Sequences of statistical experiments over micro-objects

The presence of two principally different methods of arranging sequences of statistical experiments over micro-objects is ascertained. The first of them consists in distinguishing at each moment of the measurements its statistical collective, so that each replica of it undergoes one interaction with the instrument. The second assumes the participation of one collective in several sequential experiments. It is noted that the mathematical formalism of quantum mechanics directly reflects the statistical structure arising only in the first of the mentioned ways.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 66–71, January, 1990.