The evaluation model for mastery testing as proposed by Emrick (1971) represents an empirical approach to determining the most appropriate mastery criterion score that should be established in those testing situations which entail decision making relative to the continued progression or possible recycling of students in a given learning sequence. It is suggested in Emrick's model that practitioners and researchers alike are no longer limited to intuitive appeal or field-related precedents as a basis for establishing appropriate mastery score standards. Though not explicitly stated by Emrick, his model can be algebraically rewritten and its facility logically extended to accommodate those situations in which an ex post facto investigation is desired so as to determine the relative cost of decision errors associated with a previously administered mastery test which specified a given criterion score. (Author)