2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/89103Maximum-likelihood estimation is applied to identification of an unknown quantum mechanical process represented by a ``black box''. In contrast to linear reconstruction schemes the proposed approach always yields physically sensible results. Its feasibility is demonstrated using the Monte Carlo simulations for the two-level system (single qubit).REVTeX, 4 pagesQuantum Physicstext