Effectiveness of problem-based learning curricula: research and theory

Introducing a problem-based unit into a lifespan nutrition class using a randomized design produces equivocal outcomes

Problem-based learning (PBL) is a tutorial, student-centered, problem-driven educational strategy adopted by medical and allied health educators to positively influence self-directed learning, critical thinking, and learning behavior. PBL was examined in dietetics education through random assignment of 32 undergraduate dietetics students for two weeks to either a problem-based or a lecture-based case format for the infant and elderly units of a 16-week lifespan nutrition course. Random assignment followed stratification for gender and earlier course examination performance. Expert validation of PBL curricular components and noted differences in discussion structure and information resources verified curriculum distinctiveness. Main outcome measures were pre- and post-Cognitive Behavior Survey scores for memorization, reflection, and positive learning experience scales, unit and course evaluations and unit examination scores. Students in problem-based modules demonstrated greater gains in reflective thinking with stable memorization, suggesting improved critical thinking skills. Tenets that problem-based learning promotes knowledge retention and provides a more positive learning experience were not upheld. Knowledge acquisition was not hindered by a problem-based approach. We conclude that gains in reflective thinking and evidence of increased self-directed learning argue for inclusion of PBL in dietetics curricula and that a problem-based education will help dietitians successfully respond to professional development needs.

Implementing a problem-based learning curriculum in an Argentinean medical school: implications for developing countries

The authors review the difficulties that Argentina's medical schools, particularly the public ones, are likely to face when implementing a problem-based learning (PBL) curriculum, describe the barriers that were faced by their medical school as it implemented PBL, and point out the implications for medical education in developing countries with conditions and education programs similar to those in Argentina. Specifically, they (1) outline the basic requirements for successful implementation of a PBL curriculum, (2) describe the training contradiction in Argentina between a complex and heterogeneous health care system that forces specialization and medical schools' attempts to train generalists, and (3) review the effects on curriculum change of the size and the training levels of the student population and the availability of human and financial resources. This information indicates the context in which the Rosario University School of Medicine designed a new PBL curriculum and implemented it in 2002. The authors close by suggesting that schools in developing countries that are in circumstances similar to that of Rosario should consider whether a PBL curriculum is even appropriate for them, and should realize the difficulties (discussed in the article) they will have to overcome. Also, uncertainties about the efficacy of PBL create a case for exploring alternatives to PBL, including hybrid curricula. Considering the available research on curricular innovations such as PBL and the particular situations of their countries may help schools anywhere avoid wrong decisions about what curricula to implement.

An operational measure of physician lifelong learning: its development, components and preliminary psychometric data

Despite the emphasis placed on physicians' lifelong learning, no psychometrically sound instrument has been developed to provide an operational measure of the concept and its components among physicians. The authors designed this study to develop a tool for measuring physician lifelong learning, to identify its underlying components and to assess its psychometric properties. A 37-item questionnaire was developed, based on a review of literature and the results of two pilot studies. Psychometric analyses of the responses of 160 physicians identified 19 items that were included in the Jefferson Scale of Physician Lifelong Learning. Factor analysis of the 19 items showed five meaningful factors that were consistent with the definition and major features of lifelong learning. They were 'need recognition', 'research endeavor', 'self-initiation', 'technical skills' and 'personal motivation'. The method of contrasted groups provided evidence in support of the validity of the five factors. The factors' reliability was assessed by coefficient alpha. It is concluded that lifelong learning is a multifaceted concept, and its operational measure is feasible for evaluating different educational programs and for studying group differences among physicians.

From case-based reasoning to problem-based learning

Many medical schools today are questioning whether they should implement a problem-based learning (PBL) curriculum. Educators have raised serious questions regarding the efficiency of PBL and therefore recommend learning more about the cognitive processes developed by PBL before implementing it broadly. In addition, it is important to determine whether PBL best matches the human reasoning process. The authors' theoretical discussion examines the relationship between the case-based reasoning (CBR) model and the PBL model. CBR indicates that the knowledge source one uses while solving a new problem includes not only generalized rules or general cases, but often a memory of stored cases recording specific prior episodes. CBR enables the reasoner to recommend solutions to problems quickly and to propose solutions in domains that are not completely understood, such as medicine. The authors' analysis reveals a strong association between the CBR and PBL models, and thus it can be argued that PBL is a successful teaching method that should be encouraged by medical schools.

