This week’s assignment was to create a justification for why we would recommend a small test group for a usability study for our business based on a scenario where we need to find usability issues with a limited budget and within a short timeframe due to an upcoming busy retail season expected by the business.
We based our justifications on the results of these studies, which we evaluated as our research for the week:
- Virzi, R. A. (1992). Refining the test phase of usability evaluation: how many subjects is enough? Human Factors, 34(4), 457-468.
- Eight is Not Enough. By Christine Perfetti and Lori Landesman (2001)
- Why You Only Need to Test with 5 Users. by Jakob Nielsen on March 19, 2000.
To summarize my justification: usability tests are not the same as market research. As usability researchers, we do not need to focus on statistical significance of our results, we need to focus on uncovering the most useful information from users within the constraints that come from working in the fast-paced world of corporate UXD work—limited timeframes and timeframes. This can often be done with as few as 3-10 users.