With any group assignment, there are a number of decisions that need to be made before introducing the assignment to students. Some of those decisions have to do with features of the assignment (e.g., what will you assess and when will you assess it) and others have to do with features of the group, such as group size, composition, and structure. How groups are assigned is the first element of the collaborative project that students typically encounter, so it seems like a good place to start a discussion of designing high-impact group projects and collaborative assignments.

In a previous post, I mentioned an article by Michael Thom, which took a critical look at the research on group projects. In that article, he states that, “When it comes to membership, allowing students to form groups on their own is superior to other methods of assignment” (p. 7). This is an oddly definitive claim in an article that spends a good deal of time critiquing others for drawing hasty conclusions from research about group projects. His argument in favor of self-selected groups is based on the belief that students in self-selected groups have a more positive subjective experience of the group work, and that they perform better than students in groups that are assigned by an instructor.

Wouldn’t it be nice if this was all that needed to be said? I would love a clear and simple recommendation like this, and to have one that relieves instructors of the mental labor of having to design and implement a strategy for creating student groups would be great. Unfortunately, I don’t think this is the case.

Part of my reluctance to go along with this recommendation has to do with skepticism over some of the research cited in Thom’s article. For example, one study that he uses as evidence that self-selected groups are superior (Bacon et al. 1999) is directly contradicted by another study – which was not referenced – that showed the opposite results despite using a virtually identical design (Fiechtner and Davis 1984). Another article includes recommendations about group structure, but empirical evidence is not provided to support the recommendation (Strong and Anderson 1990). Still another study he cites use students’ self-reported perceptions of their learning as an outcome to measure performance (Myers 2012). It’s somewhat ironic that he includes this because he criticizes using students’ perceptions of their own learning as an outcome measure elsewhere in the article.

Beyond the quality of the methods, there are other issues with the research that make it difficult to interpret the nature of the relationship between method of group assignment and outcomes. When researchers examine decisions related to group assignment, they typically explain the results in terms of group composition, rather than assignment itself. That is, they may make the argument that allowing students to self-select groups leads to more cohesive groups, and group cohesion leads to better outcomes. The problem is that although group composition and group assignment are closely related constructs, they are distinct. Group composition refers to the actual makeup of the group – the different people in it, their different attributes, and the different intragroup relationships, whereas group assignment is simply the method by which people are selected to be in a group. It is possible that the act of assigning groups or allowing students to self-select could have an influence on student outcomes apart from their effect on group composition.

This distinction between group assignment and group composition is more than just a trivial point. There are implications for how we study the construction of effective collaborative learning groups and for how we teach. For example, it could be that group assignment matters beyond the possible impact it has on group composition. Allowing students to select their own groups may make them feel greater autonomy and empowerment at the onset of the project. This could increase group members’ motivation to see the group succeed, since they themselves created the group. Alternatively, assigning students to groups in a transparent and intentional manner could serve as a signal to students that the instructor has been thoughtful and deliberate in designing the project. This could lead students to treat the assignment more seriously and to perceive the instructor as a reliable and willing source of support if help is needed. In either case, method of group assignment is proposed to have non-compositional influences on the group that could affect learning.

Additionally, there are problems when trying to draw summary conclusions from the body of research looking at group assignment practices. Group assignment is often characterized as fitting into one of three broad categories: self-selection, random assignment, and intentional instructor selection, but most studies make comparisons between only two of these methods. For example, a quasi-experimental study cited by Thom compared self-selection to random assignment, and found self-selection to be superior (Chapman et al. 2006). This could be interpreted as evidence that self-selection is the ideal method; however, an earlier study (Muller 1989) found that a method in which the instructor created balanced groups based on students’ initial skill levels also produced better results than random assignment. These studies aren’t contradictory even though one shows instructor selection was superior and the other shows self-selection was superior.  All we can really take from these two studies is that random assignment to groups may not be the best strategy.

Even this distinction of three strategies (i.e., self, instructor, and random) is still an oversimplification because it belies the variety of ways in which intentional instructor selection might be used to affect group composition. Muller (1989) created balanced groups intentionally, but what about other ways in which an instructor might intentionally create groups (e.g., based on common interests or diverse backgrounds)? This potential variability creates a problem when summarizing research because the summary may aggregate across qualitatively different strategies to draw a general conclusion.

