This study focuses on the impact of team formation approach on teamwork effectiveness and performance spanning three years of instruction of the chemical engineering unit operations laboratory, which is an upper-level undergraduate laboratory course. Team formation approaches changed each year, and assessment tools, including peer-assessment, academic performance, and course evaluations, were employed to evaluate team performance. Approaches included three cases: instructor-selected teams based on GPA with the objective of a similar cumulative average GPA for each team, student self-selected teams, and a combination of self-selected teams with instructor-selected teams for a final experiment. For the third case, new teams were assigned based on a common interest to learn about a specific final laboratory experiment or research topic, and the instructor identification of both low- and high-performing students in the prior teams. Team effectiveness and performance were assessed using CATME, a teamwork VALUE rubric developed by the Association of American Colleges and Universities (AAC&U), and numerical peer-contribution forms. In addition, assigned team leaders for each experiment provided feedback regarding individual team member performance, including contributions to reports and presentations. Results demonstrated that less than five percent of the students presented team conflicts when students self-selected teams for the laboratory course; however, strong or weak teams were formed leading to unbalanced laboratory performance. On the contrary, course evaluation outcomes were improved when students were assigned to teams based on cumulative GPA or reassigned by the instructor for the completion of a final experiment. Overall, this study demonstrates that a combination of student-selected and instructor-selected teams during the same semester led to better course outcomes and enhanced individual experiences, as shown by the students’ evaluations of the laboratory course
