後設分析 (Meta-Analysis)

Overview

Meta-analysis statistically combines effect sizes from multiple independent studies to produce a pooled estimate with greater precision and generalizability. It quantifies between-study heterogeneity and tests for publication bias, providing a rigorous evidence synthesis that goes beyond narrative literature reviews.

When to Use

• Synthesizing quantitative findings from multiple studies on the same research question
• Resolving conflicting results across studies
• Estimating an overall effect size with tighter confidence intervals
• Identifying moderators that explain heterogeneity across studies

When NOT to Use

• Studies are too heterogeneous in constructs, measures, or populations to combine meaningfully
• Fewer than 5 studies are available (pooled estimates become unreliable)
• Primary studies have fundamentally different research designs (mixing RCTs with observational)
• The research question is qualitative or conceptual rather than quantitative