Problem-Based Learning as a Teaching Method vs. The Traditional

Subject: Education
Pages: 15
Words: 4315
Reading time:
18 min
Study level: PhD


Problem-based learning (PBL) is a constructivist model of education in which learning is viewed as a process of active knowledge building rather than passive knowledge reception (Evensen & Hmelo, 2000). Constructivist theory holds that learners cannot passively absorb new information, but must incorporate it with pre-existing knowledge to build new ideas and concepts, a process profoundly affected by the context in which new information is encountered. These ideas are consistent with a philosophy of learning espoused by individuals such as John Dewey, Ernst von Glasersfeld, Jerome Brunner, and Howard Gardner. PBL first appeared as a distinct curricular method over 3 decades ago at Mc-Master University’s medical school in Hamilton, Ontario (Blake, 2000).Today, most medical schools in the United States and the world incorporate PBL into their curriculum to greater or lesser degrees (Makoul & Curry, 2000). PBL has been widely adopted in allied health and nursing education as well.

Study Purpose and Rationale

Purpose of Study

The purpose of this study was to determine if there were differences between PBL and traditional baccalaureate respiratory therapy curricula in terms of graduate and employer satisfaction ratings on standardized surveys, and national board examination scores. Traditional curricula were defined as those in which instructors provided the learning objectives and assignments, gave lectures to the entire class, conducted structured laboratories, and used mostly multiple-choice or other objective examinations to assess student learning.

Rationale of Study

This study is an investigation across institutions of PBL’s effectiveness, compared to traditional lecture-based strategies, in respiratory therapy education. To date, only one a few preliminary report has been published, in which NBRC examination scores were compared for consecutive graduating classes before and after conversion from a conventional to a PBL curriculum (Makoul & Curry, 2000). Likewise, few studies have been published that compare graduate and employer satisfaction with PBL and conventional respiratory therapy curricula in terms of the graduate’s cognitive competencies (e.g., ability to make sound clinical judgments and ability to recommend appropriate procedures) or affective competencies (e.g., effective communication ability, self directedness, ability to work effectively with supervisory personnel, professional-organization membership, and ethical/professional behavior). Improvement in these competencies and in graduate and employee satisfaction might justify PBL even if it does not improve board examination scores. This study also examined whether any of the measured variables (such as teaching-learning strategy or survey ratings in cognitive, psychomotor, and affective domains) are associated with performance on the national board examinations. The identification of such variables would provide insight into the measures program faculty might employ to maximize the probability of graduate success.

Research Questions

The following research questions were investigated.

  1. Were there significant differences between PBL graduates and traditional-program graduates in?
  2. Self-perceived cognitive, psychomotor, and affective competencies, as measured by the standardized Committee on Accreditation for Respiratory Care graduate satisfaction surveys?
  3. Employer-perceived graduate competencies in cognitive, psychomotor, and affective domains, as measured by the standardized Committee on Accreditation for Respiratory
  4. Care employer satisfaction surveys?
  5. Scores on the credentialing examinations administered by the National Board for Respiratory Care (NBRC)?

Literature review

The Problem-Based-Learning Philosophy

Problem-based learning’s most universal feature is the use of authentic, ill-structured, real-world problems to stimulate and organize all learning. It may be more appropriate to think of PBL as a philosophy than a specific teaching method. As a philosophy, PBL transforms the entire curriculum into a student-centered approach, emphasizing knowledge construction rather than knowledge transmission. Traditional teaching strategies emphasize the broad coverage of content areas through lecture, whereas the PBL method relies on the problem as a vehicle to guide learners to relevant content information. As Boud succinctly stated, “The principal idea behind problem-based learning is… that the starting point for learning should be a problem, query, or puzzle that the learner wishes to solve (Boud, 1985).” This philosophy of learning fundamentally challenges the traditional assumption that information should be acquired before problem-solving can begin, and that learning should be sequential, progressing from basic scientific concepts to clinical application (Evensen & Hmelo, 2000). Traditional lecture based courses tend to emphasize teaching rather than learning, passive rather than active learning, and having rather than creating knowledge. Barrows has been credited with developing the classic model of PBL in medical education.

