Background: Very little prospective randomized experimental research exists on the use of simu­lation as a teaching method, and no studies have compared the two strategies of using the HPS? and a CD-ROM. In addition, no researchers have investigated the effects of simulation on various levels of cognition, specifically lower-level and higher-level cognition or critical thinking. Objectives: A prospective pretest-posttest experimental mixed design (within and between) was used to determine if there were statistically significant differences in HPS? and CD-ROM educa­tional strategies in lower-level, higher-level cognition and critical thinking. Results: A repeated measures multivariate analysis of variance (RMANOVA) with LSD post-hoc tests were used to analyze the data. There were no significant differences between the HPS? and CD-ROM groups on lower-level cognition scores. The HPS? group did significantly better than the CD-ROM group on higher-level cognition and critical thinking scores. Conclusion: This study demonstrated that the choice of teaching strategies for lower-level cogni­tion does not make a statistically significant difference in outcome. However, the HPS? is supe­rior to using CD-ROM and should be considered as the choice in teaching. Keywords: simulation, teaching strategies, cognition, critical thinking