive design is based on the interviews of eight UK design consultancies that took part in a design competition, emphasising inclusive design and involving users, known as the 'DBA Design Challenge'. The contribution of critical users to the DBA projects is discussed and the design teams' viewpoints on such user involvement in the process are investigated. The paper concludes that Critical User Forums provide an ideal chance for designers to understand a wider range of users through direct interaction with them, thus helping designers build empathy with all potential users.@en

Despite increasing discussion in academia, genuinely 'inclusive' design in industry remains the exception rather than the rule. Based on literature reviews and industry surveys, this paper explores the barriers faced by manufacturers, retailers and design consultancies in adopting inclusive design. Drivers for practising inclusive design are also investigated. Using information about such barriers and drivers and linking them to business objectives, a basic framework for the business case for inclusive design is proposed. The paper contributes to the in-depth understanding of industry barriers and motivations for inclusive design and forms the basis for further research into the business case in an inclusive design context. The paper provides an insight into industry practice that is applicable to the design of User Interfaces for All.

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In the past twenty years, a number of resources and tools to support inclusive design have been developed. However, the impact of these resources and tools on industry is not evident -few industrialists have been using them in practice. Investigations into industry have identified unmet needs, for example, the lack of appropriate user data relating to inclusive design. The fundamental problem is that few resources and tools have been developed based on rigorous requirements capture. In fact, many of them were developed only because the developers think the information could be useful. It is essential to prepare a detailed requirements list when clarifying the task at the product planning stage. This is also true for developing resources and tools for inclusive design. Requirements capture plays an important role in identifying real needs from users and developing appropriate methods of support for them. This paper starts with a survey of available resources and tools for inclusive design, and a discussion on their merits and deficiencies in respect to industry application. A number of methods are employed for the requirements capture for an inclusive design toolkit, which leads to a consistent result. An outline of the toolkit is also presented.@en

Understanding human movement is key to improving input devices and interaction techniques. This paper presents a study of mouse movements of motion-impaired users, with an aim to gaining a better understanding of impaired movement. The cursor trajectories of six motion-impaired users and three able-bodied users are studied according to their submovement structure. Several aspects of the movement are studied, including the frequency and duration of pauses between submovements, verification times, the number of submovements, the peak speed of submovements and the accuracy of submovements in two-dimensions. Results include findings that some motion-impaired users pause more often and for longer than able-bodied users, require up to five times more submovements to complete the same task, and exhibit a correlation between error and peak submovement speed that does not exist for able-bodied users.@en

Despite increasing discussions on the topic in academia, truly inclusive design in industry remains the exception. This paper compares industry perceptions to inclusive design based on data collected from the UK, the US and Japan. Two comparisons are made. Firstly, the perceptions of UK consumer product manufacturers and retailers are compared with the perceptions of companies in the US and Japan. It appears that the attitudes to legislation and government regulations in the UK differ from those in the US and Japan. Secondly, comparisons are made between the perceptions of UK consumer industries. It was found that manufacturers, retailers and design consultancies all consider that major barrier obstructing their adoption of inclusive design were from the other parties, rather than themselves. The paper concludes that 'perception barriers' form the majority of the barriers to inclusive design and are the most significant, followed by 'technical barriers' and then 'organizational barriers.' A toolkit that has been developed to address the barriers identified is also presented.@en

The theory of inclusive design tends to require user involvement and iterative assessment throughout the whole design process. However, in an industrial context, companies are restricted by design constraints such as time and cost. Through investigating eight projects focusing on inclusive design, the authors highlight discrepancies between theoretical models and industry practice and analyse the underlying reasons. Related issues such as bottom-up design approaches and estimates of design exclusion are also discussed. It is concluded that a change of attitudes towards people with disabilities by people commissioning, as well as performing, design and the provision of design support tools are necessary to bring inclusive design theory and practice closer together.

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Haptic computer interfaces provide users with feedback through the sense of touch, thereby allowing users to feel a graphical user interface. Force feedback gravity wells, i.e. attractive basins that can pull the cursor toward a target, are one type of haptic effect that have been shown to provide improvements in "point and click" tasks. For motion-impaired users, gravity wells could improve times by as much as 50%. It has been reported that the presentation of information to multiple sensory modalities, e.g. haptics and vision, can provide performance benefits. However, previous studies investigating the use of force feedback gravity wells have generally not provided visual representations of the haptic effect. Where force fields extend beyond clickable targets, the addition of visual cues may affect performance. This paper investigates how the performance of motion-impaired computer users is affected by having visual representations of force feedback gravity wells presented on-screen. Results indicate that the visual representation does not affect times and errors in a "point and click" task involving multiple targets.