PBL Implementation

There are a number of practical applications of PBL in action (Blake, 2000). An example of a common form is given below in which a series of weekly cases of increasing complexity act as a central resource for tutorial discussions and for self-directed study. The cases are supplemented by regular lectures, lab sessions, conferences, computer-aided learning, visits and projects in the hospital or community as appropriate. This wide experience offers a variety of perspectives on the main instructional theme of the week and encourages the student to think across the subject rather than focusing on single or solitary aspects of it.

The tutorial discussion is the engine that drives PBL. Each week two tutorials take place, one at the beginning to set the theme in action and one towards the end as a follow-up session. There may also be periodic ‘time-out’ sessions to check on progress, spot problems and deal with group interaction issues. The process is varied but usually groups of six or seven students work together with a tutor (Dyke & Jamrozik, 2001). The tutor need not be a subject specialist as he or she is not called on to act as a resource. Instead the tutor acts as a guide and helper as the student’s progress through the discussion and decision making required to find a solution to the problem presented. The group usually elects a note-taker responsible for recording the main items of the discussion on a board or flip chart. These items are used to define the learning activities that the group will subsequently undertake, whether alone or together, before the next meeting. A summary of the topics covered provides a useful synopsis of the work carried out by the group over a term and can be used in curriculum evaluation (Kaufman, & Mann, 1996). The tutor starts the session with a presentation of the problem. This may take the form of a written case, a videotape or an audio recording. Students are expected to organize their thoughts (about the problem) and to attempt to identify the general nature of the problem and the factors involved. After brainstorming on the underlying causes, mechanisms, and possible solutions, areas of uncertainty or ignorance are recorded on a flip chart. The group is then encouraged to examine the recorded suggestions in greater detail (Dyke & Jamrozik, 2001). During the discussion, further questions that the students do not understand or do not know about emerge and these are also recorded on the flip chart. Before the end of the session the tutor helps the students to concentrate on the questions that are especially important at their current stage of training. The students then decide which of the questions they will follow up, individually or as a group. At the second session the students are encouraged to reflect on what they have learned by answering the questions left on the flip chart from the earlier session. They explore each others answers to the questions and consequently, teach themselves and compare their own performance with that of their peers. The new knowledge and understanding acquired in this process is applied to solving the original problem and the earlier hypotheses considered, rejected or refined accordingly. Definitive resolution of the problem is not necessary, especially in the early part of the course.

In seeking the answers to problems raised during the tutorial discussions, the student’s learn how to obtain information from various sources including experts, libraries and computer resources and in the tutorial at the end of the week they learn how to question information critically. The method encourages active use of what has been learned and provides instant feedback on how well newly acquired information has been assimilated. The group is able to develop their own questions about the problem and to seek their own answers. This new information is then integrated with existing personal knowledge and with the knowledge of the group in trying to formulate a solution. Observers of PBL sessions emphasize that the atmosphere should be, and usually is, non-competitive with students working together to find solutions.

PBL In medicine

In an Australian radiation therapy program based on PBL, at end year completion, students filled questions about PBL, learning processes, assessment of work and resources availability. The program registered negative interests among learners (99.25) despite showing interdependence to learner’s achievement. Despite the results indicating independence of learners had been achieved and that the aims of the program were met, around 69.2% of learners did not find the program interesting to their learning. Most learners felt thst it was a difficult learning technique that required more than just implementation. Resources availability is a major constraint that most respondents cited as an obstacle to its success. Up to 57.75 of learners expressed some form of frustration with this learning approach, majority of whom cited resources as the cause of their frustration (Beers, 2006). In essence, the research noted that the problem based learning approach is interactive and hence requires a bulk of resources. Further the research proposed that the program be reserved for final year students who have underwent relative maturity (Beers, 2006).

In another study performance based on traditional learning methods and problem based learning was conducted amongst chiropractic students (Berkson, 1993). Astonishingly, no significant variations were recorded. Notably, a lot of frustration was expressed with regard to problem based learning methodology. Such frustrations included confusion regarding faculty-student expectations, faculty inadequacy, and learner’s tutorials and individualized learning strategies, and inappropriate integration into curricular, context of learning and inadequate learning duration (Berkson, 1993; Prideaux, 2004). Another study aimed at establishing whether PBL was an adequate learning strategy for nursing students using ethical dilemmas as problems yielded confirmatory results. The strategy included knowledge sharing, enhanced decision making capabilities, and improved critical thinking. This is evidenced by the value changes from post to pre-test results. The research affirmed that PBL is an appropriate learning approach nursing students in ambulatory care services (Maudsley, 2001).

