The learning cycle is a method of teaching—it is also a curriculum organization principle and is derived directly from the mental functioning model invented by Piaget. Although Jean Piaget contributed to the formation of the learning cycle (Piaget, 1973), its present structure has to be attributed to Dr. Robert Karplus and the persons who developed the materials of the Science Curriculum Improvement Study (SCIS). It was through the SCIS activities that many of us learned how to develop curricula and teach with the learning cycle. The learning cycle is built upon the premise that three distinct phases are necessary in developing understanding of a concept, that those phases have a definite sequence, and each phase has a definite structure or form. The research done in testing the form variable has already been reported in this journal (Renner, Abraham, & Birnie, 1985). This report explores whether or not each learning-cycle phase is necessary in learning a concept.