Wednesday, July 04, 2007

Selection bias in journal articles

Journals dealing in psycholinguistic research do not publish null results generally, because they are "inconclusive". So it's completely possible that out of 100 experiments, 95 are inconclusive, and 5 are "significant", but that all five are Type I errors. But it's those 5 experiments that will get published.

The naive rebuttal to this would be that such a situation would only rarely arise. But the non-obvious thing is that rare events do happen. If we published only those five articles, then how would we draw the conclusion that we are not in Type I la la land?