INDIVIDUAL ASPECTS OF QUANTUM MEASUREMENTS

The following two claims have been put forward in support of an indivi dual interpretation of quantum mechanics: within the framework of quan tum measurement theory, (i) the concept of measurement of a sharp obse rvable can be completely characterized in terms of the notion of calib ration, and (ii) the frequency interpretation of probability (of a mea surement outcome) can be founded on the notion of a property of an ind ividual system. Here we set out to generalize these results to measure ment schemes which may be unitary or non-unitary and to object and poi nter observables which may be sharp or unsharp.