...Brendan A. Schuetze; Veronica X. Yan; Chris Aberson In this experiment, we recruited 261 psychology faculty to determine the extent to which they were able to visually estimate the overlap of two distributions given a Cohen’s d effect size; and vice-versa estimate d given two distributions...

...Elizabeth Collins; Roger Watt; Chris Aberson Statistical power is key to planning studies if understood and used correctly. Power is the probability of obtaining a statistically significant p-value, given a set alpha, sample size, and population effect size. The literature suggests that psychology...

...Zoltan Dienes; Don van Ravenzwaaij Obtaining evidence that something does not exist requires knowing how big it would be were it to exist. Testing a theory that predicts an effect thus entails specifying the range of effect sizes consistent with the theory, in order to know when the evidence counts...

...Don C. Zhang; Jonathan Wai Research evidence in the social sciences often relies on effect size statistics, which are hard to understand for the public and do not always provide clear information for decision-makers. One area where interpretation of research evidence has profound effects on policy...

.../ . multiple linear regression R-squared amount of variance explained effect size Multiple linear regression is one of the most used analysis methods within psychological research. The R-Squared ( R 2 ) value is commonly reported when performing multiple linear regression. It quantifies...

... nonsignificant results. Simulations show that the adapted Fisher method generally is a powerful method to detect false negatives. We examined evidence for false negatives in the psychology literature in three applications of the adapted Fisher method. These applications indicate that (i) the observed effect size...