Medical Term:

variance ratio


Definition: the distribution of the ratio of two independent estimates of the same variance from a gaussian distribution based on samples of sizes (n + 1) and (m + 1), respectively. Estimates are usually based on one such sample analyzed in such a way as to make them independent, analysis of variance, and F may be used to test a null hypothesis that the observed differences among sample means is no greater than could readily be accounted for by chance.