USMLE performances in a predominantly Asian and Pacific Islander population of medical students in a problem-based learning curriculum

PURPOSE

To compare the USMLE performances of students of various ethnicities, predominantly Pacific Islander and Asian, at one medical school and to examine the predictive validity of MCAT scores for USMLE performance.

METHOD

A total of 258 students in the graduating classes of 1996-2000 at the University of Hawai'i School of Medicine were classified by ethnicity. Demographic and performance characteristics of the groups were examined, and MCAT scores with and without undergraduate science GPA were used to predict USMLE performance. Under- and over-prediction rates were computed for each ethnic group.

RESULTS

Ethnic groups did not differ significantly by gender or undergraduate GPA. Chinese, Caucasian, and Other Asian students tended to have higher MCAT scores than Hawaiian/other Pacific Islander, and Filipino students. Ethnic groups did not differ significantly in prediction of USMLE Step 1 performance. For Step 2, MCAT scores significantly over-predicted performance of Filipino students and tended to under-predict performance of Caucasian students.

CONCLUSION

Although MCAT scores and science GPA were good predictors of USMLE performance, ethnic differences were found in the degrees of their predictive validity. These findings both replicate and extend results of earlier studies, and again point to the importance of exploring additional predictor variables. The authors encourage future research on the effects of the following factors on success in medical school: reading and test-taking skills, socio-cultural and environmental influences on learning, communication styles, primary language use, family support, and family responsibilities.

Long-term follow up of factual knowledge after a single, randomised problem-based learning course

BACKGROUND

The long-term effect of problem-based learning (PBL) on factual knowledge is poorly investigated. We took advantage of a previous randomised comparison between PBL and traditional teaching in a 3rd year course to follow up factual knowledge of the students during their 4th and 5th year of medical school training.

METHODS

3rd year medical students were initially randomized to participate in a problem-based (PBL, n = 55), or a lecture-based (LBL, n = 57) course in basic pharmacology. Summative exam results were monitored 18 months later (after finishing a lecture-based course in clinical pharmacology). Additional results of an unscheduled, formative exam were obtained 27 months after completion of the first course.

RESULTS

Of the initial sample of 112 students, 90 participated in the second course and exam (n = 45, 45). 32 (n = 17 PBL, n = 15 LBL) could be exposed to the third, formative exam. Mean scores (+/- SD) were 22.4 +/- 6.0, 27.4 +/- 4.9 and 20.1 +/- 5.0 (PBL), or 22.2 +/- 6.0, 28.4 +/- 5.1 and 19.0 +/- 4.7 (LBL) in the first, second and third test, respectively (maximum score: 40). No significant differences were found between the two groups.

CONCLUSION

A small-scale exposure to PBL, applied under randomized conditions but in the context of a traditional curriculum, does not sizeably change long-term presence of factual knowledge within the same discipline.

Cancer knowledge and skills of interns in Australia and New Zealand in 2001: comparison with 1990, and between course types

OBJECTIVE

To compare the cancer knowledge and skills of interns in 2001 who graduated from graduate medical program (GMP) courses with those from non-GMP courses, and to compare the cancer knowledge and skills of interns in 2001 with those who completed a similar survey in 1990.

DESIGN

Questionnaire survey of recently graduated interns in a random sample of Australian and New Zealand hospitals. The questionnaire was designed to allow direct comparison with the 1990 survey, and was guided by the Australian Cancer Society's Ideal Oncology Curriculum for Medical Schools.

RESULTS

443 interns completed the survey (response rate, 62%; 42 were excluded, leaving 401 surveys for analysis: 118 from GMP courses and 283 from non-GMP courses). Interns from GMP courses felt more competent than those from non-GMP courses at discussing death (P = 0.02), breaking bad news (P = 0.04) and advising on smoking cessation (P = 0.02), but less competent at preparing a patient for a hazardous procedure (P = 0.02). More GMP interns would refer a breast cancer patient to a multidisciplinary clinic (83% versus 70%; P = 0.03). Knowledge about cancer risks and prognosis was significantly less in GMP interns, but GMP interns rated their clinical skills, such as taking a Pap smear, higher than non-GMP interns. The GMP and non-GMP groups did not differ in their exposure to cancer patients, but compared with 1990 interns recent graduates had less exposure to patients with cancer.

