20 Meta-Analysis

Research Methods in Psychology


  1. Frank L. Schmidt PhD

Published Online: 26 SEP 2012

DOI: 10.1002/9781118133880.hop202020

Handbook of Psychology, Second Edition

Handbook of Psychology, Second Edition

How to Cite

Schmidt, F. L. 2012. Meta-Analysis. Handbook of Psychology, Second Edition. 2:IV:20.

Author Information

  1. University of Iowa, Tippie College of Business, Iowa City, Iowa, USA

Publication History

  1. Published Online: 26 SEP 2012


The small sample studies typical of psychological research produce seemingly contradictory results, and reliance on statistical significance tests causes study results to appear even more conflicting. Meta-analysis integrates the findings across such studies to reveal the simpler patterns of relations that underlie research literatures, thus providing a basis for theory development. Meta-analysis can correct for the distorting effects of sampling error, measurement error, and other artifacts that produce the illusion of conflicting findings. This chapter discusses these artifacts and the procedures used to correct for them. Different approaches to meta-analysis are discussed. Applications of meta-analysis in I/O psychology and other areas are discussed and evidence is presented that meta-analysis is transforming research in psychology. Meta-analysis has become almost ubiquitous. One indication of this is that, as of October 12, 2011, Google listed more than 9 million entries for meta-analysis.


  • meta-analysis;
  • research synthesis;
  • data analysis;
  • cumulative knowledge;
  • psychological theory