Comparing problem-based learning and lectures.

Abstract

This study documents medical students' opinions of the relative efficacy of PBL versus lectures. Second-year medical students exposed to both traditional lectures and PBL were surveyed regarding their attitudes towards PBL and its effectiveness compared to lectures. Eight-two students" (85%o) completed the anonymous questionnaire. Most students valued PBL. Students favored lectures for efficiency and directing learning, while PBL was endorsed for breadth of learning and enhancing interpersonal skills. Students more often endorsed PBL over lectures in achieving various educational goals.

Introduction

Problem-based learning (PBL) curricula require students and faculty to acquire and refine different skills than a traditional, lecture-based curriculum demand. Though PBL curricular components are widespread (1) in medical education, few schools use it for more than 50% of their preclinical curriculum. Some schools employ it as "tracks" selected by a subset of students rather than required of all. Some studies indicate that while student outcomes do not differ significantly between standard lecture-based curricula and problem-based learning, the latter is harder to implement (2), and poor implementation leads to problems for faculty, and more importantly, participating students. (3). Evidence exists that problem-based learning curricula yield learners with increased competence in teamwork skills, communication skills, independent study abilities (4) and increased lifelong learning skills (5). This approach demands that learners demonstrate flexibility, "generosity with knowledge", and situational awareness. Some programs screen students for qualities that predict success in this instructional format (6), though it might be argued that those with lesser skills for collaborative learning and teamwork need a PBL curriculum the most.

At Michigan State University College of Human Medicine, all of our students participate in a traditional lecture-based curriculum during their first year of medical school, followed by a primarily-problem-based learning curriculum in their second year. While some students support problem-based learning as an effective model of clinical problem-solving, others see the experience as inefficient and highly variable. Faculty support PBL as fostering independent learning but have concerns about the resources required. After experiencing both types of learning, we queried the second year class regarding their attitudes toward PBL as a learning modality. We were interested in two main questions: (1) Did students have a favorable attitude towards problem-based learning? and (2) Did students see problem-based learning as an effective instructional method for achieving various educational goals?

Methods

Study Participants. Ninety-six second-year medical students were asked to complete a brief anonymous questionnaire regarding their attitudes about problem-based learning (PBL) as an educational strategy. The questionnaire was administered to all students in their PBL groups in November 2002 and required approximately 5 minutes to complete. The same questionnaire was administered to students again during their second semester of PBL (March 2003) to determine if further experience with PBL-based learning had an impact on their attitudes. This study was approved by the MSU Committee on Research Involving Human Subjects.

Questionnaire. The first part of the survey included 11 statements about PBL derived from student and faculty comments related to PBL. Students were asked to rate the extent to which they agreed with each statement using a five-point scale, where 1= strongly disagree and 5= strongly agree. Since students experienced traditional lectures for their basic science education in their first year of medical school and PBL for their second year of basic science curriculum, the second part of the questionnaire focused on students' comparisons of the two strategies in terms of achieving various educational goals. Twenty-three educational goals derived from the literature were listed; students were asked to indicate if PBL was more effective, less effective or equally effective to lectures in achieving each goal.

Analysis. The purpose of this study was to provide insight into students' opinions about the relative value of PBL compared to learning in a more familiar lecture format. Frequency distributions were used to describe students' responses. To assess changes in students' opinions after more experience with PBL, t-tests were used for the attitude questions and Chi-square values were calculated to test for change over time for the comparisons of PBL versus lectures in achieving each of the educational goals.

Results

Respondents. Eight-two students (85%) completed the anonymous questionnaire during the first administration. The response rate for the second administration was 83%. Since participation in the survey was voluntary and the questionnaire was anonymous, there was no means of determining the extent of any self-selection bias related to students' participation.

Attitudes about PBL. Students' attitudes about PBL from the first questionnaire administration are summarized in Table 1 ; the items are listed in order of increasing agreement. With the exception of the first item listed, at least half of the students agreed with the statements related to the value of PBL. Agreement among the students reached over 80% for some items. When the ratings for the items listed in Table 1 were compared between the fall and spring administration of the surveys, no significant differences were found. See website http://rapidintellect.com/AEQweb/win2006.htm For the first statement related to studying content lists, 28 students (35%) disagreed with the statement and 19 (24%) were unsure. This is the only negatively worded statement in terms of support for PBL. Students who disagreed could be interpreted as being supportive of PBL while students who agreed with the statement were more likely to be supportive of lectures over PBL. The negative association between this item and the statement "working in PBL group is more enjoyable than sitting in lecture" appears to support this interpretation (Chi-square= 17.84, df=4, p=.001).

PBL Compared to Lectures. Students' ratings of 23 educational goals, reflecting their views of the relative effectiveness of PBL or lectures in reaching these goals, are summarized in Table 2. The goals have been grouped into five broad categories: foundation for learning (N=9), learning efficiency (N=4), interpersonal skills (N=2), breadth of learning (N=5) and directing student learning (N=3). Overall, a majority of students endorsed lectures as more effective for four of the goals 23 listed and endorsed the effectiveness of PBL for 11 goals. Although not a majority, there were only two goals where the largest group of students rated lectures and PBL as equally effective. When the students' ratings from the fall and spring administration of the questionnaire were compared, no significant differences were found for any of the educational goals. See issue website http://rapidintellect.com/AEQweb/win2006.htm

Foundation for Learning. A majority of the students endorsed PBL as being more effective for seven of the nine goals listed within this category. For the goal "motivating me to learn new material" students were almost equally divided between endorsing PBL and rating PBL equally effective as lectures. In relation to preparing them for their first licensure examination, a majority of students endorsed the middle choice indicating that lectures and PBL were equally effective, with an additional one-third of the students endorsing lectures.

