In Chapter 1, we defined the learning that we want to help students accomplish as the iterative process of building, testing, and refining mental models. The goal that most instructors would set for this learning is to help students “understand” science. This means that we want students to go beyond merely memorizing science “facts” and be able to use the knowledge that they have acquired to solve science-related problems. In other words, students should be able to “use” the knowledge they have gained in novel situations, ones that they have not previously encountered. This, of course, requires students to “know” many “facts,” be able to organize those facts into concepts, relate these concepts to other facts and concepts, and know which concepts are relevant to use in dealing with a new situation.