In another research on Nutrition and Dietetics program, problem based learning approach was critically evaluated (Bovee, 2004). The overlal academic performance and student perceptions as well as hospital supervisory team were considered. Despite the fact that not siginifcat results were recored, PBL content was found to be more relevant and in line with contemporary practice (Bovee, 2004). Additional a decline in number of students in need of placement for competency declined significantly.

In an occupational therapy program aimed at establishing the effects of PBL course on clinical reasoning development, similar results were obtained (Colliver, 2000). A quasi experimental design involving post pre and post-tests was conducted using a group of 48 senior students. The course schedule was undertaken prior to a planned field work. In assessing, reasoning within clinical perspective, Self-Assessment of Clinical Reflection and Reasoning (SACRR) was employed (Colliver, 2000). The instrument basically relies on perceptions of the subject with regard to clinical reasoning techniques and character rather than evaluating performance. Statistically significant results were observed In PBL implementation and students asserted that they had improved their clinical reasoning capabilities.

The approach is however not without disbenefits/disadvantages. It is time consuming and content coverage may not be easy to achieve (Berkson, 1993). Its implementation would also render some parts of the existing curriculum redundant and in need of reorganization. This will require that the faculty re-evaluates the existing curriculum and come with new assessment scenarios and criteria (Berkson, 1993).

Problem-based learning (PBL) is an important and widely discussed development in medical education and forms the basis of the curricula of many newly established medical schools throughout the world. A number of universities are incorporating the principles of PBL into their own curricula. It is mainly used in the undergraduate setting and, as a result of General Medical Council recommendations; many new graduates will have experienced it in one form or another (Neufeld & Barrows, 1974). PBL is concerned with both what students learn and how they learn it, and uses specially prepared problems, usually written cases derived from clinical experience, as the basis of the curriculum (Neufeld & Barrows, 1974; Chen, 2000). Students may use this case to stimulate their learning of anatomy and physiology during the early parts of their course by finding explanations for the source, distribution and underlying physiological process of the pain (Norman, 2000).

The approach used at Liverpool encourages students to consider their learning issues as elements of four curriculum themes. PBL is an approach first used in medicine but which can now be found in many teaching settings including architecture, nursing, engineering and social work. The method uses tutorial discussion groups supplemented by traditional teaching methods to stimulate active learning on the parts of students. The problems chosen are derived from clear course objectives and are sensitive to the level of sophistication of the student at different stages of training (Neufeld & Barrows, 1974). PBL started in North America where medical teachers, concerned about curriculum overload and inappropriate teaching methods, shifted the emphasis of the undergraduate curriculum away from individual disciplines such as biochemistry, anatomy and physiology towards an integrated approach involving students in problem solving and independent learning, often from the first term (Neufeld & Barrows, 1974; Richards, 2003). Critical reflection on evidence and about its use in working on problems is at the heart of PBL and is a central requirement for effective learning. Implications of PBL for medical teachers

For the traditional medical teacher, PBL means less lecturing but more student contact in the form of small group work and self-directed learning (Spaulding, 1991). It means that lectures do not need to be prepared and updated each year but it does call for different skills, particularly those of group leadership. The design and development of PBL trigger material takes time and planning that should not be underestimated especially when starting afresh. It also requires careful discussion with medical teachers and organizers to ensure that the material is relevant, practical and clearly related to objectives for teaching (Spaulding, 1991; Mishoe & MacIntyre, 2001). Such discussions can be very fruitful in developing shared understanding between, for example, basic science, hospital and community teachers.

