Clayton Lewis is a Professor of Computer Science, Fellow of the Institute of Cognitive Science, and Co-Director for Technology at the Coleman Institute for Cognitive Disabilities at the University of Colorado at Boulder. He is well known for his research on evaluation methods in user interface design. He has also contributed to cognitive assistive technology, to programming language design, to educational technology, and to cognitive theory in causal attribution and learning. He was inducted in 2009 into the ACM CHI Academy and was the winner of the 2011 ACM SIGCHI Social Impact Award.