Source discrimination, item detection, and multinomial models of source monitoring

Source monitoring refers to the discrimination of the origin of information. Multinomial models of source monitoring (W. H. Batchelder & D. M. Riefer, 1990) are theories of the decision processes involved in source monitoring that provide separate parameters for source discrimination, item detection, and response biases. Three multinomial models of source monitoring based on different models of decision in a simple detection paradigm (one-high-threshold, low-threshold, and two-high-threshold models) were subjected to empirical tests. With a 3 (distracter similarity) x 3 (source similarity) factorial design, the effect of difficulty of item detection and source discrimination on corresponding model parameters was examined. Only the source-monitoring model that is based on a two-high-threshold model of item recognition provides an accurate analysis of the data. Consequences for the use of multinomial models in the study of source monitoring are discussed.