CONCLUSIONS

GMP curricula appear to have successfully introduced new course material and new methods of teaching, but have not always succeeded in producing doctors with better knowledge about cancer. Recent graduates have less exposure to cancer patients than those who trained 10 years ago.

Validation of an observation instrument for measuring student engagement in health professions settings

Documenting student engagement has received increased emphasis in medical schools, as teaching strategies are changing to include more student-to-student interactions. The purpose of this study was to develop and evaluate a measure of student engagement completed by independent observers that would not interfere with student learning time. Data from 3,182 observations completed by nine observers in 32 educational classroom settings with 23 different instructors were used to evaluate the interobserver reliability and gather validity evidence for our observational instrument, named the STROBE. Results indicated that interobserver agreement was good to excellent when observations were conducted simultaneously on randomly selected students in the same classroom (84% average agreement and 0.79 average kappa coefficient) and when observations were conducted on different randomly selected students (79% average agreement). Results also provided strong evidence for validity. Overall, findings indicate that the STROBE demonstrates promise for educational research and evaluation by documenting student engagement in medical education settings.

Small group learning in medical education: a second look at the Springer, Stanne, and Donovan meta-analysis

All in all, the evidence is not convincing. Only four of the nine randomized studies used the conventional small-group learning paradigm and qualify as studies of small-group learning, which are relevant to medical education. The results of one of the four are impossible to interpret because of the involvement of the investigator in teaching and test construction. The three remaining studies showed no effect, a negative effect, and a positive effect, respectively. The nonrandomized studies failed to establish the comparability of the groups. The evidence does not support the authors' call for "more widespread implementation of small-group learning in undergraduate SMET". Small-group learning has not been shown to support the acquisition of content any better [or worse] than large-group learning. In medical education, small-groups are employed in large part to develop team work skills, communication skills, and peer- and self-assessment skills. But these outcomes are not addressed in this meta-analysis. More seriously, our rereading of these studies raises general concerns about meta-analysis in education, which have important implications for evidence-based medical education. The meta-analysis under discussion at first appeared to be just the kind needed to guide an evidence-based educational enterprise. However, a closer look revealed both what is lacking in the meta-analysis and some of the ways educational research and reporting need to be changed if anything like evidence-based education is ever to become a reality. At the least, study design must be clearly described. In addition, if the design is nonrandomized, the groups should be described in sufficient detail to allow a meaningful interpretation of the role of preexisting differences on the outcome measures. (This is why we limited our discussion here to the randomized studies.) Also, effect-size measures should be reported for all comparisons that bear on the impact of the intervention, including preexisting differences. Reporting significance is not enough. This shows only whether sampling error can be ruled out (with a low probability of error, p < .05) as a possible explanation of the connection between the intervention and the outcome. The effect can still be trivial and the comparisons confounded. In addition, descriptions of the actual educational interventions employed need to be more comprehensive and precise. For the most part, the papers would have been strengthened by providing more information for replicating the studies and for deciding which should be included in a given meta-analysis. Perhaps most seriously, our rereading of these studies makes us wonder about the possibility of meaningfully synthesizing the results of educational studies, given their idiosyncrasies and their many extraneous, uncontrolled factors. The conclusions from most educational studies, then--whether randomized or not--must be highly qualified, with explicit warnings about preexisting differences and other confounding factors that plausibly account for the study results. However, these narrative qualifications do nothing to adjust the effect-size measures, which are typically pooled or synthesized across studies--confounds and all. The idiosyncrasies of the studies seem to preclude a blanket qualification that can be applied conceptually across the collection of studies to arrive at a sound conclusion from the synthesis. In brief, the meta-analysis considered here does not support the application of small-group learning in medical education and it raises questions about meta-analysis in education with implications for evidence-based education.

