Alan Dix on Usability Testing with Five Users16 Jun 2011
In his recent post, Are five users enough?, Alan Dix discusses how many users are actually needed for a usability test. Dix’s post begins by highlighting the origins of Jakob Nielsen’s five-users-per-iteration rule of thumb with links to Nielsen’s original research papers. The answer to the question is, of course, it depends on what one is conducting a usability test to find out. The remainder of Dix’s post discusses the number of users required for different types of usability tests, including formative and summative evaluations, hypothesis testing and qualitative studies.