Considerable behavioral evidence has been cited in support ofthe COVIS dual-system model of category learning (Ashby &Valentin, 2016). The validity of the inferences drawn fromthese data critically depend on the accurate identification ofparticipants’ categorization strategies. In the COVIS literature,participants’ strategies are identified using a model-based anal-ysis inspired by General Recognition Theory (Maddox, 1999).Here, we examine the accuracy of this analysis in a model-recovery simulation. We find that participants can appear tobe using implicit, procedural strategies when their responseswere actually generated by explicit rule-based strategies. Theimplications of this for the COVIS literature are discussed.