Despite the potential advantages of instructional explanations, evidence indicates that they are usually ineffective. Subsequent work has shown that in order to make instructional explanations effective indeed, one successful strategy is to combine them with indications of the limitations in learners' understanding that they are intended to…

Effective instructional explanations help the students to construct coherent mental representations. To do so, one condition is that they must be tailored to students' needs. It is hypothesized that explanations are more helpful if they also explicitly aid the students to detect problems in their mental representations, as this provokes an impasse…