Bousfield classes over a p-group Mark Hovey, Department of Mathematics, Wesleyan University, Middletown, CT 06459, John H. Palmieri, Department of Mathematics, University of Notre Dame, Notre Dame, IN 46556, Abstract: Extending work of Benson, Carlson, and Rickard on thick subcategories of finitely generated modules over a p-group, we completely describe the partially ordered set of Bousfield classes of all modules over a p-group: it is isomorphic to the poset of subsets of the prime ideal spectrum of the group cohomology algebra. This is a preprint.