Summary: Testing a small number of participants gives qualitative insights, which are great. But if 4 out of 5 test users do something, don't conclude that 80% of all users will do the same.
Raluca Budiu is Senior Director, Data Strategy, at Nielsen Norman Group, where she uses her data-analysis expertise to drive strategic decisions. She also serves as editor for the articles published on NNgroup.com. Raluca has coauthored many NN/g reports, as well as the book Mobile Usability. She holds a Ph.D. from Carnegie Mellon University.
