Publication Bias

Abstract

Publication bias, defined as a “tendency for positive results to be overrepresented in the published literature,” was recognized and bemoaned as early as the 17th century by the chemist Robert Boyle. In the latter half of the 20th century, it began to be recognized as an increasingly serious scientific problem characterized by a deluge of positive published results (actually exceeded 95% in some areas of psychology). And, by the second decade of the 21st century, data mining techniques indicated that the phenomenon had reached epic proportions, not only in psychology and the other social sciences, but in many of the life and physical sciences as well: a finding that might have been viewed as an amusing idiosyncratic scientific fact of life if not for a concomitant realization that most of these positive scientific findings were wrong. And that publication bias, if not a cause of this debacle, was at least a major facilitator. This chapter provides documentation for the high prevalence of this odd phenomenon in a wide swath of myriad empirical scientific literatures along with the accompanying compulsion it fosters for producing positive rather than reproducible results.