Key points are not available for this paper at this time.
Two procedures are developed for classifying an individual system as |p> or |q>, non-orthogonal, given an ensemble with respective proportions r and 1—r. One (generalizing Ivanovic, Dieks, and Peres) infallibly classifies some systems, leaving others unclassified. The second is statistically optimum, allowing individual errors.
Jaeger et al. (Sun,) studied this question.