Challenges of current geriatric education-inspired by the Nordic geriatric professors' meetings

Geriatric educators are faced with several different challenges. The rapid growth of aged population in the Western world has led to a growing need for health and social services and thus, an increased need for trained professionals in this field. In addition, new learning theories and activating learning methods have achieved wide acceptance in academic medicine. How has geriatric education applied these new learning methods? In this article we review the current status of academic geriatric education in Western countries in these respects. We especially review the literature of how geriatric training has been experimenting with the new learning methods.

Support of a Problem-Based Learning Curriculum by Basic Science Faculty

Although published reports describe benefits to students of learning in a problem-based, student-centered environment, questions have persisted about the excessive faculty time commitments associated with the implementation of PBL pedagogy. The argument has been put forward that the excessive faculty costs of such a curriculum cannot be justified based upon the potential benefits to students. However, the magnitude of the faculty time commitment to a PBL curriculum to support the aforementioned argument is not clear to us and we suspect that it is also equally unclear to individuals charged with making resource decisions supporting the educational efforts of the institution. Therefore, to evaluate this cost - benefit question, we analyzed the actual basic science faculty time commitment in a hybrid PBL curriculum during the first phase 18 months of undergraduate medical education. The results of this analysis do demonstrate an increase in faculty time commitments but do not support the argument that PBL pedagogy is excessively costly in terms of faculty time. For the year analyzed in this report, basic science faculty members contributed on average of 27.4 hours to the instruction of medical students. The results of the analysis did show significant contributions (57% of instructional time) by the clinical faculty during the initial 18 months of medical school. In addition, the data revealed a four-fold difference between time commitments of the four basic science departments. We conclude that a PBL curriculu m does not place unreasonable demands on the time of basic science faculty. The demands on clinical faculty, in the context of their other commitments, could not be evaluated. Moreover, this type of analysis provides a tool that can be used to make faculty resource allocation decisions fairly.

Educational theory and medical education practice: a cautionary note for medical school faculty

Educational theory is routinely cited as justification for practice in medical education, even though the justification for the theory itself is unclear. Problem-based learning (PBL), for example, is said to be based on powerful educational principles that should result in strong effects on learning and performance. But research over the past 20 years has produced little convincing evidence for the educational effectiveness of PBL, which naturally raises doubts about the underlying theory. This essay reflects on educational theory, in particular cognitive theory, and concludes that the theory is little more than metaphor, not rigorous, tested, confirmed scientific theory. This metaphor/theory may lead to ideas for basic and applied research, which in turn may facilitate the development of theory. In the meantime, however, the theory cannot be trusted to determine practice in medical education. Despite the intuitive appeal of educational theory, medical educators have a responsibility to set aside their enthusiasm and make it clear to medical school faculty and administrators that educational innovations and practice claims are, at best, founded on conjecture, not on evidence-based science.

Evaluation of distance learning delivery of health information management and health informatics programmes: a UK perspective

The aim of the article is to review evaluations of distance learning programmes in health information management, in order to identify the critical success factors for such programmes and discuss future directions. The emphasis is on the UK experience, based partly on reflections on the experience of one programme at University of Wales Aberystwyth (now over 10 years old), and partly on a policy review conducted for the NHS Information Authority and the NHS Information Policy Unit. The methods are, as far as possible, those of a systematic review of existing research, with, additionally, an overview of relevant policy developments for lifelong learning. The topics covered include the aims, objectives and educational philosophies of the programmes. The evidence, combined with the UWA experience, indicates the importance of face-to-face interaction, to complement distance or virtual learning. A student-centred approach to curriculum design and delivery is essential.

Comparison of problem-and lecture-based pharmacology teaching

Problem-based learning (PBL) is gaining interest in many medical schools. Although various approaches have been labelled PBL, it remains unclear which approach is most appropriate for pharmacology courses. Moreover, some teachers remain sceptical about whether PBL is adequate to convey the numerous facts medical students need to memorize about drugs. However, comparisons of PBL methods with conventional lecture-based learning (LBL) methods within general pharmacology courses for medical students show that PBL students are at least as successful in standardized tests but enjoy their course to a greater extent than do LBL students.

