 More traditional approaches to quantum mechanics that somehow privilege the notion of measurement or observation also may have less-than-obvious connections with decoherence and in fact fit less well with it, but we shall look at von Neumann’s, Heisenberg’s and Bohr’s views. Finally, we shall briefly mention other approaches and remark on their various relations to decoherence. These will be Nelson’s stochastic mechanics, modal interpretations, and QBism. 