PBL encourages the learner to work on problems for himself. There is often initial surprise at not having to memorize tracts of isolated information and discomfort at the prospect of discovery rather than passive learning (Mishoe, 1993). The challenge of integrating experiences, previous knowledge, skill and activities with new knowledge and using this to solve clinically related problems, is stimulating for many students and is most appropriate in a community setting (Spaulding, 1991). PBL offers the opportunity to integrate psychosocial elements into the student’s thinking about medical problems helping to develop ‘three dimensional’ thinking, although research at Maastricht suggests that students need clear ‘psychological triggers’ in such cases (Camp, 1996).

Many teachers see PBL as a method for developing active and independent learners, creative and divergent thinkers and good communicators (Edens, 2002). They hope Problem-based learning in medicine students learn by analyzing selected clinical problems, students work in tutorial groups recording key areas for learning, learning is active and student-directed, self-directed learning skills are developed and enhanced teachers guide and facilitate rather than direct, discovery and application of knowledge emphasized over recall, assessment focuses on clinical, reasoning and self-directed learning as well as recognition and recall of facts (Mishoe, 1997). The product of a problem-based curriculum will be a doctor well versed in group problem-solving, capable of working well on his or her own, competent at using literature and statistical databases to retrieve information and confident in his own professional ability. But is this the case?

Evaluation of PBL produces equivocal results. A review of over 100 papers published between 1972 and 1992, found that, compared to conventional teaching, PBL was more enjoyable and supportive and that graduates who had experienced it ‘performed as well, and sometimes better, on clinical examinations, and were more likely to enter family medicine’ (Mishoe, 1997). The review also found that medical teachers enjoyed teaching using PBL. The authors draw attention to the need for further work determining the costs ofPBL compared to conventional teaching and to its effects on students’ reasoning processes suggesting that, for some students, important gaps in knowledge might occur.

Using psychometric methods, some differences have been suggested between students, with a tendency for those learning within a traditional curriculum to score more highly on measures of superficial learning whilst those in PBL-based courses score better on measures of ‘deeper’ learning of understanding (Op’t Holt, 2000). Norman and Schmidt” reviewed the experimental literature concerning the psychological basis of PBL and concluded that, whilst general problem-solving skills were not enhanced by a PBL course, the knowledge learned during such a course was better retained (Major & Palmer, 2001). They also suggested that integration of basic science into clinical concepts and the use of knowledge in the clinical context was improved and that both intrinsic motivation to learn and self-directed learning (Op’t Holt, 2000). Skills were substantially enhanced by PBL courses. They report that students in a PBL environment find the ‘learning environment more stimulating and humane that do graduates of conventional schools’. Comparisons between students in PBL and conventional courses are difficult because conventional testing instruments are geared towards traditional teaching methods and so test knowledge recall rather than application and problem solving. Perhaps the most significant finding is the high levels of enjoyment and satisfaction recorded by both teaching staff and students in problem-based programs (Op’t Holt, 2000); compared with current levels of dissatisfaction experienced by students in conventional curricula’ this finding alone makes an exploration of the potential of PBL essential.

Recently, many professions, including medicine, nursing, and allied health, have incorporated problem solving, decision making, and critical thinking into their curriculums (Mishoe, 1993). The growing use of therapist-driven protocols, or respiratory care protocols, makes skills of this nature essential for effective practice. This suggests further emphasis in the respiratory care curriculum should be placed on skills requiring professional judgment (Mishoe & MacIntyre, 1997). In 1992, the results of the National Consensus Conference on Respiratory Care Education suggested a greater emphasis on communication, critical thinking, and problem-solving skills will be necessary for the respiratory therapist of the future (Cullen et al., 1992). Numerous studies have documented that respiratory therapists can be more effective than other health care personnel in allocating respiratory care services, especially when protocols are in place (Mishoe & MacIntyre, 1997). The increasing knowledge base, increased emphasis on assessment and decision-making skills, and limited time to teach these critically important skills leave educators with a sense of frustration and urgency in designing curriculum. The National Board for Respiratory Care (NBRC) provides one extremely valuable resource for curriculum design: a detailed content outline, or test matrix, for the credentialing examinations they administer (National Board for Respiratory Care, Inc. [NBRC], 1998).

