Modeling and Interpretation Question for Interaction in LMER Output.
The modeling question regards my depiction of time. The amount of elapsed time between participants and testing points is not equal equal. Students in the same classroom will be measured at equal time points, but while one class might have 4 months in between testing, another class might have 7 months.
In lme, AIUI this would be comparing different correlation structures, as per the example for corCAR1().