Notes on verification

Well-corroborated by multiple peer-reviewed studies and reviews, including meta-analytic evidence, though effect sizes vary across individual studies. [tier=gold indep_score=1.0 clusters=5 claim_tier=notable | framework convergence=partial (upstreams: Walker et al. 2002, Smith & MacNeill 1994, Korman et al. 2003) — publishers independent, evidence may not be | kind=empirical eligibility=high (extractor: attributed/medium)]