This paper describes, in the context of one highly circumscribed element of English educational policy, namely, "Threshold assessment," the ways in which the boundaries between the public and the private have become increasingly porous and blurred. In this context, some consequences and implications of private sector involvement in public education are explored. Points of articulation between the specific issues we have encountered in our recent research project "The impact of performance threshold assessment on teachers' work" (ESRC R000239286), and more general debates about public/private policy relationships, are discussed. The paper concludes with some general observations about the nature of those debates and the issues we have encountered. (Contains 3 notes.)