2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143371This is a preliminary version of an article to appear in the forthcoming Ashgate Companion to the New Philosophy of Physics. I don't advocate any particular approach to the measurement problem (not here, at any rate!) but I do focus on the importance of decoherence theory to modern attempts to solve the measurement problem, and I am fairly sharply critical of some aspects of the "traditional" formulation.LaTeX, 85 pages. Forthcoming in Rickles (ed.), The Ashgate Companion to the New Philosophy of PhysicsQuantum Physicstext