The study by Walker et al (2017) is from Kentucky. I like that this study does not spend time on establishing whether or not cooperative learning works but simply cites the existing evidence. Instead, this study is focusing solely on the impact of stable vs shifting teams on the efficacy of cooperative learning. Their results suggest that stable teams are more effective in producing better learning outcomes. The student population being studied was a freshman undergraduate sociology course. What is interesting is that it is not only the stability of the team that produces improved student learning outcomes but also the time on task similar to what the study from Mazur found below to explain why females had greater gains than males. In the Walker et al (2017) study, there were no differences in the first term comparing stable vs shifting teams. There was, however, a significant difference in the second semester when time spent discussing material in teams was increased (the amount of time viewing a film was reduced). Note that although this study involved large enrollment classes (150-175 students) the study was conducted in the tutorials (recitation sessions) that were smaller subsets of the class lead by teaching assistants (TA) rather than faculty. Also, note that the one TA choose to shift teams due to pedagogical beliefs that all students deserved to have a chance to work in a high-functioning team. In contrast, the other TA created stable teams based on their reading of the TBL literature which suggests that stability develops stronger relationships which enhance the learning environment. I have some issues with the introduction in the Walker et al paper (2017): they make many blanket statements about the typical university student experience (large classes, relatively unengaged) without citing any evidence that this is in fact, the case. I am sure it is the case, but in a peer-reviewed publication, I expect the evidence to be cited that this is true.
Mazur's paper studied the effect of peer instruction (PI) on science students' beliefs in physics and towards learning physics. The effects of a stable team environment in the PI groups was also investigated. Students' attitudes were measured using the Colorado Learning Attitudes Toward Science Survey. The students were at a university in China. The results indicate that PI improved students' attitudes and that this increase was greater when the PI teams were stable throughout the term. It seems to me that the study was undertaken in order to determine why many studies indicate that students' attitudes toward physics in undergraduate physics courses deteriorate becoming more novice like. This is similar to what I have seen in my 1st-year biology course with the Learning Environment Preferences survey (paper in preparation) when students are not assigned the task of developing their learning philosophy. I found Mazur's results interesting because, in both of my courses, PI instruction was occurring in the form of TBL. In the class in which a learning philosophy was not assigned students' cognitive complexity index decreased (becoming more novice like). Zhang et al (2017) also determined a gender effect in which females seemed to make greater gains than males in the PI courses. Further study suggested that this may be a result of females discussing to a greater extent during team discussions of the in-class questions set by the instructor. The only criticism of the study that I have is that in the variable team PI group, the researchers are assuming that the students formed teams randomly during each class. However, it is possible that students may sit in the same place in class from day to day and sit with their friends. Thus, although team stability was not enforced, neither was team variability.
Regardless, these are interesting results and provide evidence for what many TBL practitioners have observed in their courses: Over time, stable learning teams become more effective at learning.
Michaelsen, L. K., Watson, W. E., & Black, R. H. (1989). A realistic test of individual versus group consensus decision making. Journal of Applied Psychology, 74(5), 834–839.
Sibley J. 2016. Using Teams Properly. LearnTBL.
Walker, A., Bush, A., Sanchagrin, K., & Holland, J. (2017). “We’ve Got to Keep Meeting Like This”: A Pilot Study Comparing Academic Performance in Shifting-Membership Cooperative Groups Versus Stable-Membership Cooperative Groups in an Introductory-Level Lab. College Teaching, 65(1), 9–16.
Zhang, P., Ding, L., & Mazur, E. (2017). Peer Instruction in introductory physics: A method to bring about positive changes in students’ attitudes and beliefs. Physical Review Physics Education Research, 113(1), 10104.