Usability (Testing) Metrics. Tullis and Albert, the authors of the text, Measuring the User Experience, dedicate the majority of their book to metrics – from definition and types to use and measurement. A metric is commonly defined as “a way of measuring or evaluating a particular phenomenon or thing” (p. 7). Usability (testing) metrics involve (1) a user, (2) doing something, (3) with a product, system or other thing (p.4). Building on classmate Judith Stevenson’s 1 March 2010 Design + Research article on Usability Testing, metrics and their measurement provide tools and results for determining design and development effectiveness, tracking design progress, providing insights and influencing decision-makers. Metrics replace hunches and feelings with facts. Usability metrics and their measurement can show improvement, decline or indifference (i.e., no change) in a user’s experience with an updated, improved or changed product or process (p. 9).
Their text provides an excellent article (p. 10 – 13) debunking ten common myths about usability metrics including issues concerning time requirements, costs, ineffectiveness at determining causes, conflicts with gut feelings, misunderstandings by management and difficulties with small sample sizes. Usability metrics can:
- be cost and time effective,
- address a wide variety of issues and products of any size and
- be understood and appreciated by management