7.2 Analytic Methods

It is not necessary to observe or interview users to evaluate an interactive application. Claims analysis is an analytic method that has been described and illustrated extensively in this book. In this method, the usability engineer identifies significant features in a design and generates hypotheses about the consequences these features might have for users engaged in activities (scenarios). A claims analysis is most often implemented for formative goals to better understand and guide a system's redesign. However, a refined set of claims can be also be used for summative goals the design rationale provides one view of how well a system meets users' needs.

An important motivation for analytic methods is that they can be used early in a development process, well before there are users or prototypes available for empirical tests. Another motivation is cost: It is often less expensive to analyze a system than to design and carry out an empirical study. As we have seen, analytic evaluation also guides empirical studies by identifying controversial or novel design features. It helps evaluators know what to attend to, what to measure, and what hypotheses to test.

A hazard of analytic evaluation is that designers may feel that they are being evaluated. Presumably, the design they produce is their best effort, given organizational constraints. Every problem identified or every downside can be heard as criticism. While such a personal reaction is understandable, it is unprofessional. Colleagues, especially usability engineers, can help designers by promoting a cooperative atmosphere...