Student Learning Outcomes and Attitudes Using Three Methods of Group Formation in a Nonmajors Biology Class

Abstract

Group work is often a key component of student-centered pedagogies, but there is conflicting evidence about what types of groups provide the most benefit for undergraduate students. We investigated student learning outcomes and attitudes toward working in groups when students were assigned to groups using different methods in a large-enrollment, student-centered class. We were particularly interested in how students entering the class with different levels of competence in biology performed in homogeneous or heterogeneous groups, and what types of group compositions were formed using different methods of group formation. We found that low-competence students had higher learning outcomes when they were in heterogeneous groups, while mid- and high-competence students performed equally well in both group types. Students of all competence types had better attitudes toward group work in heterogeneous groups. The use of student demographic variables to preemptively form groups and allowing students to self-select their group mates both yielded heterogeneous competence groups. Students in the instructor-formed, demographic groups had higher learning outcomes compared with students allowed to self-select. Thus, heterogeneous groupings provided the most benefit for students in our nonmajors, large-enrollment class.

FIGURE 1.

Structure of the three classes in this study, including types of assessments and how they were administered.

FIGURE 2.

Individual postassessement scores by preassessment performance and group type, with lines indicating model estimates from the MLM for each student group. Low-competence (LPS) students in heterogeneous groups performed better on average compared with LPS students in homogeneous groups, as indicated by the separation between model estimates for homogeneous groups and heterogeneous groups for students with lower preassessment scores. The difference in postassessment scores by group type for mid-competence (MPS) and high-competence (HPS) students is in the opposite direction, but is much smaller. This analysis supports hypothesis 1.

FIGURE 3.

Change in the four SAGE factors of low- , mid-, and high-competence (LPS, MPS, and HPS, respectively) students in heterogeneous and homogeneous groups. Error bars represent SE. Change in quality of product and frustration (satisfaction) was significantly greater for students in heterogeneous groups compared with students in homogeneous groups. This analysis supports hypothesis 2.

FIGURE 4.

Observed group types realized when students were allowed to self-select their groups compared with group types predicted by random assortment, which was determined by 1000 simulations. Error bars for the simulated groups, representing SD, are present but very small. This analysis supports hypothesis 4.