This is an elementary lecture for students which discusses quantum measurement from the modern perspective of decoherence.
Decoherence and Quantum Measurement: The Missing Lecture
We give an elementary account of quantum measurement and related topics from the modern perspective of decoherence. The discussion should be comprehensible to students who have completed a basic course in quantum mechanics with exposure to concepts such as Hilbert space, density matrices, and von Neumann projection (``wavefunction collapse'').See also:
Macroscopic Superpositions in Isolated Systems (talk video + slides)