Promoting replicability in developmental research through meta-analyses: Insights from language acquisition research
Bergmann, C., Tsuji, S., Piccinini, P. E., Lewis, M. L., Braginsky, M. B., Frank, M. C., & Cristia, A.
Promoting replicability in developmental research through meta-analyses: Insights from language acquisition research. Child Development, 89
(6), 1996-2009. doi:10.1111/cdev.13079.
Previous work suggests key factors for replicability, a necessary feature for theory
building, include statistical power and appropriate research planning. These factors are examined by analyzing a collection of 12 standardized meta-analyses on language development between birth and 5 years. With a median effect size of Cohen's d= 0.45 and typical sample size of 18 participants, most research is underpowered (range: 6%-99%;
median 44%); and calculating power based on seminal publications is not a suitable strategy.
Method choice can be improved, as shown in analyses on exclusion rates and effect size as a
function of method. The article ends with a discussion on how to increase replicability in both language acquisition studies specifically and developmental research more generally.