ABSTRACT
Hypothesis evaluated with test In a set of k independent samples (where k r 2), do at least two of the samples represent populations with different mean values?
Relevant background information on test The term analysis of variance (for which the acronym ANOVA is often employed) describes a group of inferential statistical procedures developed by the British statistician Sir Ronald Fisher. Analysis of variance procedures are employed to evaluate whether or not there is a difference between at least two means in a set of data for which two or more means can be computed. The test statistic computed for an analysis of variance is based on the F distribution (which is named after Fisher), which is a continuous theoretical probability distribution. A computed F value (commonly referred to as an F ratio) will always fall within the range 0 S F I a. As is the case with the t and chi-square distributions discussed earlier in the book, there are an infinite number of F distributions - each distribution being a hc t ion ofthe number of degrees of fieedom employed in the analysis (with degrees of fieedom being a h d i o n of both the number of samples and the number of subjects per sample). A more thorough discussion of the F distribution can be found in Section V and Endnote 1 1.
