In this case he has been very explicit about the number and types of people in the study. From the article: "In total, 16 iPad users participated in the new st

In this case he has been very explicit about the number and types of people in the study. From the article: "In total, 16 iPad users participated in the new study. Half were men, half were women. The age distribution was fairly even for 14 users between the ages of 21–50 years; we also had 2 users older than 50. Occupations spanned the gamut, from personal chef to realtor to vice president of human resources. " I think the key is not to think in terms of 'statistically significant' as in a formal scientific study of a single fact, but in terms of 'useful feedback from real users.'