Model Diagnostic, Adequacy & Data Quality Check
One-Way Random-Effects Model
The diagnostic analysis is the same for both fixed and random effects models as the assumptions for the error term stays the same (identical, independent, and normally distributed). Figure 8, Figure 9, and Figure 10 show no concerns of violations for any of the assumptions.
Figure 8. Plot of Residual vs Fitted Value
Figure 9. Plot of Residual vs Observation Order or Time
Figure 10. Normal Probability Plot (pp-plot)