Clayton Lewis is Emeritus Professor of Computer Science at the University of Colorado Boulder. Lewis served previously as Co-Director for Technology for the Coleman Institute for Cognitive Disabilities, and Fellow of the Institute of Cognitive Science, at CU, and as technology advisor to the director of the National Institute for Disability and Rehabilitation Research, US Department of Education. He is well known for his research on evaluation methods in user interface design. Two methods to which he and his colleagues have contributed, the thinking aloud method and the cognitive walkthrough, are in regular use in software development organizations around the world. He has also contributed to cognitive assistive technology, to programming language design, to educational technology, and to cognitive theory in causal attribution and learning.

Before joining the University of Colorado, Lewis was Manager of Human Factors at IBM’s Watson Research Center, where he was a member of the research staff from 1970 to 1973 and 1979 to 1984. He holds degrees from Princeton, MIT, and the University of Michigan. He has been honored by appointment to the ACM SIGCHI Academy, by the SIGCHI Social Impact Award, by the Strache Leadership Award (CSUN Assistive Technology Conference), and by the ACM SIGACCESS Outstanding Contribution Award.