Forum: connections

XIII.3 May + June 2006
Page: 14
Digital Citation

HCI and cognitive disabilities

Clayton Lewis

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More and more HCI professionals are working on increasing access to computing systems for people with disabilities, as can be attested by participation in the lively ASSETS conferences of ACM's SIGACCESS (Special Interest Group on Accessible Computing). Technology for people with cognitive disabilities—from mental retardation and developmental disabilities, brain injury, stroke, effects of aging, or severe mental illness—is an area in which activity is growing especially rapidly. And the need is great: While good world data is not available, it's a reasonable estimate that as many as 400 million people worldwide suffer from these conditions.

While public attitudes are improving, and integration into society of people with cognitive disabilities is increasing, there is still widespread ignorance about them and how technology can be of value to them. Mary Hart's paper at ASSETS 2005 described the success of five students with autism, with moderate to mild mental retardation, in a high school level Excel curriculum [1]. All of these students were excluded under existing policy from regular computer courses in their schools, but clearly they are able to benefit from the opportunity to work with computers.

As computers become smaller, cheaper, and more powerful, new opportunities in assistive technology emerge. Handheld computers can help people who have difficulty remembering a schedule, or the steps in work or daily life routines. Such difficulties are a common effect of brain injuries. In some cases, commercial scheduling applications can be used, and in other cases special prompting applications, such as those developed by AbleLink Technologies (, can deliver pictorial or spoken reminders.

Many people with cognitive disabilities also have difficulties speaking and use augmentative and alternative communication (AAC) devices, in which a computer allows them to control synthetic speech output, often using selection pictorial symbols as input. Motor difficulties are also common for people with cognitive disabilities, so AAC devices often support special interaction techniques, such as switch scanning, in which candidate symbols are presented in sequence, and the user makes a selection action when the needed symbol is presented.

On the Web, work to make key information accessible to people with restricted literacy is increasing. The site is a Medicaid reference in the US that presents information about government assistance programs for people with cognitive disabilities. For some items this site offers spoken presentation of the same material, with video of the speaker, a person with a cognitive disability. The editorial team that produces the materials for includes a self-advocate, one of a growing number of people with cognitive disabilities who are acting as public activists in promoting the interests of people with disabilities.

Email has become a vital tool for all kinds of people. An international collaboration based at the University of Oregon has developed email interfaces that people with cognitive disabilities can use ( Such design challenges push us to extend our design methods in interesting and useful directions.

Cognitive disabilities are complex and variable, and the research challenges of understanding them, and understanding how to combat or compensate for their effects, are profound. But a number of promising initiatives can be identified for HCI researchers and developers. One is the application of natural language technology: This is making huge strides, and automated summarization tools will soon be within reach, if we work on them.

Reducing clutter and complexity of user interfaces is another area that can repay research. People with cognitive disabilities sometimes have trouble maintaining focus and making choices from crowded screens. Recent versions of Sun's Solaris operating system use the reflection capabilities of its Java implementation to allow all user interface controls to be extracted and re-presented. Can we build on this idea to allow the user interface of an application or application suite to be restructured without reimplementation so as to decrease the number of controls exposed on a given screen, increasing the depth of the interface to allow its breadth to be decreased? Configurable toolbars for complex operations are steps in this direction. Is there a cleaner architectural approach? Can we smoothly shift focus within a complex application so as to expose particular functionality with minimal clutter from other functions?

How about increasing the flexibility and power of nonverbal communication for people with impaired language capability? Intriguing work in Sweden is exploring how the ability to capture, store, and manage large quantities of digital images is opening up new ways to communicate with pictures [2].

A prominent theme in the accessibility world is universal design: the effort to design systems that work for a very wide range of users. In the examples above you can see how this works. We will all benefit if it becomes easier to produce easy-to-read summaries of complex texts, or if we can easily control user interface structures. Greater understanding of nonverbal communication may offer new expressive power for everyone.

While public attitudes are improving, and integration into society of people with cognitive disabilities is increasing, there is still widespread ignorance about them and how technology can be of value to them.

There is another kind of initiative in which HCI people can participate: Include people with cognitive disabilities in your studies. They are severely underrepresented today in usability test panels and as participants in HCI research studies. Indeed, all people with disabilities are underrepresented, but people with cognitive disabilities are even more so than others. Efforts to redress this situation will pay big dividends. Inclusion of people with cognitive disabilities will promote innovation and will increase our knowledge of, and our ability to support, a large and important group of people.

If you are interested in learning more about technology for people with cognitive disabilities, a good first stop on the Web is, describing the Rehabilitiation Engineering Research Center on Advancing Cognitive Technologies. RERC-ACT is the first US government-sponsored research center to focus on people's needs with cognitive technologies, with participation from more than a dozen academic, industrial, and institutional partners. One of the center's functions is to promote cooperation among mainstream technologists, assistive technologists, and researchers. Maybe you are in the mix!

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1. 2005 Hart, M. Autism/Excel study. In Proc. ASSETS 2005 (Seventh International ACM SIGACCESS Conference on Computers and Accessibility) New York: ACM, pp. 136-141.

2. 2001 Danielsson, H. and Jönsson, B. Pictures as Language. International Conference on Language and Visualisation, Stockholm, Sweden, November 8 - 9.

back to top  Author

Clayton Lewis
University of Colorado

About the Author:

Clayton Lewis is scientist in residence at the Coleman Institute for Cognitive Disabilities, and professor of computer science at the University of Colorado, Boulder, USA. He is a longtime participant in the HCI research community, with contributions in particular to widely used user-interface evaluation methods (thinking aloud and the cognitive walkthrough). He served as technical program cochair for CHI'89 and CHI'95.

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