Quote Originally Posted by Fuchs View Post
That would be statistically totally insignificant and irrelevant, though. You need statistical significance to find a correlation - otherwise you're merely discussing a random result.

Few serious people will consider a study interesting if it lacks statistical relevance.

He can formulate a hypothesis, of course. He just cannot test it properly without obeying basic statistical principles. Anecdotical evidence can easily be countered with conflicting anecdotical evidence - which means that anecdotical evidence is useless.
I myself uphold the double blind study as the Gold Standard in research design, but I still think the case study has its uses. Human social life rarely unfolds in a double blind fashion, after all!