释义 |
ANOVA``Analysis of Variance.'' A Statistical Test for heterogeneity of Means by analysis of groupVariances. To apply the test, assume random sampling of a variate with equalVariances, independent errors, and a Normal Distribution. Let be the number ofReplicates (sets of identical observations) within each of Factor Levels(treatment groups), and be the th observation within Factor Level . Also assume that the ANOVA is ``balanced'' by restricting to be the same for each Factor Level.
Now define the sum of square terms
which are the total, treatment, and error sums of squares. Here, is the mean of observations within FactorLevel , and is the ``group'' mean (i.e., mean of means). Compute the entries in the following table,obtaining the P-Value corresponding to the calculated F-Ratio of themean squared values
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Category | SS | °Freedom | Mean Squared | F-Ratio"> F-Ratio | Treatment | SSA |  |  |  | Error | SSE |  |  | | Total | SST |  |  | |
If the P-Value is small, reject the Null Hypothesis that all Means are the same for thedifferent groups. See also Factor Level,Replicate, Variance |