The 2006 round of the Program of International Student Assessment (PISA), run by the Organisation for Economic Cooperation and Development (OECD), included 57 countries - nearly 90 per cent of the world's economy. How has PISA managed to gain such reach? How has it made itself relevant to such a large and diverse set of nations? The growing popularity of large-scale testing is but one example of the global spread of policy ideas. How do policy ideas become global phenomena? Finding theories of diffusion and globalisation inadequate in explaining the large-scale spread of policy ideas, I argue that the notion of assemblage offered by the process sociology of actor-network theory (ANT) provides a useful analytic. Rather than using big ideas to explain how certain situations have come to be, ANT uses situations to explain how certain ideas have become big. It offers a way to understand even apparently established networks as fluid assemblages that are continually built and translated, and provides the tools for thinking differently, and with greater agency, about issues that appear powerful and entrenched. It has been argued that deconstruction, which has been the main approach of policy researchers in recent years, is no longer adequate, and that new theories to understand and to engage with policy-making are urgently needed (Gale, 2006). ANT offers the role of 'assembler' rather than 'deconstructionist' to the policy researcher, and thus has the potential to transform policy analysis. To view policy phenomena using this analytic is to bypass tired debates and adversarial stories of power struggles, and to create spaces of hope and negotiation.