Expert competence5,12 is a primary goal of education and is another area in which research has provided useful insights. Expert competence has been found to have roughly two parts: factual knowledge and an organiza- tional structure that allows the expert to effectively re- trieve and apply those facts. Organizing physics ideas around general concepts is part of building such a struc- ture. If students do not have a suitable organizational structure, simply pouring additional facts on them may ac- tually deter learning.