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'Design exclusion' arises when a product cannot be used effectively because of choices made during the design process. Understanding the causes of such design exclusion is essential if better products, which accommodate the widest range of user capabilities, are to be designed. This paper investigates the prevalence of multiple minor impairments among older users who are most vulnerable to design exclusion. Effective ways of representing these impairments are also discussed, with the aim of helping designers better understand user capabilities, and thus reduce design exclusion.@en

Many handheld electronic devices such as cellular phones, personal digital assistants (PDAs) and TV/video remote controls have become a part our daily life; and in recent years there has been competition amongst manufacturers to introduce increasingly compact forms of these products. Consequently, their sizes are decreasing gradually to palm size or smaller and the user-interface is becoming more difficult to interact with. Many of these products are not accessible to large sections of the population because the diversity in user capabilities and requirements was not accounted for during the design process. One reason for this is the lack of proper design guidelines to take account of the needs and expectations of a wider range of users. This paper focuses on the necessity of adopting inclusive design approaches in the design of handheld devices, describes some important design issues pertinent to these devices in general and finally aims to give a broad range of solutions that the designers can apply in a wide variety of circumstances when designing handheld electronic devices.@en

The world population is aging and the number of people who are experiencing a loss of functional capability is also on the increase. There is a need to design 'inclusive' products to accommodate this wider range of capabilities and to develop metrics to assess the success of such products. The case for inclusive design is presented as a balance between the demands a product makes of its users and the users' capabilities, along with a number of design metrics and data to enable their evaluation.@en

An inclusively-designed product should accommodate the widest possible range of user capabilities. Consequently, it is important for designers to know about the full range of potential user capabilities found across the general population when assessing product attributes prior to redesign or new concept development. A mapping between user capabilities and product assessment is thus required. This paper aims to find such a mapping through the application of a severity of impairment scale to product assessment.@en

In order to assess capability for product design, we aimed to develop new scales to assess the cognitive capability ranges for individuals by using items from the existing UK ONS scale to construct new scales, re-analysed in terms of cognitive requirements. The new scales were constructed by classifying each test item with reference to a simple cognitive user model representing an overview of cognition constructed from well-established findings in mainstream cognitive science [1]. Using the original data from 7,500 interviews of the original survey, new scorings were re-calculated from the resulting scales. These new scales: (1) Executive Function, (2) Memory, and (3) Expression and Comprehension, were compared with data from the existing scales in terms of the amounts of impairment indicated for a number of capability ranges. As a result, suggestions for the improvement of the ONS scales as measures of cognitive capability in product design were identified.@en

Everyday design solutions often cause unnecessary levels of discomfort or even exclusion, affecting mainly older adult users and people of all ages with a variety of functional impairments. Designers' intuitive and informal approaches to the evaluation of product usability and accessibility attributes are insufficient when addressing the needs of a wider population. This paper discusses the advantages of using more formal assessment approaches throughout the entire design process. A case study on domestic appliances illustrates the comparison between the implementation of three different assessment methods.@en

The world population is aging and the number of people who are experiencing a loss of functional capability is also on the increase. There is a need to design 'inclusive' products to accommodate this wider range of capabilities and to develop metrics to assess the success of such products. Successful inclusive design requires a balance between the demands a product makes of its users and the users' capabilities, along with a number of design metrics and data to enable their evaluation. If the balance is not correct, then there is the potential for design exclusion.@en

Inclusive design in the U.K. and its U.S. counterpart, universal design, present opportunities and challenges to industry. In order to encourage manufacturers and design companies to adopt more inclusive design practices, the research has been carried out to gain an understanding of why and how companies adopt inclusive design practices, what are the barriers when implementing them and what are the key strategies for facilitating inclusive/universal design in an industrial context. Based on interviews with a number of U.K. design consultancies and an investigation among manufacturers in the U.S., a comparison between U.K. consultant designers and U.S. consumer product manufacturers' perspectives on inclusive/universal design was made. It was found that designers are reluctant to sacrifice the aesthetics of the brand to design for inclusion, but nevertheless would like to have practical tools to help them develop more inclusive solutions. For manufacturers, the key motivation for such practices is that of government regulation and legislation requiring the accessibility of products and services.@en

Although a number of studies have reported that force feedback gravity wells can improve performance in "point-and-click" tasks, there have been few studies addressing issues surrounding the use of gravity wells for multiple on-screen targets. This paper investigates the performance of users, both with and without motion-impairments, in a "point-and-click" task when an undesired haptic distractor is present. The importance of distractor location is studied explicitly. Results showed that gravity wells can still improve times and error rates, even on occasions when the cursor is pulled into a distractor. The greatest improvement is seen for the most impaired users. In addition to traditional measures such as time and errors, performance is studied in terms of measures of cursor movement along a path. Two cursor measures, angular distribution and temporal components, are proposed and their ability to explain performance differences is explored.@en