Post hoc comparisons

One of the features that makes one-way ANOVA a valuable procedure is the option to include post hoc multiple comparisons using a variety of statistical tests. These multiple comparisons make it possible to find the groups that differ from each other, and those that form homogenous subsets within a larger pool of groups.

The post hoc dialog shown in the following figure has 14 choices associated with equal variances, and four for unequal variances. You can choose several and compare the results to check their agreement in terms of the differences they find significant. In this example, the Scheffe, Tukey, Dunnett, and Tamhane's T2 tests are selected. By default, the Dunnett-test uses the last group of the independent factor ...

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