Several times in the past few pages, we’ve emphasized the value of using different methods to study the same phenomenon. The advantage of this approach is that conclusions are most convincing when the results are the same regardless of method.

In reality, though, findings are often inconsis­tent. Suppose, for example, many researchers find that people often share personal information with friends (e. g., MySpace or Facebook), some research­ers find that people share occasionally with friends, and a few researchers find that people never share with friends. What results should we believe? What should we conclude? Meta-analysis allows research­ers to synthesize the results of many studies to estimate relations between variables (Becker, 2003). In con­ducting a meta-analysis, investigators find all studies published on a topic over a substantial period of time (e. g., 10 to 20 years), and then record and analyze the results and important methodological variables.

Thus, meta-analysis is a particularly power­ful tool because it allows scientists to determine whether a finding generalizes across many studies that used different methods. In addition, meta­analysis can reveal the impact of those different methods on results.

Integrating Findings from Different Studies

Studying Adult Development and Aging 27