Simeon Keates

Mouse movements of motion-impaired users: a submovement analysis

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.

Effect of age and Parkinson's disease on cursor positioning using a mouse

Point-and-click tasks are known to present difficulties to users with physical impairments, particularly motor- or vision-based, and to older adults. This paper presents the results of a study to quantify and understand the effects of age and impairment on the ability to perform such tasks. Results from four separate user groups are presented and compared using metrics that describe the features of the movements made. Distinct differences in behaviour between all of the user groups are observed and the reasons for those differences are discussed.

Developing steady clicks:: a method of cursor assistance for people with motor impairments

Slipping while clicking and accidental clicks are a source of errors for mouse users with motor impairments. The Steady Clicks assistance feature suppresses these errors by freezing the cursor during mouse clicks, preventing overlapping button presses and suppressing clicks made while the mouse is moving at a high velocity. Evaluation with eleven target users found that Steady Clicks enabled participants to select targets using significantly fewer attempts. Overall task performance times were significantly improved for the five participants with the highest slip rates. Blocking of overlapping and high velocity clicks also shows promise as an error filter. Nine participants preferred Steady Clicks to the unassisted condition. If used in conjunction with existing techniques for cursor positioning, all of the major sources of clicking errors observed in empirical studies would be addressed, enabling faster and more effective mouse use for those who currently struggle with the standard mouse.

Countering design exclusion: bridging the gap between usability and accessibility

It is known that many people are being excluded unnecessarily from using products, services and environments that are essential for supporting independence and quality of life. Such exclusion often arises from designers taking inadequate account of the end user’s functional capabilities when making design decisions. This paper addresses how traditional usability techniques can be extended to include accessibility issues by considering the spread of user functional capabilities across the population. A series of measures for evaluating the level of design exclusion based on those capabilities is also presented.

Universal access and assistive technology

This book contains the proceedings of the first Cambridge Workshop on Universal Access and Assistive Technology (CWUAAT), incorporating the fourth Cambridge Workshop on Rehabilitation Robotics, held in Cambridge, England in March 2002.

Improving web accessibility through an enhanced open-source browser

The accessibilityWorks project provides software enhancements to the MozillaTM, Web browser and allows users to control their browsing environment. Although Web accessibility standards specify markup that must be incorporated for Web pages to be accessible, these standards do not ensure a good experience for all Web users. This paper discusses user controls that facilitate a number of adaptations that can greatly increase the usability of Web pages for a diverse population of users. In addition to transformations that change page presentation, innovations are discussed that enable mouse and keyboard input correction as well as vision-based control for users unable to use their hands for computer input.

A submovement analysis of cursor trajectories

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.

Developing a practical inclusive interface design approach

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.

Cognitive and learning difficulties and how they affect access to IT systems

In October 2005, the IBM Human Ability and Accessibility Center and T.J. Watson Research Center hosted a symposium on “cognitive and learning difficulties and how they affect access to IT systems”. The central premise of the symposium was the recognition that cognitive and learning difficulties have a profound impact on a person’s ability to interact with information technology (IT) systems, but that little support is currently being offered by those systems. By bringing together internationally renowned experts from a variety of different, but complementary, research fields, the symposium aimed to provide a complete overview of the issues related to this topic. This paper summarises the discussions and findings of the symposium.

Defining Design Exclusion

It is known that many products are not accessible to large sections of the population. Designers instinctively focus on providing the necessary utility for someone with physical and skill capabilities similar to their own (Cooper, 1999), unless specifically instructed to do otherwise. They are either unaware of the needs of users with different capabilities, or do not know how to accommodate their needs into the design cycle.