Counternull (Paperback)

High Quality Content by WIKIPEDIA articles! In statistics, and especially in the statistical analysis of psychological data, the counternull is a statistic used to aid the understanding and presentation of research results. It revolves around the effect size, which is the mean magnitude of some effect divided by the standard deviation. The counternull value is the effect size that is just as well supported by the data as the null hypothesis. In particular, when results are drawn from a distribution that is symmetrical about its mean, the counternull value is exactly twice the observed effect size.