This paper examines collaborative researcher-practitioner knowledge work around assessment data in culturally diverse, low socio-economic school communities in Queensland, Australia. Specifically, the paper draws on interview accounts about the work of a cohort of school-based researchers who acted as mediators bridging knowledge flows between a local university and a cluster of schools. We draw on the concept of recontextualisation to explore the processes of knowledge mediation in dialogues around student assessment data to design instructional innovations. We argue that critical policy studies need to explore the complex ways in which neoliberal education policies are enacted in local sites. Moreover, we suggest that an analysis of collaborative knowledge work designed to improve student learning outcomes in low socio-economic school communities necessitates attention to the principles regulating knowledge flows across boundaries. In addition, it necessitates attention to the ways in which mediators navigate dilemmatic spaces, anxieties and affects/feelings in order to generate innovative learning designs in the current global context of high-stakes national testing and accountability regimes.