Problem based learning in continuing medical education: a review of controlled evaluation studies

Reviews of undergraduate medical education cautiously support the short term and long term outcomes of problem based learning compared with traditional learning. The effectiveness of problem based learning in continuing medical education, however, has not been reviewed. This review of controlled evaluation studies found limited evidence that problem based learning in continuing medical education increased participants' knowledge and performance and patients' health. There was moderate evidence that doctors are more satisfied with problem based learning.

Perceptions of how well graduates are prepared for the role of pre-registration house officer: a comparison of outcomes from a traditional and an integrated PBL curriculum

INTRODUCTION

Most medical schools in the UK have been engaged in major curriculum reform based on their premises of what might improve undergraduate medical education. In 1994 the course at the medical school of the University of Manchester changed to an integrated course using problem-based learning throughout and with increased emphasis on community-based medical education. This study explores whether the new curriculum has produced any differences in perceptions of how well graduates are prepared for the role of pre-registration house officer.

METHODS

A postal questionnaire was used to survey 1998 Manchester graduates (traditional course) and 1999 Manchester graduates (new course), three months into their first pre-registration house officer placement. A similar questionnaire was sent to the educational supervisors who were supervising the graduates. The questionnaire was designed to measure perceptions of levels of preparedness for the role of pre-registration house officer, using a list of broad areas of competence and specific skills listed in the General Medical Council's 'The New Doctor'.

RESULTS

Graduates rated the new course significantly more effective for 12 of the 19 broad competences and eight of the 13 specific skills that were listed. The 'new' graduates rated their understanding of disease processes lower than the 'traditional' graduates, but there was no difference in the ratings given by the educational supervisors for this. Overall the educational supervisors rated the new course as better preparing graduates in five of the competences.

CONCLUSIONS

Overall, the evaluation shows that a major change in curriculum approach has changed the profile of the perceived preparedness of graduates for entering professional practice.

Differences between students in problem-based and lecture-based curricula measured by clerkship performance ratings at the beginning of the third year

BACKGROUND

Problem-based learning (PBL) is being incorporated into more medical curricula, but its influence on subsequent clinical performance remains unclear.

PURPOSE

To determine if PBL leads to better scores for fund of knowledge or clinical problem-solving skills in required clerkships taken early in the 3rd year at Penn State College of Medicine.

METHODS

Data were collected from 6 class years, for clinical clerkship subscores completed during the first 4 months of the 3rd year, of students completing 1 or 2 years in a PBL or traditional track. Clerkship scores were analyzed as individual clerkships and as the average across clerkships for each student. Statistical analysis included a comparison of clerkship scores between the 2 tracks; using a 2-sample t test, and calculation of effect sizes. A multiple regression model was also employed to adjust for age, gender, race, preadmission grade point average, and Medical College Admission Test (MCAT).

RESULTS

Mean scores of individual clerkships taken by problem-based or lecture-based students differed significantly in some clerkships, but the effect size was small. The effect sizes for fund of knowledge for the 6 clerkships ranged from 0.20 to 0.41; for clinical problem-solving skills, they ranged from 0.26 to 0.39. These differences between the problem-based and lecture-based students were of the same magnitude as the difference at the start of medical school on the MCAT, namely d = 0.31. There was a trend toward higher effect sizes in students having 2 rather than 1 year of PBL, and in later iterations of the track.

CONCLUSION

PBL effect size on students' scores for fund of knowledge and clinical problem-solving skills was small to moderate in various years.

Constructivism: the view of knowledge that ended philosophy or a theory of learning and instruction?

BACKGROUND

Constructivism is referred to in two very different ways in education including medical education: to refer to a view of knowledge and to refer to a theory of learning and hence instruction.

SUMMARY AND CONCLUSIONS

This proposal (a) distinguishes between these two usages of constructivism and (b) concludes that constructivism is not a theory of learning and thus as such has little to offer that might be of value to medical education.

To what degree do problem-based learning issues change with clinical experience?

BACKGROUND

Problem-based learning has been advocated for preclinical and clinical instruction because the learning issues are adaptable to students with varying previous knowledge and ranges of experience.

PURPOSE

The aim of this study was to evaluate whether the distribution in the types of learning issues generated to standardized problem-based learning cases changes with increasing clinical experience during the 3rd year of medical school.

