Questions for meta-analysis.

In spite of an abundance of data, the empirical evidence as yet does not make clear whether meta-analysis will bring about progress in psychological science. Therefore, it is still useful and desirable to engage in rational analysis of the methodology. Such analysis is done in the present essay by posing five questions that go to the logical and conceptual foundation of meta-analysis. The questions are (a) What are the grounds for believing that the review of the literature, even a quantitative one, will bring about scientific discovery? (b) Why is the individual study devalued when the history of successful science seems largely the story of the success of the individual study? (c) What is the rationale for believing that data analysis by itself can markedly improve the fortunes of psychological science? (d) Is there a basis for claims made on behalf of meta-analysis that it is more accurate than either the traditional literature review or the individual study? (e) Is there justification for the claim that de facto meta-analysis has been used effectively in physical science?