How do teachers use curriculum knowledge when implementing an innovative curriculum model? In what ways does their knowledge assist them? How can we assess their understanding? What factors support or impede teachers' use of curriculum knowledge in school improvement? This study sought to assess how teachers used their knowledge of curriculum during the implementation of a nontraditional model of curriculum approach. Curriculum knowledge was broadly defined as the ability to apply theoretical principles and behaviors associated with planning, implementing, and evaluating the curriculum (Behar, 1994), in differentiating instruction (Joyce, Weil, & Showers, 1993), and in enhancing the capacity for responsiveness to the social context and dynamics of the student classroom milieu.