As user experience professionals, we are often expected to assume multiple roles when evaluating products and systems. UX professionals are asked to measure user performance, identify issues and provide recommendations to them. The most challenging aspect is not determining that performance is poor; it is identifying the source of the poor performance in order to provide a design solution. Fortunately, many of the difficulties that users experience can be traced back to basic principles of cognitive science. Making design recommendations often requires that you understand the thought processes of users. In this panel discussion, three Cognitive Psychologists will demonstrate how fundamental principles of cognition can inform design solutions to many commonly occurring User Experience problems. We will review the latest advances in the measurement of user experience, including the measurement of implicit cognitive processes and how these affect user performance, and we will discuss how implicit assumptions by both users and designers often lead to user experience difficulties. The audience will learn key psychological principles that guide user experience and will have an opportunity to ask about the psychology behind common UX issues they encounter.