This chapter discusses pivotal cases, a class of scientific examples that when added to the mix of ideas used by the students to make sense of complex scientific situations, promote knowledge integration. It describes research on pivotal cases to help curriculum designers, including teachers, create pivotal cases for new topics. The chapter analyzes the spontaneous cases generated by two students to make sense of insulation and conduction during their eighth-grade science course and report on how these cases contribute to the understanding of high school science. It describes compelling comparisons between traditional instruction and instruction with pivotal cases and characterize how pivotal cases might improve student learning. Finally It identifies features of pivotal cases and discuss how pivotal cases can help achieve the goals of science courses. The deliberate nature of the learner refers to the decisions individuals make about selecting science experiences and persisting in scientific problem solving.