The Iron Law: The number of participants in the study should exceed the number of authors on the paper.
Yet I opened up the latest issue of the American Educational Research Journal to discover a violation of said rule in the article, “The Emotional Ambivalence of Socially Just Teaching: A Case Study of A Novice Urban Schoolteacher,” which has two authors. Got to love the “convenience sample” - the novice teacher is a former student of one of the authors. Jay Greene, I am totally going to dominate your bingo game with one article only.
No disrespect to qualitative research intended here - in fact, I believe qualitative research is critical to educational research and policy. But qualitative research comes in many flavors (as does quantitative research), and studies like this one do not help the cause.