Outcome measures will be evaluated in separate analyses. Data from primary outcomes will be evaluated using mixed-effects analyses '(SAS, PROC MIXED),' which allows for incomplete data and covariance structures other than compound symmetry. In addition to the study condition indicator, these models will include, in the fixed effects portion of the model, a main effect for time as well as a two-way interaction between study condition and time. The key estimate from this model is the two-way interaction effect, which indicates whether changes in outcome (e.g., knowledge) over time are different for the two conditions.