Despite considerable achievement in inclusive research, people with intellectual disabilities have been largely excluded from the critical area of data analysis and theory development. Next to the undoubted complexity of these tasks, this can partly be attributed to higher demands of representativeness that are used to judge the validity of…

Background: Securing appropriate challenge or preventing boredom is one of the reasons frequently used to justify ability grouping of gifted students, which has been shown to have beneficial effects for achievement. On the other hand, critics stress psychosocial costs, such as detrimental effects on academic self-concept (contrast or…