Since the ability to make correct sensory judgments can vary substantially from person to person, it is important in the training and selection of inspectors to be able to distinguish among inspectors of differing sensory abilities. A probabilistic procedure was recently suggested for classifying inspectors as“qualified”or“unqualified.”Besides assuming that only two classes of inspectors exist, this procedure assumes that all inspectors within a class have the same sensory abilities. The purpose of the present paper is to extend this classification scheme by relaxing both of these assumptions so as to better account for the variation in inspection error between and within inspector classes.