This study explores the spontaneous explanatory models children construct, critique, and revise in the context of tasks in which children need to predict, observe, and explain phenomena involving magnetism. It further investigates what conceptual resources students use, and in what ways they use them, to construct explanatory models, and the obstacles preventing them from constructing a useful explanatory model. Our findings indicate that several of the children were able to construct explanatory models. However, of the six children interviewed multiple times (three third-graders and three sixth-graders), only one was consistently able to critique and revise her models to arrive at a consistent, coherent, and sophisticated explanatory model. Connecting intuitive knowledge and abstract knowledge was important in her construction of a coherent and sophisticated explanatory model. Students who relied only on intuitive knowledge constructed tentative and non-sophisticated explanatory models. Students who relied only on verbal-symbolic knowledge at an abstract level without connection with their intuition also did not construct coherent and sophisticated models. These results indicate that instruction should help students to become meta-conceptually aware and connect their verbal-symbolic knowledge and intuition in order to construct explanatory models to make sense of abstract scientific knowledge. (Contains 1 table and 3 figures.)