Most importantly, however, we found a differential influence of context on children with ADHD,which could not be explained by the presence of comorbid ODD problems or academic under performance. Although children with ADHD overall showed less time on-task as compared to controls, this effect was due to group differences during individual work and whole class group teaching but not during small group work. Although small group work yielded the highest levels of on-task focus in all children, it seems that children with ADHD benefit especially from this specific class group structure even where no additional supervision is given. During small group work, cooperative learning by interaction with peers is considered to be greater than in other settings. Although each of the group structures considered potentially plays a vital role in the learning process (Baker et al., 2008), the amount of small group work is limited during the observation period. One implication of the current studywould be the promotion of this sort of class setting for ADHD pupils. Academic content was also important in this regard. Even after controlling for academic performance, shorter on-task span in children with ADHD as compared to controls was present during mathematics and language, during sciences, and during instructional transition periods, but not during music and arts. Rapport et al. (2009) suggested that, compared to laboratory tasks, classroom academic tasks typically involve more controlled processing, place greater demands on cognitive resources, including the ability to store and manipulate information in working memory, and require complex strategic mechanisms of self-regulation and planning which can adapt flexibly to changes in the classroom environment. As on-task behavior can be seen by the product of child by environment, this result may reflect the outcome of a unique combination of high educational demands of the environment and typical deficits associated with ADHD to cope with these demands.