Affiliations: [a] Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA, USA | [b] Human Engineering Research Labs, VA Pittsburgh Healthcare System, Pittsburgh, PA, USA | [c] Koester Performance Research, Ann Arbor, MI, USA | [d] AT Sciences, Pittsburgh, PA, USA
Correspondence:
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Address for correspondence: Richard Simpson, Forbes Tower, Suite 5044, University of Pittsburgh, Pittsburgh, PA 15260, USA. Tel.: +1 412 383 6593; Fax: +1 412 383 6597; E-mail: ris20@pitt.edu.
Abstract: The Input Device Agent (IDA) is being designed to improve computer access interventions for people with disabilities. This paper describes how IDA makes recommendations for scan period in row-column scanning systems and empirically evaluates the appropriateness of those recommendations. Two groups of subjects (8 people who were either able-bodied or had spinal cord injuries and 6 individuals with severe physical disability secondary to cerebral palsy) performed a single switch scanning task in four blocks of trials. In each trial, subjects were asked to select a target letter from a scanning matrix, using a single switch. Results suggest that IDA can recommend an appropriate fixed scan period for single switch scanning. In an absolute sense, participants' speed, accuracy, and subjective ratings in the IDA condition support this conclusion. In relative terms, participants' performance was at least as good for the IDA-selected scan period as for the self-selected scan period.
Keywords: Alternative computer access technology, one-switch row-column scanning, assessment
