ad Silicon Tails: An old discussion still going strong

Thursday, September 02, 2004

An old discussion still going strong

An old discussion still going strong: How many test persons do you need - Understanding Users

My good friend in Denmark, Thomas Snitker, recently posted a blog about how many users are needed in a usability test. Will this discussion never end........? In my mind a huge part of this discussion is completely misguided in that it applies quantitative validation criteria to what is essentially qualitative research. Usability testing (the typical lab version at least) is an exploratory methodology, and not one in which you need a specific number of people to learn something (at least typically - of course there are behavioral studies in which numbers matter, but it's not common in industry versions of usability testing). My colleague, Mike Katz, has actually written an interesting paper about why N=1 is often more than enough, unfortunately it's not published yet, but soon, I hope. Here's to small numbers and deep insights!