Meta-Analysis: Motivation and Limitations

Meta-analysis serves as a critical tool for appraising entire bodies of evidence, addressing the fact that the scientific process does not automatically optimize outcomes despite the abundance of published research. A key component is between-study heterogeneity, which describes how true effect sizes vary. The random-effects model utilizes τ 2 to quantify this variance, enabling the calculation of a pooled effect. High heterogeneity often indicates the presence of multiple subgroups with differing true effects within the data.