PBL in respiratory based therapy

Beachey conducted a mixed mixed-methodology study was to determine if there are differences between PBL and traditional respiratory therapy curricula in terms of graduate and employer satisfaction ratings on standardized surveys and national board examination scores. The retrospective study was focused on baccalaureate-level respiratory therapy education, not only because it helped control for confounding variables, but also because of the limited use of PBL in respiratory therapy education. Problem-based learning as a teaching strategy and curricular design began over 30 years ago at McMaster University in Canada. Applying problem based approach on basis of real clinical scenarios has greatly evolved medical education evolved after lengthy period of frustration and complex clinical experiences. PBL has altered curriculum of medical courses from faculty centered to student focused involving interdisciplinary coordination. The emphasis of PBL is based on learning (what students do), rather than teaching (what the faculty do). PBL has further been proposed as a strategy not only for preparing students, but also for continuing education to expand professional roles for respiratory therapists (Hay & Katsikitis, 2001). In addition, relationships between PBL, critical thinking, and evidence based medicine have been described for respiratory therapy education and practice (Mishoe & Hernlen, 2005).

The continued PBL application in health care and higher education is a product of recognition that retain minimal information when traditional didactic teaching methods are employed and further have difficulty transferring knowledge to new experiences they meet later in practical applications (Mishoe & Hernlen, 2005). PBL offers an environment where students can utilize knowledge learnt in the real-world context, and further reinforce the knowledge with logical reasoning. Introductions to PBL with specific applications and cases in respiratory therapy have been published and promoted (Mishoe & Welch, 2001). Although there are many variations and applications of PBL from the McMaster or “purist” approach to case-based approaches, the emphasis on these elements are generally consistent: learning organized around problems or cases; student-directed, active learning; development of the learner’s communication skills; consideration of the continuum of wellness to illness; and, attention to biological, clinical, psychosocial, ethical, financial, and practical issues (Mishoe, 2003).

Problem-based learning is an applicable framework in curriculum development. From experiences with PBL in physical therapy, there has been a shift from an entire curriculum using the purist PBL approach to a hybrid, case-based approach to maximize faculty resources. In our respiratory therapy program we have incorporated a variety of PBL approaches, including one course using the McMaster PBL, hybrid PBL courses, and case-based approaches. The variations in case based and PBL is not easy to assert though. In a study evaluating expert and non-=expert tutors, Hay and Katsikitis showed that the two have no differences (Beachey, 2007). The only mentionable difference is that problem is supported by materials and questions while in pure problem based scenarios the problem is expected to stimulate students reasoning and come with solutions.

No studies have been published comparing graduate and employer satisfaction with PBL and conventional respiratory therapy curricula based upon the graduate’s cognitive competencies (eg, ability to make sound clinical judgments and ability to recommend appropriate procedures) or affective competencies (eg, effective communication ability, self-directedness, ability to work effectively with supervisory personnel, professional organization membership, and ethical/professional behavior). This study also examined whether any of the measured variables (such as teaching learning strategy, or survey ratings in cognitive, psychomotor, and affective areas) are associated with performance on the national board examinations. Beachey’s findings are consistent with the literature, in which many studies confirm that PBL graduates perform as well on standardized examinations as graduates prepared by conventional methods, are generally more satisfied with their educational experience, and are more self-directed in the course of their studies (Beachey, 2007). However, Beachey’s findings on employer ratings were not consistent with other studies. For example, a very recent study comparing critical thinking and communication skills during a dental residency found that dental residents prepared using PBL were rated significantly higher in communication with patients, critical thinking, and independent learning, performance in small groups, self assessment, and teamwork (Fraser, 2001). Although Beachey found no significant differences in the overall employer ratings for either group, there were some differences reported by item. The literature does not support the unexpected finding in this study that the employers rated the PBL graduates lower on some of the survey items, such as communicating effectively. As Beachey points out “it is especially difficult to explain why employers would rate PBL graduates lower as effective communicators than traditional graduates, considering the predominant role communication skills play in small-group PBL methods.” Beachey’s findings and explanations may indeed be a reflection on reactions to graduates who have been prepared to question, and on how the role of questioning is viewed relative to other attributes, such as teamwork, in respiratory therapy. Other possibilities to explain any differences may be lack of interraterreliability, as well as differences in sample sizes, with a much larger percentage of surveys (78%) received for traditional graduates than those received for PBL graduates (42%).

