Which of the following statistical procedures systematically combines data from multiple studies that focus on the same question and use similar variables?

• A. Regression analysis
• B. ANOVA
• C. Meta-analysis
• D. Factor analysis

Answer: (C)

Meta-analysis is designed to synthesize evidence by systematically combining results from multiple studies that address the same question and use similar variables. By converting study findings into a common metric (an effect size) and pooling these estimates, it gives a single, overall picture of the effect while accounting for how precise each study is. This approach increases statistical power, helps determine whether effects are consistent across different samples or settings, and can explore sources of variability between studies through subgroup analyses or meta-regression.

In contrast, regression analysis examines relationships between variables within one dataset, estimating how a predictor relates to an outcome. ANOVA compares group means within a single study to see if there are differences among groups. Factor analysis looks for underlying latent factors that explain patterns of correlations among observed variables within a single dataset. None of these methods inherently combine results across independent studies the way meta-analysis does.