  Decoherence is widely felt to have something to do with the quantum
measurement problem, but getting clear on just what is made difficult by the
fact that the "measurement problem", as traditionally presented in foundational
and philosophical discussions, has become somewhat disconnected from the
conceptual problems posed by real physics. This, in turn, is because quantum
mechanics as discussed in textbooks and in foundational discussions has become
somewhat removed from scientific practice, especially where the analysis of
measurement is concerned.
  This paper has two goals: firstly (sections 1-2), to present an account of
how quantum measurements are actually dealt with in modern physics (hint: it
doesn't involve a collapse of the wavefunction) and to state the measurement
problem from the perspective of that account; and secondly (sections 3-4), to
clarify what role decoherence plays in modern measurement theory and what
effect it has on the various strategies that have been proposed to solve the
measurement problem.
