Subjective literature reviews suffer selection biases that meta-analysis avoids.

Evidence

Moreover, none of the previous reviews used fully quantitative assessments of contact effects. Instead, authors of past reviews have tended to offer subjective judgments of the contact–prejudice relationship that are based on their own readings of a subset of the research literature. Although this approach can be useful, selection biases and differing interpretations of the literature limit the ability to reach definitive conclusions about contact’s effects. Thus, quantitative approaches to research synthesis are preferred, as they provide a means for examining replicable patterns of effects across the full accumulation of relevant studies (Johnson & Eagly, 2000; Rosenthal, 1991). — Thomas F. Pettigrew, Linda R. Tropp, A Meta-Analytic Test of Intergroup…, 28

Categorization

• XREF: Connects to general epistemology of research synthesis and how review methods shape scientific conclusions. — connects to: A meta-analysis synthesized 515 studies with 250,089 participants across 38 nations. — Thomas F. Pettigrew, Linda R. Tropp, A Meta-Analytic Test of Intergroup…, 30

Related

• A meta-analysis synthesized 515 studies with 250,089 participants across 38 nations. (similarity 0.88)
• No meta-analysis of intergroup contact research existed before this study. (similarity 0.87)
• Prior contact research reviews each covered fewer than 60 studies. (similarity 0.87)
• Meta-analyses overestimate effect sizes because null results go unpublished. (similarity 0.85)
• Stronger contact effects in rigorous studies would confirm the contact-prejudice link. (similarity 0.85)
• Meta-analysis pools all studies to estimate effect sizes and moderators (similarity 0.85)
• Random effects meta-analysis suits heterogeneous literatures with ill-specified treatments (similarity 0.83)
• The contact-prejudice effect may be partly an artifact of publication bias. (similarity 0.82)
• More rigorous contact studies show larger prejudice-reduction effects. (similarity 0.82)
• Contact studies with cleaner control groups show larger effects. (similarity 0.81)
• Contact’s prejudice-reducing effect is causal, not a selection or publication artifact. (similarity 0.80)
• Comparing published and unpublished studies tests whether reporting bias inflates effects. (similarity 0.80)
• Theorists now seek what is necessary, not just helpful, for contact success (similarity 0.80)
• Participant selection bias does not inflate contact-prejudice effect sizes. (similarity 0.79)
• Randomized contact experiments yield near-large prejudice reduction effects. (similarity 0.79)