Information Criteria

Figure 1. Information criteria for compound symmetry covariance model
Information criteria for compound symmetry covariance model

The -2 Restricted Log Likelihood is slightly larger for the compound symmetry model, but that's because the unstructured model is more complex. The other information criteria are larger for the unstructured model, suggesting that the compound symmetry variance structure is more appropriate. It's probably safe to assume that the variances remained constant from one measurement time to the next, but you can also compute a likelihood ratio test of the equal variances hypothesis.

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