Complex sentence: The term "hidden variable theory" is used in the interpretation of quantum mechanics, it refers to all types of theory that attempt to account for the probabilistic features of quantum mechanics by the mechanism of underlying inaccessible variables.
Split into simpler sentences: The term "hidden variable theory" is used in the interpretation of quantum mechanics. It refers to all types of the theory that attempt to account for the probabilistic features of quantum mechanics by the mechanism of underlying inaccessible variables.