However, our schools have typically and traditionally behaved as if the integration of subject matter were not too important or even detrimental to student achievement. The tenacity of the subject matter curriculum, which organizes subject matter into dis- crete disciplines, has been shaken only briefly by experiments like the activity curriculum and the core curriculum. The activity curriculum on the elementary school level and the core curriculum on the secondary school level sought to break down the disciplinary bar- riers and to organize education around problems to be solved, using whatever subject matter was applicable. The popularity of integrated curricula has waxed and waned over the years. We are witnessing a renewed interest in curriculum integration, particularly at the middle school level where interdisciplinary programs are a common feature.