Collaborators

Gina Frey (Executive Director The Teaching Center and Chemistry)
Susan Hockings (Chemistry)
Karen DeAngelis (Cornerstone)

Purpose and Rationale

This project evaluated the effectiveness of Washington University’s implementation of Peer-Led Team Learning (PLTL) in General Chemistry.

Many studies have shown that active and collaborative learning can improve student learning. One model of active and collaborative learning is Peer-Led Team Learning (PLTL), which has been used extensively to supplement large lecture courses, typically in science and mathematics. In PLTL, 6-8 students work together to solve problems in a study group facilitated by a Peer Leader who is an upper-level undergraduate student. The course instructor designs the problems and supervises the Peer Leaders.

The PLTL program at Washington University began in General Chemistry and has since been expanded to Calculus. The structure of PLTL at Washington University differs from that of the national model, on which it is based, in one crucial aspect: participation in the PLTL groups is optional, rather than mandatory, for students in each “parent” course. In other words, students self-select into the PLTL groups. However, once students elect to participate in PLTL, their attendance at PLTL meetings is mandatory. This structure was designed to suit a large university setting in which 1) there are multiple sections of the “parent” course, and 2) graduate-student course assistants teach mandatory recitation sub-sections. This setting differs from the setting of the colleges and universities where PLTL was originally developed and shown to be effective.

Objectives

• To determine if participation in PLTL improves student learning and satisfaction in General Chemistry at Washington University
• To investigate the effectiveness of PLTL at a large, highly selective university

Methods

The performance of PLTL participants in General Chemistry in fall 2002 and fall 2003 was compared to the performance of non-PLTL participants in General Chemistry in the same semesters. In addition, an attitudinal survey was administered to the PLTL participants to measure their responses to PLTL and their perceptions of whether PLTL improved their learning and interest in chemistry.

Conclusions

This study found that students who participated in PLTL groups performed about one-third of a grade point (an average of B versus B‒) higher in the first-se¬mester General Chemistry course than students who opted not to participate. This improvement in performance was shown even after controlling for differences in the students’ background characteristics. These results correspond very closely to those found in evaluations of PLTL programs elsewhere. Therefore, the students’ self-selection into the PLTL program at Washington University does not appear to affect the impact of the PLTL model on student learning. This study also found that PLTL participants had positive attitudes toward PLTL as a vehicle for learning and toward the study of chemistry more generally.

This study demonstrates the effectiveness of the PLTL model at a large university and suggests that the PLTL model may be adapted to suit universities in which class-size and course structure differ significantly from the setting in which the model was originally developed and evaluated.
Note: Preliminary analysis of student performance in Calculus among PLTL participants and non-PLTL participants at Washington University has produced similar results.

Papers

Hockings, S. C., DeAngelis, K. J., & Frey, R. F. (2008). “Peer-led team learning in general chemistry: Implementation and evaluation.” Journal of Chemical Education, 85 (7), 990-996.

Weimer, M. (2009) “Peer-Led Team Learning.” The Teaching Professor. http://www.teachingprofessor.com/articles/teaching-and-learning/peer-led….

Workshops and Presentations

Frey, R.F. (2011, October) “Workshop on Peer-Led Team Learning” (and moderator of the Chemical Education Session); “Incorporating Peer-Led Team Learning (PLTL) into Lower Level Chemistry Courses: Implementation and Insights” Workshops at the American Chemical Society Midwest-Great Lakes Regional Meeting.

Hockings, S.C.; DeAngelis, K. J.; Brown, P. L.; Sawyer, K.; & Frey, R. F. (2008, August) “Peer-led Team Learning in General Chemistry.” Poster presented at the 2008 CCLI PI Conference, Washington, DC.