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Which is better RM ANOVA or mixed model?
While mixed models can treat those as true numbers and incorporate the different spacing of the weeks, RM ANOVA can’t. Repeated measures ANOVA falls apart when repeats are unbalanced. For example, a common design is to observe behaviors of different types, then compare them.
Can you compare model 1 to model 2?
While you can compare model 1 and model 2, and choose among them by ordinary likelihood ratio tests or F tests (e.g. anova in R), you cannot compare model 1 with 3 or model 2 with 3 by likelihood ratio tests or F tests. Nor you can compare 1 vs 3 and 2 vs 3 by information criteria, as the response variables are on different scales.
When to use repeated measures in mixed model?
As implied above, mixed models do a much better job of handling missing data. Repeated measures ANOVA can only use listwise deletion, which can cause bias and reduce power substantially. So use repeated measures only when missing data is minimal.
What do you need to know about mixed effect modeling?
Below are some important terms to know for understanding the statistical concepts used in mixed models: Crossed designs refer to the within-subject variables (i.e. timepoint, condition, etc.). Crossed designs occur when multiple measurements are associated with multiple grouping variables.
What’s the p-value of the 3rd ANOVA?
However, using the p-value in the 3rd anova, the model “modelRec” is significantly different form model “modelGen” at α = 0.1. Check out ANOVA for Linear Model Fits as well.
When to use repeated measures in ANOVA model?
Repeated measures ANOVA can only use listwise deletion, which can cause bias and reduce power substantially. So use repeated measures only when missing data is minimal. Repeated measures ANOVA can only treat a repeat as a categorical factor.
How to compare two models using ANOVA ( ) function?
For example, in the 1st anova that you used, the p-value of the test is 0.82. It means that the fitted model “modelAdd” is not significantly different from modelGen at the level of α = 0.05. However, using the p-value in the 3rd anova, the model “modelRec” is significantly different form model “modelGen” at α = 0.1.