This paper presents a new methodology for performing theory-based evaluations of user
interface designs early in the design cycle. The methodology is an adaptation of the design
walkthrough techniques that have been used for many years in the software engineering
community. Traditional walkthroughs involve hand simulation of sections of code to ensure
that they implement specified functionality. The method we present involves hand simulation
of the cognitive activities of a user, to ensure that the user can easily learn to perform tasks …