Considering the repeated design studying the effects of the student factors (N) affecting academic achievement (DV), the structure of which can be a) a single measure of IV and DV, b) a single measure of IV and multiple measure of DV, the case of factors affecting the improvement or change in DV’s, and c) a multiple measure of IV’s and DV’s: the case of latent class of factors affecting the latent class and transition of DV’s. Whereas the first two designs can be analyzed by SEM, LCA, or traditional SEM, last one the specifically requires an innoventive analysis design of LTA-mixIRT or LTA-MRM.