The case for coherence in scientific explanations: quantitative details can hurt qualitative understanding

In Experiments 1A and 1B, students read a concise booklet containing 653 words and 6 illustrations describing the formation, propagation, and dispersion of ocean waves (concise group) or an expanded booklet containing 327 additional words and 5 additional illustrations describing relevant mathematical formulas and computations interspersed throughout the lesson (expanded group). In Experiment 2, students viewed a multimedia presentation of narrated animations based on the concise or expanded booklet. In both studies, the expanded group performed more poorly than did the concise group on problem-solving transfer tests. The added quantitative details may have distracted the learner from constructing a qualitative model of the process of ocean waves.