Clayton Lewis, PhD, is professor of computer science and fellow of the Institute of Cognitive Science at the University of Colorado. He is well known for his work (with students and colleagues) on evaluation methods in user interface design, including the thinking aloud and cognitive walkthrough methods. His work on technology for people with cognitive disabilities has been presented to the U.S. Access Board Technical Advisory Committee, CSUN, RESNA, ACM ASSETS, and to other forums. Lewis has served previously as Scientist in Residence for the Coleman Institute, as Fellow of the Hanse-Wissenschaftskolleg (Delmenhorst, Germany), as technology advisor to the director of the National Institute for Disability and Rehabilitation Research, and as Visiting Advisor to DIAGRAM Center, a nonprofit organization dedicated to enhancing the availability of learning materials for students with disabilities. He has been honored by appointment to the ACM SIGCHI Academy, by the SIGCHI Social Impact Award, and by the Strache Leadership Award (CSUN Assistive Technology Conference). Lewis received his PhD in experimental psychology from the University of Michigan.