Learning Efficiency. For three of the four goals listed, a majority of students reported that lectures were more effective than PBL. For the goal "making connections between new and existing knowledge" most students rated PBL as superior to lectures.

Interpersonal Skills. For both goals listed within this category a majority of students endorsed PBL as more effective.

Breadth of Learning. PBL was reported to be superior to lectures by a majority of students for these goals related to enhancing the breadth and depth of learning, and linking basic and clinical science.

Directing Student Learning. Most students endorsed the effectiveness of lectures with regards to helping them focus on the right content. There was less consensus on the relative effectiveness of PBL versus lectures for giving students a sense of what they need to know. In contrast, a majority of students reported that PBL was the more effective strategy when addressing their own learning interests and needs. See issue website http://rapidintellect.com/AEQweb/win2006.htm

Individual Preferences for Lectures or PBL. For each respondent, a preference score was calculated as the number of educational goals where lectures were rated as being more effective subtracted from the number of goals for which PBL was endorsed. This preference score, which had a possible range from -23 to +23, was positive for students who endorsed PBL more frequently than lectures and was negative for students who more often indicated that lectures were more effective than PBL (Figure 1). The preference score had a mean of 5.5, with a median of 7.5 (mode = 8). Fifty-nine students (72%) had positive preference scores indicating support for PBL, whereas 22 students (27%) had preference scores less than zero indicating support for lectures.

Discussion

Given the structure of our curriculum, our second-year medical students have a unique vantage point to judge the problem-based learning as an educational strategy compared to more traditional lecture-based instruction. This survey of students suggests strong support for PBL as an educational approach: all of the attitude items demonstrated that students perceived the value of PBL. A majority of students found PBL more enjoyable than lectures and that it was a useful approach both for learning basic science as well as preparing students for their clinical rotations related to the care of patients. The discussions inherent in PBL groups were definitely seen to be valuable as a means of enhancing small group skills; the value of the content discussions themselves as a learning opportunity was less consistent among students.

Most students felt that PBL was superior to lectures for achieving a wide range of educational objectives. Despite the angst of students as they entered the PBL curriculum, most found it provided a valuable foundation for developing clinical problem solving skills required for their clinical education and later medical practice. This learning format was also endorsed as providing more interpersonal contact with instructors and classmates. Another area of strength for PBL was related to breadth of learning such as linking content across courses and applying learning to clinical problems.

Lectures were viewed as more effective than PBL in terms of learning efficiency and providing direction to the learner. Lectures helped students be more efficient in their use of study time, learning basic science knowledge, and providing students with a means of focusing their learning. Given the quantity of information confronting medical students, their desire for efficient learning strategies is understandable. Nonetheless, in many medical schools, PBL is valued despite the resources required because it promotes skills necessary for life-long learning, and part of learning these skills is to give students greater responsibility for their own learning.

That there was overall support for PBL was less of a surprise given that students seeking admission to the medical school knew about the PBL curriculum prior to matriculating and a certain amount of self-selection among students is likely. The magnitude of support was encouraging and helped to reassure faculty who might question the faculty hours required for of a small-group based curriculum for biomedical science instruction. There remained a small proportion of students who would have preferred a lecture format for their second year of medical school. For these students, lectures were more effective than PBL in achieving a wider range of educational goals. Despite their preference we could not determine if this made a difference in any aspects of their education. Since respondents were anonymous, identification of this subgroup of students in terms of prior experience with PBL, current academic achievement and preceptor ratings was not possible. Further research into students' preferences and their relationship to educational outcomes is desirable.

There were no significant changes in student attitudes towards PBL. The survey was administered to second year medical students late in the first semester and then repeated again in the second semester with the belief that students' attitudes and values related to PBL might change with experience. The findings suggest that the judgments made by students about PBL and the relative effectiveness of PBL versus lectures after 10 weeks of instruction did not change with further experience.

This study is limited in that it represents a single cohort of students from a single medical school. The extent to which these findings are generalizable to other institutions is unknown.

References

(1.) Kincade, S. A Snapshot of the status of problem-based learning in U.S. medical schools, 2003-2004. Academic Medicine. 2005; 80(3): 300-301.

(2.) Berkson, L. Problem-based learning: Have the expectations been met? Academic Medicine. 1993; 68 (10): S79-S87.

(3.) Dolmans, DHJM et al. Problem-based learning: future challenges for educational practice and research. Medical Education. 2005; 39:732-741

(4.) Prince, KJAH et al. General competencies of problem-based learning (PBL) and non-PBL graduates. Medical Education. 2005; 39:394-401

(5.) Distlehorst, LH, Dawson, E, Robbs, R. & Barrows, HS. Problem-based learning outcomes: The glass half-full. Academic Medicine. 2005; 80(3): 294-299.

(6.) Chamberlain, SE. & Searle, J. Assessing suitability for a problem-based learning curriculum: Evaluating a new student selection instrument. Medical Education. 2005; 39:250-257

Brian E. Mavis, Ph.D., Michigan State University, East Lansing, MI

Dianne P. Wagner, M.D., Michigan State University, East Lansing, MI

Dr. Mavis is Associate Professor and Director of the Office of Medical Education Research and Development; Dr. Wagner is Director of Problem-Based Learning