Empirical research relevant to legal issues is common in other disciplines and is
once again growing more common in the legal academy. Such research, however,
varies widely in theoretical and methodological rigor and at times yields widely
different results. Such disparate findings may bring into question the usefulness of
such empirical research and may render it suspect in the eyes of practitioners,
courts, and policy makers. One approach to helping address such concerns as well
as other issues is meta-analysis-the quantitative, rather than simply narrative
review of empirical research. Meta-analysis synthesizes the relevant empirical
literature, statistically summarizing the results of all empirical work in a particular
area; and also identifies moderator variables, aspects of the various studies that
might have influenced their findings. In this Article, I explain the importance of the
meta-analytic approach, discussing what it is, why it is useful to members of the
legal system, and the straightforward way of conducting a meta-analysis. The
Article should be useful to legal academics, policy makers, courts, and
practitioners.