Six studies discussed in this paper compared error-specific or model-based remediation (MBR) with reteaching in algebra. MBR points out, and highlights as incorrect, errors specific to the student's solution before reteaching the correct procedures. Reteaching shows the student the correct procedure without addressing specific errors. Three of these studies used humans as tutors, and three used an intelligent tutoring system, RPIXIE. The results show that MBR and reteaching are both more effective than no tutoring; however, MBR is not clearly more effective than reteaching. Finally, the results are discussed both in terms of stability of errors, as well as their relevance to both educational practice and the field of intelligent tutoring systems (ITSs). Results suggested that classical computer-assisted instruction for algebra would be as effective as an ITS. (Author/TW)