Diverse learners frequently have difficulties applying what they have learned to solve complex problems and determining when and where to utilize strategies they have been taught (Dixon, et al., 1996). Therefore, discernible and distinct strategies should be identified and explicitly taught that enable learners to solve difficult tasks. Conspicuous strategies are an approximation of the steps experts follow covertly (and, perhaps, unconsciously) while working toward similar goals. Good strategy instruction starts with developing a well-organized knowledge base of component concepts and determining how to apply the big ideas of their relationships in observable, definitive steps.
Big ideas in earth science are generally used to make predictions. In the Earth Science videodisk program, strategies for using the big ideas of science are initially made conspicuous for students through the use of visual maps and models which represent expert knowledge and refute common misconceptions. For example, a strategy for using density requires students to identify equivalent volumes in two substances, compare the masses within those volumes, and predict which substance will sink. These steps are not made conspicuous by orally reciting them. They are made conspicuous through "scaffolding."