What is usability evaluation?

There are numerous methods that can be used to evaluate the usability of a digital library. Usability evaluation methods can be classified as belonging to one of three categories: inspection, testing, and inquiry.

Usability “inspection” refers to a number of processes whereby experts systematically review the usability of a digital library and recommend improvements. Two such processes are described below: heuristic evaluation and cognitive walkthrough.

Usability “testing” refers to evaluative processes whereby the interface that enables human-computer interactions are systematically tested and enhanced. Usability testing can be done in a professional usability laboratory, locally using a portable usability lab, or even with standard video equipment. Typically, usability testing involves having people follow predetermined protocols so that specific aspects of a digital library's usability can be evaluated. The “think aloud” approach to usability testing is described below in more detail.

Usability “inquiry” refers to processes that are somewhat like usability testing, except that in usability inquiry evaluators observe users working with digital libraries while doing real work rather than evaluator-assigned tasks. There are a number of evaluative methods that fit within the usability inquiry framework including: field observations, focus groups, interviews, use logs, and questionnaires.