1. A method for evaluating media-playing sets, each set being characterized by a plurality of input parameters having respective values, said method comprising: (a) collecting data identifying for each member of a sample group of said sets whether a selected performance condition has occurred; (b) analyzing said data so as to relate said selected performance condition to characteristic ones of said input parameters and, also, to prescribed values of said characteristic ones of said input parameters; and (c) evaluating the likelihood of said selected performance condition occurring in a subject set by detecting the respective values of at least those ones of said input parameters of said subject set corresponding to said characteristic ones and comparing said respective values to said prescribed values.