Variance Analysis

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Variance Analysis

Variance Analysis is a convenience script for comparing three or four groups. It first applies the Bartlett test to establish, whether the group variances are equal. If yes, it proposes one-way ANOVA for testing for significant differences between the group means. Otherwise, the non-parametric Kruskal-Wallis test is proposed for testing whether the distributions are identical.

Variance Analysis Configuration

The Variance Analysis configuration window is illustrated below.

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Up to four groups can be compared, according to the Type selection

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If Merge columns is enabled, the data of all columns will be pooled, otherwise the test is performed between the respective columns of the aggregates.

With the One aggregate - columns as groups setting it is assumed that the groups to be compared are arranged as columns in a single aggregate.

Variance Analysis Results

As a first step, the Bartlett Test is applied for comparing the variances, and the result shown.

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Depending on the outcome, ANOVA or Kruskal-Wallis are proposed as the follow-up test, but both are available. When applying either test as the second step, the results correspond to that of the individual test.