Function and Applicability
Mike Allen and Raymond W. Preiss
Meta-analysis provides a technique that allows researchers to aggregate data and summarize existing reports. The technique is used to reduce or eliminate various sources of artifact and statistical error. Additionally, meta-analysis provides an ability to examine the impact of various design issues and various theoretical possibilities. In this chapter, we explain what meta-analysis is and the justification for using the procedure. Our goal in this chapter is to enhance understanding of meta-analysis so that reading subsequent chapters is easier. The discussion does not consider a number of technical issues relating to the mathematical or methodological features of meta-analysis, as those discussions do exist and can be found in various textbooks dealing with meta-analysis (e.g., Cooper & Hedges, 1994; Hunter & Schmidt, 1990).
The problem in the social sciences is the use of statistical inference to make decisions about whether the experimental or survey results are not due to random chance. Consider the simple issue of determining whether a coin