I have 12 data points (T1-T12) and would like to model for potential cubic growth in GMM. I managed to fit a decent linear and quadratic growth models but am unclear on to determine the appropriate times in the syntax for a cubic model:
Thanks for the quick response. Can you clarify exactly what you mean though. As shown in my initial post I already have four growth factors listed (i s q cub) before the "|" symbol, but I am unclear on what I should list after the "@" symbol for each of the 12 time points. Thank you for your explanation.
You list the linear time scores after the | symbol. I just noticed you did this incorrectly for the quadratic model. The time scores are always the linear and Mplus computes the others. Keep the on a small scale like 0 .1 .2 etc.