Variance Component Effects

Use this text field to specify effects defining sources of variability.

These effects are modeled to explain variability in the principal components. Variance components are estimated for each effect and then combined into a single pie chart of total variability in the principal components.

At least one variance component effect must be specified in order to produce results.

A residual variance component is also fitted that models all variability not accounted for by the effects.

For purposes of modeling additivity, all effects specified here are treated as rnadom effects, even though you might normally consider them to be fixed effects in an ANOVA analysis.

Effects typically contain one or more Cluster Significant Results, which must also be specified.

To Specify Variance Component Effects

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Type one or more effects in the text field.

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If you specify more than one effect, then you must separate the effects with spaces. For example, assuming A and B are listed as Cluster Significant Results, typing A B in the text field specifies variables A and B as main fixed effects.

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To specify interactions between effects, type an asterisk (*) between the effects. For example, assuming A and B are listed as Cluster Significant Results, typing A B A*B specifies variables A and B, and the interaction between A and B as effects.

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A vertical bar (|) can be used to create main effectsand interactions. For example, typing A|B is the same as typing A B A*B.

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An at-sign (@) can be used to limit the number of interactions. For example, typing A|B|C@2 removes the three-way interaction term.

Variance components modeling is not performed when With Variables are specified.