METHODS

Learning issues collected for students performing their 3rd year family medicine clerkship were categorized into broad areas by three reviewers with agreement achieved through consensus and compared over time.

RESULTS

The distribution of learning issues remained relatively constant over the academic year with the exception of topics in the basic sciences and medical decision making. Basic science issues were more slightly common earlier in the 3rd year and decreased over time whereas the opposite trend was observed for medical decision-making questions.

CONCLUSION

This study suggests that students do generate different types of learning issues with more clinical experience. Students may show a very slight shift in interest from basic science concerns to higher-order medical decision-making issues over time, but the shift in this interest is very small.

Endocrine PBL in the year 2000

The Southern Illinois University School of Medicine (SIU-SOM) has utilized problem-based learning (PBL) in its curriculum since 1981, when Dr. Howard Barrows joined the faculty. From 1989 to 2000, SIU-SOM implemented two parallel curricula for the basic science years (years I and II), one curriculum being a problem-based learning curriculum (PBLC). An executive decision to design and implement a single curriculum, to begin in Fall 2000, fostered a review of existing pedagogy upon which to base this new curriculum: C2000. The results of this review, which considered formal outcome measures as well as internal review in consideration of the institutional mission, led to PBL becoming the predominant pedagogy for C2000, albeit with some modifications from its PBLC predecessor. C2000, then, represents the third iteration of PBL in use at SIU-SOM, and its design and rationale offer insight for the teaching of Endocrine Physiology in a PBLC.

Integration of neuroscience and endocrinology in hybrid PBL curriculum

At the University of Missouri-Columbia, the medical school employs a problem-based learning curriculum that began in 1993. Since the curriculum was changed, student performance on step 1 of the United States Medical Licensing Examination has significantly increased from slightly below the national average to almost one-half a standard deviation above the national mean. In the first and second years, classes for students are organized in classes or blocks that are 8 wk long, followed by 1 wk for evaluation. Initially, basic science endocrinology was taught in the fourth block of the first year with immunology and molecular biology. Student and faculty evaluations of the curriculum indicated that endocrinology did not integrate well with the rest of the material taught in that block. To address these issues, basic science endocrinology was moved into another block with neurosciences. We integrate endocrinology with neurosciences by using the hypothalamus and its role in neuroendocrinology as a springboard for endocrinology. This is accomplished by using clinical cases with clear neuroscience and endocrinology aspects such as Cushing's disease and multiple endocrine neoplastic syndrome type 1.

An interdisciplinary course in the basic sciences for senior medical and PhD students

Integrating clinical and basic sciences throughout the medical school curriculum has become a major objective of various innovations in medical education. While early clinical exposure has evolved as an efficient means of introducing clinical studies in the preclinical years, interdisciplinary integration of basic sciences during the clinical years remains a challenge. The authors describe their three years of experience with an interdisciplinary course designed to demonstrate the continuum of medical information from the clinic to the basic sciences. In this course, sixth-year medical students are required to choose one of three to four different one-week programs, each of which requires them to conduct an in-depth investigation of a defined clinical topic. Program coordinators are encouraged to work in clinician-basic scientist teams and to use a variety of teaching methods, with an emphasis on tutored individual and group learning based on critical readings of original papers. Coordinators are also encouraged to enable graduate research students to participate. From 1998 to 2000, students participated in nine programs, seven of which were coordinated by interdisciplinary teams. Several clinical and basic science disciplines were represented in each program, and various teaching methods were used. Graduate students participated in two of the programs. Evaluation of the programs (a debriefing discussion as well as short written evaluations) indicated moderate to good achievement of the course objectives.

Successful use of problem-based learning in a third-year pediatric clerkship

OBJECTIVE

To determine the effect of changing from lectures to a problem-based learning (PBL) curriculum on student knowledge accrual and satisfaction with the didactic portion of a clerkship.

DESIGN

Study of cohorts before and after PBL introduction and in comparison with unchanged medicine clerkship.

SETTING

Third-year pediatric clerkship at 5 clinical sites.

PARTICIPANTS

The PBL curriculum was introduced in the 1996 academic year. The 2 classes before the intervention served as historic controls (n = 319), whereas the 2 classes after PBL served as the intervention group (n = 320).

