The Control Group and Meta-Analysis

Abstract

Social scientists use a mixture of different methodologies, which creates problems for researchers attempting to review the cumulative results of all studies. Standard practice for review studies using meta-analysis is to adjust the findings of all studies that use control groups and to include studies not having control groups without adjustment for extraneous effects, or to not use studies that lack a control group, which could produce an erroneous result. Our study develops a novel meta-analytic procedure that combines the evidence on control group change with evidence on change from the intervention, making it possible to adjust for the effects of extraneous factors in all studies and bridges the gap between control group studies and other types of studies.