Just read Bruce Macfalane's article in the latest edition of Teaching in Higher Education. His opening paragraph gets to the heart of his argument, so I will quote  it in full:

There is an increasing tendency for research to be divided into two types: ‘subjectbased’ research and ‘pedagogic’ research. Subject-based research is serious, scholarly and well-respected stuff. It is published in prestigious subject-based journals. This kind of research is what counts in the assessment of research quality in countries like the UK, Australia and New Zealand. Then there is ‘pedagogic’ research. This is where academics from various disciplines do research about their own teaching, that of others or focus on the way students learn. Sometimes, ‘research about learning and teaching’ is the phrase used to distinguish this type of scholarly endeavour from everything else in academic life. But apparently, unlike subject-based research, ‘pedagogic’ research is not ‘proper’ research (p.127).

I liked this article and can't really find anything to disagree with. I have long wondered what makes Boyer's Scholarship of Teaching and Learning a somewhat different type of scholarship  to his other three scholarships --moreover why have so many pedagogic researcher accepted this? Why is pedagogic research seen as somehow second rate? Why is it seen as easier? Like most people who have done pedagogic research I have also done non-pedagogic research (or 'proper' research) as some might call it.  Both use social science research methods. Neither is intrinsically more difficult or more scholarly than the other.

Reference

Bruce Macfarlane, “Prizes, pedagogic research and teaching professors: lowering the status of teaching and learning through bifurcation,” Teaching in Higher Education 16, no. 1 (2011): 127-130