We typically recommend small sample sizes (5–10) for conducting iterative usability testing meant to find and fix problems (formative evaluations). For benchmark or comparative studies, where the focus is on detecting differences or estimating population parameters (summative evaluations), we recommend using larger sample sizes (20–100+). Usability testing can be used to uncover problems and assess the
UX benchmarking is an effective method for understanding how people use and think about an interface, whether it’s for a website, software, or mobile app. Benchmarking becomes an essential part of a plan to systematically improve the user experience. A lot is involved in conducting an effective benchmark. I’m covering many of the details in
Most usability testing involves finding and fixing problems as part of an iterative design process to make an interface more usable. It is typically called a Formative Usability Evaluation. In contrast, a Summative Usability Evaluation describes the current usability of an interface—as measured by things like task times, completion rates and satisfaction scores. Summative tells
