We found when students assume the role of peer educator they prepare more for small group sessions, with the magnitude of change being greatest for those students who normally prepare least. We also found a small, but significant, improvement in knowledge acquisition and retention for clinical presentations where students had been peer educators compared to those for which they were simply a member of the group.
These findings lend support to the notion that medical student preparation for small group sessions improves learning. Several authors have advocated for PAL as a way to prepare medical students for their future role as educators. [17
] PAL has been encouraged as a way to improve student communication skills, enhance motivation to learn, provide role models for junior students, and reduce faculty teaching burden.[17
] The results of our study reinforce the importance of including improved learning on that long list of benefits.
Our results are consistent with those of other studies in the psychology and medical education literature that also found a learning benefit associated with involvement in teaching. [9
] But compared to previous studies involving medical students, our study methodology was different. By virtue of its cross over design, so that each student served as their own control, as well as the random allocation of the intervention (involvement in teaching) and the lack of additional training we avoided the potential confounders of selection bias and performance bias of these previous studies.[10
While it may seem intuitive that involvement in teaching should improve learning, this may not always be the case.[9
] When a novice learner is presented with complex material a large intrinsic cognitive load is placed on working memory.[20
] Performing tasks not directly related to learning – such as preparing for teaching – may generate an extrinsic cognitive load that may inhibit learning. Fortunately, we did not observe these potentially negative consequences of PAL – suggesting that this is a 'win-win' strategy.
In addition to increasing preparation time there are several explanations as to why involvement in teaching may improve the quality of learning. The first is that it motivates the learner to spend more time preparing, thereby possibly resulting in deeper learning. Teaching in the classroom also requires that concepts be verbally explained to the learner; this process of vocalization has been demonstrated to be an effective independent cognitive strategy for learning.[21
] In addition, students may not be able to accurately assess their own knowledge deficiencies. By interacting with their peers in a classroom setting and attempting to answer questions from the group, peer educators may gain insight into which concepts they have a thorough understanding of and for which they need to study further. Finally, making participation in PAL an expectation may be enough to stimulate extrinsically motivated students to learn, while intrinsically motivated students may be rewarded by a sense of competence, autonomy, and relatedness by leading a small group discussion.[22
] Although we did not evaluate this directly, irrespective of how much students typically prepared for small groups, we found that preparation time increased when they assumed the role of peer educator. Unfortunately, we were unable to assess whether the amount of time students spent preparing could be used to predict scores on the MCQ exam due to the anonymous nature of our survey, but should be explored further.
Importantly, our study design only allowed us to conclude students benefited from becoming involved in the entire process of teaching. Not only does this process include the time spent in the classroom actively teaching, but also includes the time spent preparing for the session and reflecting upon it after it has occurred. Determining to what extent each of these aspects contributed to the students' knowledge gains remains unknown. So while the act of teaching in the classroom may improve learning, the role that the significant amount of additional time students spent preparing for the session in our study cannot be ignored and should be explored in future studies.
There are several limitations to our study. Firstly, our results, while statistically significant, show a relatively small absolute difference in examination scores when a student was the peer educator compared to when they were participating as a group member. This may reflect that students still prepared for the sessions even when they were not peer educators or that the time between the small group sessions and the end of course examination was between one and 12 weeks – so our study evaluated the effects of involvement in teaching on knowledge retention rather than simply short-term knowledge acquisition. It should be noted that our effect size for knowledge gains is very similar to other studies in the literature that evaluated the effect of peer educators in courses of similar length.[9
] Secondly, we conducted our study using a single course in a single medical school with a clinical presentation curriculum, so our results may not be generalizable. Finally, our use of student self-reported preparation times introduces the possibility of recall bias. Further studies are clearly needed to confirm, and explain, the performance benefits associated with involvement in teaching.