After reviewing a number of evidence-based research papers regarding a certain issue, we would be concerned about how to reach a conclusion that is the closest to the truth. The traditional literature review approach tends to be influenced by personal prejudice and perspective, and thus may be more susceptible to subjective judgments.
In addition, people often fall into the trap of pursuing p value < .05. An alternative approach, metaanalysis, uses statistical procedures to integrate findings from a collection of studies and form a synthetic conclusion. This article introduces the basic concepts and statistical procedures of meta-analysis, and reminds readers about the preparation for and the limitations of using meta-analysis. Some statistical concepts that are easily misunderstood are also clarified.