Some Statistical Methods for Combining Experimental Results

Advances in science and technology are generally the product of multiple investigations. This article discusses statistical methods for combining empirical results from a series of different experiments or clinical investigations. We delineate the steps an assessor might take in combining data from different studies and provide references for topics not discussed in detail. The article reviews some of the most commonly used statistical techniques for combining results in the medical and social sciences. The expressionmeta-analysisrefers to the practice of using statistical methods to combine the outcomes of a series of different experiments or investigations. The terminology arises because a meta-analysis uses a study as the unit of observation, and, thus, the data point for each study is itself a statistical summary based on an analysis of primary data.