Integrative curriculum design promises much for middle level teachers who wish to develop classroom programmes that will encourage early adolescents to actively engage in their learning (Beane 1990, 1997). Beane's model is highly responsive to the educational and developmental needs of young people. In contrast, multidisciplinary curriculum design (Jacobs 1989) may result in significant but largely unrecognised drawbacks when it is implemented in the middle grades. This paper critically examines the theory of the integrative and the multidisciplinary models of curriculum integration with respect to middle level curriculum reform in Australian schools. It draws its data from a doctoral study (Dowden 2007) that traced a century of development of curriculum integration in the USA: from Dewey's Laboratory School a century ago through to contemporary middle schooling.