The problem becomes particularly apparent, when you consider all the possible bad strategies that exist for grouping people. For example, Thom also references a study that assessed the performance of randomly assigned groups compared to groups that the instructor had created based on the students’ learning styles. The fact that the groups that were assigned based on learning styles performed no differently that the randomly assigned groups doesn’t tell me that instructor selection is a uniformly worse strategy. It just shows that grouping students by learning style is ineffective, which makes sense because learning styles theory is just an intuitively appealing myth that simply will not die, despite the fact that it isn’t actually supported by research (Kirschner 2017Newton 2015Willingham et al. 2015; and even a TED talk in case you don’t want to read, because the persistence of this myth is a pet peeve of mine).

Taken another way, consider if I told you that the 1985 film Clue is the best movie of all time (at the very least, it’s the best film adaptation of a board game I’ve ever seen). As evidence for my claim, I present you with data from 100 people who were asked whether they would like to watch Clue or a 3-hour documentary on sedimentary rock formations, and Clue was clearly the preferred option. As further evidence, I also show that a different set of people preferred to watch Clue, rather than one of the Saw movies. Despite this compounding evidence, I still haven’t shown that Clue is the best movie ever made. I’ve just shown that it’s preferred over a documentary about rocks and a gruesome horror movie. Similarly, if five different studies looking at five different intentional instructor group assignment strategies found that self-selected student groups performed better, this still wouldn’t necessarily mean that self-selection is uniformly superior. It would just mean that it is likely superior to those five particular ways that an instructor could compose a group. We would still need to generalize with caution because maybe those were just five bad strategies.

If you’ve stuck with me this far, thank you. I recognize that not everyone shares my interest in research methods, but I believe it serves two important points. First, if we make a claim that a pedagogy is empirically supported or evidence based, then we need to make sure the evidence is of a good quality. Otherwise, these are just meaningless phrases that we say to make ourselves feel good. Second, human beings are complex, and groups – being that they are dynamic entities made up of multiple human beings – have the potential to be orders of magnitude more complex. We need to be prepared for the possibility that simple and clear recommendations will be few and hard to come by.


  • Bacon, Donald R., Kim A. Stewart, and William S. Silver. 1999. “Lessons from the Best and Worst Student Team Experiences: How a Teacher can Make the Difference.” Journal of Management Education 23(5): 467–488.
  • Chapman, Kenneth J., Matthew Meuter, Dan Toy, and Lauren Wright. 2006. “Can’t We Pick Our Own Groups? The Influence of Group Selection Method on Group Dynamics and Outcomes.” Journal of Management Education 30(4): 557-569. https://doi.org/10.1177%2F1052562905284872
  • Fiechtner, Susan Brown, and Elaine Actis Davis. 1984. “Why Some Groups Fail: A Survey of Students’ Experiences with Learning Groups.” Journal of Management Education (4): 58-73. http://doi.org/10.1177/105256298400900409
  • Kirschner, Paul A. 2017. “Stop Propagating the Learning Styles Myth.” Computers & Education 106: 166-171. http://doi.org/10.1016/j.compedu.2016.12.006
  • Muller, Thomas E. 1989. “Assigning Students to Groups for Class Projects: An Exploratory Test of Two Methods.” Decision Sciences 20(3): 623-634. https://doi.org/10.1111/j.1540-5915.1989.tb01571.x
  • Myers, Scott A. 2012. “Students’ Perceptions of Classroom Group Work as a Function of Group Member Selection.” Communication Teacher 26(1): 50–64. http://doi.org/10.1080/17404622.2011.625368
  • Newton, Philip M. 2015. “The Learning Styles Myth is Thriving in Higher Education.” Frontiers in Psychology 6: 1908. http://doi.org/10.3389/fpsyg.2015.01908
  • Strong, James T., and Rolph E. Anderson. 1990. “Free-Riding in Group Projects: Control Mechanisms and Preliminary Data.” Journal of Marketing Education 12(2): 61–67. https://doi.org/10.1177%2F027347539001200208
  • Thom, Michael. 2020. “Are Group Assignments Effective Pedagogy or a Waste of Time? A Review of the Literature and Implications for Practice.” Teaching Public Administration. Advance online publication. https://doi.org/10.1177/0144739420904396
  • Willingham, Daniel T., Elizabeth M. Hughes, and David G. Dobolyi. 2015. “The Scientific Status of Learning Styles Theories.” Teaching of Psychology 42(3): 266-271. http://doi.org/10.1177/0098628315589505

David Buck, associate professor of psychology, is the 2020-2022 Center for Engaged Learning Scholar. Dr. Buck’s CEL Scholar project focuses on collaborative projects and assignments as a high-impact practice.

How to cite this post:

Buck, David. (2020, September 4). Beware of Simple Universal Recommendations about Group Assignment [Blog Post]. Retrieved from https://www.centerforengagedlearning.org/beware-of-simple-universal-recommendations-about-group-assignment