Over the past several decades, empirical support for inquiry-based forms of science teaching has accumulated. Critical voices, however, also exist, claiming that minimally guided teaching approaches might be less effective than guided forms; they might even be harmful, particularly for novice students, due to the production of cognitive overload.…

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…