Evaluation of the task-action grammar method for assessing learnability in user interface software

Many approaches to evaluation of user interfaces in HCI exist. Most methodologies evaluate prototypes through user testing. Since user testing is expensive and time consuming, other methods are sometimes applied before user testing. These other approaches aim to identify problems through expert evaluation techniques. In this paper we present a novel use of the TAG (Task-Action Grammar) method as an evaluation tool to identify learnability problems in a interface prior to user testing. We find that the TAG assessment method revealed problems related to inconsistency and conceptual complexity in a design.