Although no single lesson-planning approach will work every time for every student in every situation, researchers continue to conclude that one particular approach outperforms any other when it comes to effectively teaching scientific concepts. This particular method of instruction is called the learning cycle.. The first full introduction of the learning cycle occurred in the 1960s (Karplus and Their 1967 for SCIS, the Science Curriculum Improvement Study) and consisted of three specific phases Exploration, Concept development, and Application. This chapter focuses on each phase of the original learning cycle and includes descriptions of purpose and implementation, alongside a rationale for why the phases are sequenced as they are.