Cost-Justifying Usability, 2nd Edition

distinct from user errors during performance of tasks). Finally, we applied

the refined modeling technique to the models of the proposed application.

3. Compare modeling results to goals. Next, we compared the predicted produc-

tivity gains (or losses) of the proposed application relative to the existing

applications for each task with the productivity gain goals for each task.

4. Address unmet goals. For tasks in which the models predicted that productiv-

ity gain goals would not be met, we then analyzed the models in detail to

determine why and to help drive suggested redesign directions.

5. Run a productivity test on the proposed application. After ...