A method for evaluating research syntheses: The quality, conclusions, and consensus of 12 syntheses of the effects of after-school programs.

Like all forms of empirical inquiry, research syntheses can be carried out in ways that lead to more or less valid inferences about the phenomenon under study. This synthesis of syntheses (a) examined the methods employed in the syntheses of the effects of after-school programs (ASPs) and determined how closely they conformed to what is defined as best practice for research synthesis, (b) compared the inferences drawn from the ASP research literature by each synthesis with the inferences that plausibly could be made from the data they covered, and (c) determined the points of consistency across the syntheses with regard to both potentially valid and potentially invalid conclusions. It was found that the 12 syntheses used highly divergent methods, varying in problem definitions, search strategies, inclusion criteria for individual studies, and techniques for drawing conclusions about the cumulative evidence. Copyright © 2010 John Wiley & Sons, Ltd.