Model-based Evaluation

This chapter will first argue that model-based evaluation is a valuable supplement to conventional usability evaluation, and then survey the current approaches for performing model-based evaluation. Because of the considerable technical detail involved in applying model-based evaluation techniques, this chapter cannot include “how to” guides on the specific modeling methods, but they are all well documented elsewhere. Instead, this chapter will present several high-level issues in constructing and using models for interface evaluation, and comment on the current approaches in the context of those issues. This will assist the reader in deciding whether to apply a model-based technique, which one to use, what problems to avoid, and what benefits to expect. Somewhat more detail will be presented about one form of model-based evaluation, GOMS models, which is a well-developed, relatively simple and “ready to use” methodology applicable to many interface design problems. A set of concluding recommendations will summarize the practical advice.