INTERVENTION

Small groups of students worked through 6 PBL cases representing common pediatric illnesses.

MAIN OUTCOME MEASURES

Knowledge was assessed with the pediatric and internal medicine subject examination of the National Board of Medical Examiners (NBME); student satisfaction was assessed by an anonymous end-of-rotation questionnaire.

RESULTS

Scores on the pediatric subject examination improved significantly from means of 69.2 and 70.0 in the historic control group to 73.6 and 74.2 in the PBL cohort (P <.01). Scores on the internal medicine subject exam during the same time periods remained unchanged until the second year after the change (69.1 and 70.2, respectively, before the change; 70.1 and 72.4, respectively, after the change). Analysis of variance results indicated a significant increase in pediatric subject examination scores associated with the introduction of PBL (P <.01). Overall student satisfaction with the pre-PBL lecture series was 3.3, whereas PBL sessions received a score of 4.3.

CONCLUSION

Use of PBL in a clinical clerkship was associated with higher scores on the NBME subject examination and increased student satisfaction. These results should encourage the use of PBL during the clinical years.

Changing face of medical curricula

The changing role of medicine in society and the growing expectations patients have of their doctors means that the content and delivery of medical curricula also have to change. The focus of health care has shifted from episodic care of individuals in hospitals to promotion of health in the community, and from paternalism and anecdotal care to negotiated management based on evidence of effectiveness and safety. Medical training is becoming more student centred, with an emphasis on active learning rather than on the passive acquisition of knowledge, and on the assessment of clinical competence rather than on the ability to retain and recall unrelated facts. Rigid educational programmes are giving way to more adaptable and flexible ones, in which student feedback and patient participation have increasingly important roles. The implementation of sustained innovation in medical education continues to present challenges, especially in terms of providing institutional and individual incentives. However, a continuously evolving, high quality medical education system is needed to assure the continued delivery of high quality medicine.

Effectiveness of problem-based learning curricula: theory, practice and paper darts

In a recent review article, Colliver concluded that there was no convincing evidence that problem-based learning was more effective than conventional methods. He then went on to lay part of the blame on cognitive psychology, claiming that 'the theory is weak, its theoretical concepts are imprecise. the basic research is contrived and ad hoc'. This paper challenges these claims and presents evidence that (a) cognitive research is not contrived and irrelevant, (b) curriculum level interventions are doomed to fail and (c) education needs more theory-based research.

Problem-based learning: why curricula are likely to show little effect on knowledge and clinical skills

OBJECTIVES

A recent review of problem-based learning's effect on knowledge and clinical skills updated findings reported in 1993. The author argues that effect sizes (ES) seen with PBL have not lived up to expectations (0.8-1.0) and the theoretical basis for PBL, contextual learning theory, is weak. The purposes of this study were to analyse what constitutes reasonable ES in terms of the impacts on individuals and published reports, and to elaborate upon various theories pertaining to PBL.

DESIGN

Normal theory is used to demonstrate what various ESs would mean for individual change and a large meta-analysis of over 10 000 studies is referred to in identifying typical ESs. Additional theories bearing upon PBL are presented.

RESULTS

Effect sizes of 0.8-1.0 would require some students to move from the bottom quartile to the top half of the class or more. The average ES reported in the literature was 0.50 and many commonly used and accepted medical procedures and therapies are based upon studies with ESs below 0.50.

CONCLUSIONS

Effect sizes of 0.8-1.0 are an unreasonable expectation from PBL because, firstly, the degree of changes that would be required of individuals would be excessive, secondly, leading up to medical school, students are groomed and selected for success in a traditional curriculum, expecting them to do better in a PBL curriculum than a traditional curriculum is an unreasonable expectation, and, thirdly, the average study reported in the literature and many commonly used and accepted medical procedures and therapies are based upon studies having lesser ESs. Information-processing theory, Cooperative learning, Self-determination theory and Control theory are suggested as providing better theoretical support for PBL than Contextual learning theory. Even if knowledge acquisition and clinical skills are not improved by PBL, the enhanced work environment for students and faculty that has been consistently found with PBL is a worthwhile goal.