Usability engineering

Abstract

The essence of usability as a software development goal is that tools and systems can be designed to facilitate and enhance desirable experiences for their users-ease, transparency, engagement, fun, usefulness, self-efficacy, satisfaction-as well as to mitigate undesirable experiences, such as confusion, frustration, anger, disappointment, lack of confidence, and so forth. Usability is a nonfunctional requirement in that it describes the criteria for assessing the quality of a system beyond merely specifying the functions that the system performs, its functional requirements.