If you haven’t found Seth’s Blog, I highly recommend it!  Seth Roberts, Ph.D., is a professor emeritus of psychology at the University of California at Berkeley.  He writes about a variety of topic, but has a great mind for statistics.  He often posts about statistics that are used incorrectly, by people who are usually considered experts in the field.  By reading about the incorrect uses and his related explanations, I am reminded to be wary of what I read, and it sharpens my ability to read research.

I particularly enjoyed a recent post titled “‘Baffling’ Link between Autism and Vinyl Floors”.  In fact I loved it so much that I sent the link to all of my nerdy statistics loving friends.  At first, it seems like an amazing break through… Scientific America writes that:

“Children who live in homes with vinyl floors, which can emit chemicals called phthalates, are more likely to have autism, according to research by Swedish and U.S. scientists published Monday.

The study of Swedish children is among the first to find an apparent connection between an environmental chemical and autism.”

Wow!  What a break though, right?  Maybe, but maybe not.  Seth points out some real weaknesses in the study’s methodology, including the often incorrect assumption that a large sample size is both necessary, and the most important aspect of research design.

So if you took statistics or research methods years ago, this is a great reminder about sound research methodology, and that even journals as prominent as Scientific America sometimes don’t get it 100% correct.