The problems in applying the scientific method that is typically used in clinical research to educational research are well known and difficult to overcome. Most respiratory care programs have too small a class size to conduct a study within a narrow time frame, consistent with academic calendars. Multi-program studies, as conducted by Beachey, help address the issues when class sizes are small; however, it opens up a different set of variables, such as standardizing the “treatment,” which in this case is PBL, and its effects on the outcomes (Thammasitboon, 2007).

Even graduate outcomes, including cognitive, psychomotor and affective, are rater-dependent and extremely hard to assess from multiple employers, even when the instruments are standardized. Researchers disagree about whether educational experiments can illuminate the effects of a curriculum-level intervention such as the application of PBL. Many maintain that interventions at the curriculum level can never be uniform, are impossible to blind, and cannot achieve an unadulterated outcome attributable only to the intervention (Smits, 2006; Farrow & Norman, 2003; Dolmans, 2003). In addition, objective student assessment methods based on traditional methods, such as multiple-choice examinations, may not be sensitive to PBL’s effectiveness. Despite the limitations, researchers, predominantly in medical education, have conducted numerous studies comparing PBL’s outcomes with those of conventional lecture-based instruction. Beachey’s publication is an important contribution to the respiratory care literature because it provides specific findings on the influence of PBL in respiratory therapy, albeit with the limitations that he addresses.

There is for further study of the effectiveness of PBL to prepare respiratory therapy graduates with the knowledge and skills needed to practice respiratory care. The limited use of PBL in respiratory care, the lack of published studies, and the limitations of educational research have made it difficult to draw solid conclusions. Additional uses of PBL and educational research comparing PBL to traditional methods are needed to determine whether PBL is having any real influence in respiratory care.


Albanese, M. A. & Mitchell, S. (1993). Problem-based learning: a review of the literature on its outcomes and implementation issues. Acad Med, 68(1), pp. 52–81.

Beachey, W. A. (2007). Comparison of problem-based learning and traditional curricula in baccalaureate respiratory therapy education. Respir Care, 52(11), pp. 1497–1506.

Beers, G. W. (2006).The effects of teaching method on objective test scores: Problem-based learning versus lecture. J Nurs Educ, 44(7), pp. 305–309.

Berkson, L. (1993). Problem-based learning: have the expectations been met? Acad Med, 68(10 Suppl), pp. S79–S88.

Blake, R. L, (2000). Student performance on step 1 and step 2 of the United States medical licensing examination following implementation of a problem-based learning curriculum. Acad Med, 75(1), pp. 66–70.

Boud, D. J. (1985). Problem-based learning in perspective. In, pp. Boud DJ, editor. Problem-based learning in education for the professions. Sydney, pp. Higher Education Research and Development Society of Australasia, 13.

Bovee, M. L. (2004). Effects of contrasting equivalent teaching approaches on student ratings. J Allied Health, 33(1), pp. 70–74.

Camp, G. (1996).Problem-based learning, pp. a paradigm shift or a passing fad? Med Educ, 1 (2). Web.

Chen, S. E. (2000). Problem-based learning, pp. educational tool or philosophy? Post-conference proceedings from the 2nd Asia-Pacific conference on problem-based learning. Singapore.

Colliver, J. A. (2000). Effectiveness of problem-based learning curricula, pp. research and theory. Acad Med, 75(3), pp. 259–266.

Dolmans, D. (2003).The effectiveness of PBL, pp. the debate continues. Some concerns about the BEME movement. Med Educ, 37(12), pp. 1129–1130.

Dyke, P. & Jamrozik, K. (2001). A randomized trial of a problem-based learning approach for teaching epidemiology. Acad Med, 76(4), pp. 373–379.

Edens, K.M. (2002). Preparing problem solvers for the 21st century through problem-based learning. College Teaching, 48(2), pp. 55–60.

Evensen D. & Hmelo C. E. (2000). Problem-based learning, pp. a research perspective on learning interactions. Mahwah (NJ), pp. Lawrence Erlbaum Associates; 2000.

Farrow, R. & Norman, G. (2003).The effectiveness of PBL, pp. The debate continues. Is meta analysis helpful? Med Educ, 37(12), pp. 1131– 1132.

