The poor success rate of policy for curriculum change has been widely noted in the educational change literature. Part of the problem lies in the complexity of schools, as policy-makers have proven unable to micro-manage the multifarious range of factors that impact upon the implementation of policy. This article draws upon empirical data from a local authority-led initiative to implement Scotland's new National Curriculum. It offers a set of conceptual tools derived from critical realism (particularly the work of Margaret Archer), which offer significant potential in allowing us to develop greater understanding of the complexities of educational change. Archer's social theory developed as a means of explaining change and continuity in social settings. As schools and other educational institutions are complex social organisations, critical realism offers us methodological tools for tracking the ebbs and flows of change cycles over time, presenting the means for mapping the multifarious networks and assemblages that form their basis. (Contains 2 figures and 3 notes.)