The authors compared the exemplar-based random walk model (EBRW) of Nosofsky and Palmeri (1995) and the decision-bound model of Ashby and Maddox (1994; Maddox & Ashby, 1996) on their ability to predict performance in Garner's (1974) speeded classification tasks. A key question was the extent to which the models could predict facilitation in the correlated task, and interference in the filtering task, in situations involving integral-dimension stimuli To obtain rigorous constraints for model evaluation, the goal was to use the models to fit the detailed structure of the response-time distribution data associated with each individual stimulus in each task. Both models yielded reasonably good global quantitative fits to the response-time distribution and accuracy data. However, the decision-bound model failed to adequately characterize the interference effects in the filtering task, whereas the exemplar- retrieval model underpredicted the magnitude of the facilitation effect in the correlated task. Directions for future research and model development were outlined.