What If There Isn’t a Single Effect Size? Implications for Power Calculations, Hypothesis Testing, Confidence Intervals and Replications

[From the working paper “The Unappreciated Heterogeneity of Effect Sizes:Implications for Power, Precision, Planning of Research, and Replication” by David Kenny and Charles Judd, posted at Open Science Framework (OSF)] “The goal of this article is to examine the implications…