Fraser, S. W. (2001). Coping with complexity, pp. educating for capability. BMJ, 323(7316), pp. 799–803.

Hay, P. J. & Katsikitis, M. (2001). The expert in problem-based and case-based learning, pp. necessary or not? Med Educ, 35(1), pp. 22–26.

Kaufman, D. M. & Mann, K. V. (1996). Comparing students’ attitudes in problem- based and conventional curricula. Acad Med, 71(10), pp. 1096–1099.

Major, C. H. & Palmer, B. (2001). Assessing the effectiveness of problem-based learning in higher education, pp. lessons from the literature [electronic version]. Academic Exchange Quarterly, 5, pp. 4–9.

Makoul, G. & Curry, R. H. (2000). Thompson JA. Gauging the outcomes of change in a new medical curriculum: students’ perceptions of progress toward educational goals. Acad Med, 75(10 Suppl), pp. S102–S105.

Maudsley, G. (2001).What issues are raised by evaluating problem-based undergraduate medical curricula? Making healthy connections across the literature. J Eval Clin Pract, 7(3), pp. 311–324.

Mishoe, S. C. & Hernlen, K. (2005).Teaching and evaluating critical thinking. Respir Care Clin N Am, 11(3), pp. 477–488.

Mishoe, S. C. (1993). Critical thinking, educational preparation and development of respiratory care practitioners. Distinguished Papers Monograph, 2(1), pp. 29–43.

Mishoe, S. C. (1997). Can respiratory therapy education improve critical thinking? Respir Care, 42(11), pp. 1078.

Mishoe, S. C. (2003).Critical thinking in respiratory care practice, pp. a qualitative research study. Respir Care, 48(5), pp. 500–516.

Mishoe, S.C, & Welch, M. A Jr. (2001). Critical thinking in respiratory care, pp. a problem-based learning approach. New York: McGraw-Hill.

Mishoe, S.C., & MacIntyre, N. R. (2001). Expanding professional roles for respiratory care practitioners. Respir Care, 42(1), pp. 71–91.

Neufeld V. R. & Barrows H. S. (1974).The “McMaster philosophy”: an approach to medical education. J Med Educ, 49(11), pp. 1040–1050.

Neufeld, V.R, & Barrows, H.S. (1974).The “McMaster philosophy”, pp. an approach to medical education. J Med Educ, 49(11), pp1040–1050.

Norman, G. (2003). RCT results confounded and trivial, pp. the perils of grand educational experiments. Med Educ, 37(7), pp. 582–584.

Norman, G. R. (2000). Effectiveness of problem-based learning curricula, pp. theory, practice and paper darts. Med Educ, 34(9), pp. 721–728.

Op’t Holt, T. B. (2000). A first year experience with problem-based learning in a baccalaureate cardio-respiratory care program. Respir Care Education Annual, 9, pp. 47–58.

Prideaux, D. (2004). Researching the outcomes of educational interventions, pp. a matter of design. BMJ, 324(7330), pp. 126–127.

Prince, K. J. et al. (2005). Does problem-based learning lead to deficiencies in basic science knowledge? An empirical case on anatomy. Med Educ, 37(1), pp. 15–21.

Quinlan, K. M. (2003). Effects of problem-based learning curricula on faculty learning, pp. new lenses, new questions. Adv Health Sci Educ Theory Pract, 8(3), pp. 249–259.

Richards, L. V. (2003). Evaluation in medical education, pp. moving forward. Med Educ, 37(12), pp. 1062–1063.

Smits, P. (2006). Problem based learning in continuing medical education: a review of controlled evaluation studies. BMJ, 324(7330), pp. 153–156.

Spaulding W. B. (1991). Revitalizing medical education, pp. McMaster medical school, the early years 1965–1974. Philadelphia, pp. B.C. Decker; 1991.

Thammasitboon, K. (2007). Problem based learning at the Harvard school of dental medicine, pp. self assessment of performance in postdoctoral training. J Dent Educ, 71(8), pp. 1080–1090.

Vernon, D. T. (1993).Does problem-based learning work? A meta-analysis of evaluative research. Acad Med, 68(7), pp. 550–63.