Model specification
For each outcome variable, four two-group models reflecting four alternative hypotheses will be specified and compared. First, Model A will include for both groups a latent intercept but not a latent slope (i.e., a latent change factor), reflecting the hypothesis that scores on the outcome variable will not change from pre- to posttest for either the intervention group or the matched comparison group. Second, Model B will include a latent slope for the intervention group but not for the matched comparison group, reflecting the hypothesis that scores for the intervention group will change, but scores for the matched comparison group will not change. Third, Model C will include a latent slope for the matched comparison group but not for the intervention group, reflecting the hypothesis that scores for the matched comparison group will change, but scores for the intervention group will not change. Fourth, Model D will include latent slopes for both groups, reflecting the hypothesis that scores for both the intervention group and the matched comparison group will change. For each model, outcome variables will be modeled as latent variables with multiple indicators (either items or item parcels) to account for measurement error. Thus, latent intercepts and latent slopes will be second-order factors.