An earlier review by the author reported an aptitude-treatment interaction (ATI) relating instructional feedback and prior knowledge. For low prior knowledge learners, single-try feedback (STF) was slightly superior to multiple-try feedback (MTF), while for high prior knowledge learners, MTF was superior to STF. In the current report, raw score data from existing studies that examined STF and MTF, but that had not considered the possibility of an ATI, are combined and reanalyzed by ANOVA (ANalysis Of VAriance). This study addresses the following questions: is there an interaction between learner prior knowledge and number of feedback tries provided by computer-based training (CBT) lessons; and, if so, how large is this effect? The results of this analysis are presented along with a tentative explanation of the observed effect. Prescriptive application of the ATI and suggestions for future study are provided. (Author/MES)