In this essay, Robert Floden reviews three recent volumes in the Philosophy, Theory, and Educational Research series that address the philosophical implications of three "isms"-- postpositivism, pragmatism, and poststructuralism--for empirical educational research. These volumes, written by D.C. Phillips, Gert J.J. Biesta, and Michael A. Peters, each in partnership with Nicholas C. Burbules, draw on several lines of currently active philosophical work to address a challenge to educational researchers: What can empirical research hope to accomplish, given the evident difficulties in discovering any tight connection between, on the one hand, instructional methods and policy directives and, on the other hand, student outcomes, especially student learning? The traditions discussed are rough groupings of scholars, with views that are loosely overlapping, rather than clearly defined. Floden observes that the general ideas represented in postpositivism and pragmatism offer researchers frameworks that support optimism about the contributions of empirical work. In contrast, the book on poststructuralism illustrates scholarship in that tradition, but suggests that most research reports will be colored by power relations and be open to multiple interpretations. Floden concludes that empirical researchers may find material in these books enlightening, but will probably need assistance from philosopher colleagues to see how they can inform the practical work of empirical research.