<<I'm serious.  Why do you think some research "counts" and other
research doesn't?>>


Study quality: is it randomized and controlled?, is the sample population
large enough?, is the study conducted over a long enough period of time? are
you measuring what you think you're measuring? (confounding variables...),
(in the case of an epidemiological study) is it prospective? (rather than
case control)?...

One of the first steps in a meta-analysis (study of studies) is to eliminate
studies of insufficient quality.  Often, this may mean eliminating well over
half of all published studies.  It may also mean tracking down unpublished
studies (often showing no effect).

I think that you answered your own question in a previous post.  Some
research doesn't count because of flawed design (or quality, if you prefer).
The results are also subject to misinterpretation (often,
overgeneralization).

Rob