To investigate whether the impact of ADHD and class context on on-task behavior is related to levels of teacher supervision, the two main sets of analyses were repeated with additional inclusion of teacher supervision as a covariate. To better understand this relation, we explored (a) the impact of ADHD and class context on teacher supervision by repeating the main analyses with teacher supervision as the dependent variable and (b) the effect of teacher supervision and ADHD on on-task behavior by doing analyses with on-task variables as the dependent variables and group, teacher supervision, and the interaction term as the predictors. All analyses were performed in SPSS (version 19). An alpha of .05 was used for all tests of significance.