Meta-Analysis

Meta-analysis is a statistical method that integrates the results of several independent studies considered to be “combinable.” It has become one of the major tools to integrate research findings in social and medical sciences in general and in education and psychology in particular. Although the history of meta-analytic procedures goes all the way back [Page 794]to the early 1900s and the work of Karl Pearson and others, who devised statistical tools to compare studies from different samples, Gene V. Glass coined the term in 1976. Glass, Barry McGaw, and Mary Lee Smith described the essential characteristics of meta-analysis as follows:

• It is undeniably quantitative, that is, it uses numbers and statistical methods for organizing and extracting information.
• It does not prejudge research findings in terms of research ...