Wonil Hwang & Gavriel Salvendy (2010)
Communications of the ACM, 53(5), 130-133.
DOI: https://doi.org/10.1145/1735223.1735255
Abstract. Hwang and Salvendy's "10±2 rule" — meta-analytic refinement of Nielsen's "5 users find 85%" claim, arguing that 10±2 evaluators is the right target for heuristic evaluation while 5±2 users remains right for usability testing. Frequently cited refinement of discount-usability sizing.
Tags: heuristic-evaluation sample-size