Classroom inattentiveness is an important reason for clinical referral of childrenwith ADHD and a strong predictor of their educational achievement. This study investigates classroom on-task behavior of Flemish childrenwith ADHDwithdrawn frommedication as a function of instructional context. Thirty-one pairs of children (one with ADHD and one age- and sex-matched control; 25 boys and 6 girls 6 to 12 years of age) were observed in their classroom environment during two
consecutive school days. On-task behavior (time on-task and on-task span) of ADHD and non-ADHD individualswas compared in different class contexts (i.e., different class structures and academic content types). Individualized teacher supervision was simultaneously assessed. Generalized estimation equation analyses showed that children with ADHD were significantly less on-task than controls during individual work and whole class group teaching, but not during small groupwork, and had significantly shorter on-task span during academic tasks (mathematics, language, and sciences) and instructional transitions between tasks, but not during music and arts. These effects persisted even after controlling for the higher levels of teacher supervision observed for ADHD pupils (7%) across all contexts (vs. 4% in controls). Findings suggest that despite receiving more overall teacher supervision, children with ADHD displayed lower levels of on-task
behavior in settings that place high self-regulatory, information processing, and motivational demands on them. This finding may have initial implications for classroom interventions in this population.