Rosnow, Ralph L.Rosenthal, Robert2014-02-192003Rosnow, Ralph, and Robert Rosenthal. 2003. "Effect Sizes for Experimenting Psychologists." Canadian Journal of Experimental Psychology 57, No. 3: 221-237.1196-1961http://nrs.harvard.edu/urn-3:HUL.InstRepos:11718222This article describes three families of effect size estimators and their use in situations of general and specific interest to experimenting psychologists. The situations discussed include both between- and within-group (repeated measures) designs. Also described is the counternull statistic, which is useful in preventing common errors of interpretation in null correlation (r-type) effect size indicators, but a wide variety of difference-type and ratio-type effect size estimators are also described.en-USJournal Article2014-01-13Robert Rosenthal and Ralph Rosnow