> is it common to work with so small sample sizes in psychology?
Yes. Even much smaller sample sizes are common. I've seen "results" published in supposedly reputable journals with sample sizes as small as 9. Not 9 other studies that were meta-analyzed, mind you. 9 individual people.
This is just one of several reasons why most of psychology is junk science, if not outright fraudulent. Statistical methods is usually a required course for students in such disciplines, so I do not buy the "they don't know better" excuse. Not that you need to know statistics in order to understand that you can't conclude anything from a sample size of 9.
Yes. Even much smaller sample sizes are common. I've seen "results" published in supposedly reputable journals with sample sizes as small as 9. Not 9 other studies that were meta-analyzed, mind you. 9 individual people.
This is just one of several reasons why most of psychology is junk science, if not outright fraudulent. Statistical methods is usually a required course for students in such disciplines, so I do not buy the "they don't know better" excuse. Not that you need to know statistics in order to understand that you can't conclude anything from a sample size of 9.