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Logo for the Journal of Rehab R&D
Volume 41 Number 5, September/October 2004
Pages 739 — 754

Usage, performance, and satisfaction outcomes for experienced users of automatic speech recognition

Heidi Horstmann Koester, PhD

Rehabilitation Engineering Research Center on Ergonomics, University of Michigan, Ann Arbor, MI
Abstract — This paper presents a variety of outcomes data from 24 experienced users of automatic speech recognition (ASR) as a means of computer access. To assess usage and satisfaction, we conducted an in-person survey interview. For those participants who had a choice of computer input methods, 48% reported using ASR for 25% or less of their computer tasks, while 37% used ASR for more than half of their computer tasks. Users' overall satisfaction with ASR was somewhat above neutral (averaging 63 out of 100), and the most important role for ASR was as a means of reducing upper-limb pain and fatigue. To measure user performance, we asked users to perform a series of word processing and operating system tasks with their ASR systems. For 18 of these users, performance without speech was also measured. The time for nontext tasks was significantly slower with speech (p < 0.05). The average rate for entering text was no different with or without speech. Text entry rate with speech varied widely, from 3 to 32 words per minute, as did recognition accuracy, from 72% to 94%. Users who had the best performance tended to be those who employed the best correction strategies while using ASR.
Key words: assistive technology, communication aids for disabled, computer access, outcomes, physical disability, speech recognition, user performance.

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