Usability testing: is the whole test greater than the sum of its parts?

Usability testing is often employed to evaluate specific problem areas in a user interface. In this approach, users perform tasks that address the specific issues of concern. Use of the feature in isolation is assumed to provide results that would be valid if the features were used in the context of all other features. The present poster evaluates this assumption and describes the importance of an integrated approach to testing. We suggest that usability testers should construct test scenarios that require integration across different system features to obtain an accurate evaluation of the product and the individual features.