Problem-based learning (PBL) is a student-centered pedagogy in which students learn about a subject in the context of complex, multifaceted, and realistic problems. Working in groups, students identify what they already know, what they need to know, and how and where to access new information that may lead to resolution of the problem. The role of the instructor is that of facilitator of learning who provides appropriate scaffolding of that process by (for example), asking probing questions, providing appropriate resources, and leading class discussions, as well as designing student assessments.
PBL was pioneered in the health sciences at McMaster University in the late 1960’s and subsequently it has been adopted by other medical school programs (Barrows, 1996) and also been adapted for undergraduate instruction (Boud and Feletti, 1997; Duch et al., 2001; Amador et al., 2006). The use of PBL, like other student-centered pedagogies, has been motivated by recognition of the failures of traditional instruction (Wingspread, 1994; Boyer, 1998) and the emergence of deeper understandings of how people learn (National Research Council, 2000). Unlike traditional instruction, PBL actively engages the student in constructing knowledge in their own mind by themselves, and thus addresses many of deficits of traditional classroom where knowledge is expounded by an instructor.
Characteristics of PBL are:
- Learning is driven by challenging, open-ended, ill-defined and ill-structured problems.
- Students generally work in collaborative groups.
- Teachers take on the role as “facilitators” of learning.
In PBL, students are encouraged to take responsibility for their group and organize and direct the learning process with support from a tutor or instructor. Advocates of PBL claim it can be used to enhance content knowledge while simultaneously fostering the development of communication, problem-solving, and self-directed learning skills.
PBL may position students in a simulated real world working and professional context which involves policy, process, and ethical problems that will need to be understood and resolved to some outcome. By working through a combination of learning strategies to discover the nature of a problem, understanding the constraints and options to its resolution, defining the input variables, and understanding the viewpoints involved, students learn to negotiate the complex sociological nature of the problem and how competing resolutions may inform decision-making.
Evidence supporting problem-based learning
Hmelo-Silver, Duncan, & Chinn cite several studies supporting the success of the constructivist problem-based and inquiry learning methods. For example, they describe a project called GenScope, an inquiry-based science software application. Students using the GenScope software showed significant gains over the control groups, with the largest gains shown in students from basic courses.
Hmelo-Silver et al. also cite a large study by Geier on the effectiveness of inquiry-based science for middle school students, as demonstrated by their performance on high-stakes standardized tests. The improvement was 14% for the first cohort of students and 13% for the second cohort. This study also found that inquiry-based teaching methods greatly reduced the achievement gap for African-American students.
A systematic review of the effects of problem-based learning in medical school on the performance of doctors after graduation showed clear positive effects on physician competence. This effect was especially strong for social and cognitive competencies such as coping with uncertainty and communication skills.
Examples of applying Problem-Based Learning pedagogy to curriculum
In Malaysia, an attempt is being made to introduce a hybrid of problem-based learning in secondary mathematics called PBL4C, which stands for problem-based learning the four core areas in the mathematics education framework. These core areas are content, thinking processes, skills, & values, with the aim of nurturing wise citizens who are responsible in decision-making for sustainable development. This hybrid first sprouted in SEAMEO RECSAM in 2008 and a paper was presented at the EARCOME5 conference in 2010. At tertiary level, many Malaysian universities are going for PBL purposely to improve the quality of the graduates produced. In collaboration with Aalborg University of Denmark, PBL was introduced at University Tun Hussein Onn Malaysia (UTHM). Since then the PBL was widely used among engineering and as well as humanities lecturers at UTHM (Berhannudin, 2007).
Several medical schools have incorporated problem-based learning into their curricula, using real patient cases to teach students how to think like a clinician. More than eighty percent of medical schools in the United States now have some form of problem-based learning in their programs. Research of 10 years of data from the University of Missouri Medical School PBL curriculum supports PBL. ( Koh GC-H, Khoo HE, Wong ML, Koh D. The Effects of Problem-based learning during medical school on physician competency: a systematic review. CMAJ 2008;178(1):34-41.)
Maastricht University offers its whole program in PBL format only, as does the University of Limerick Graduate entry medical school in Ireland.
In 2004, the Lake Erie College of Osteopathic Medicine founded a branch campus in Bradenton, Florida, utilizing an entirely PBL format. From 2006-2010, this campus led the nation in COMLEX scores.
Constructivism and PBL
From a constructivist perspective Problem-based learning (PBL), the role of the instructor is to guide the learning process rather than provide knowledge (Hmelo-Silver & Barrows, 2006). From this perspective, feedback and reflection on the learning process and group dynamics are essential components of PBL. Students are considered to be active agents who engage in social knowledge construction.
Criticisms of Problem-based learning
Problem-based learning and cognitive load
Sweller and others have published a series of studies over the past twenty years that is relevant to problem-based learning but concerning cognitive load and what they describe as the guidance-fading effect (Sweller, 2006). Sweller, et al. conducted several classroom-based studies with students studying algebra problems (Sweller, 1988). These studies have shown that active problem solving early in the learning process, is a less effective instructional strategy than studying worked examples (Sweller and Cooper, 1985; Cooper and Sweller, 1987). Certainly active problem solving is useful as learners become more competent, and better able to deal with their working memory limitations. But early in the learning process, learners may find it difficult to process a large amount of information in a short amount of time. Thus the rigors of active problem solving may become an issue for novices. Once learners gain expertise the scaffolding inherent in problem-based learning helps learners avoid these issues. These studies have however been conducted largely based on individual problem solving of well-defined problems.
Sweller (1988) proposed cognitive load theory to explain how novices react to problem solving during the early stages of learning. Sweller, et al. suggests a worked example early, and then a gradual introduction of problems to be solved. They propose other forms of learning early in the learning process (worked example, goal free problems, etc.); to later be replaced by completions problems, with the eventual goal of solving problems on their own (Sweller, Van Merriënboer, & Paas, 1998). This problem based learning becomes very useful later in the learning process.
Many forms of scaffolding have been implemented in problem based learning to reduce the cognitive load of learners. These are most useful to fade guidance during problem solving. As an example, consider the fading effect helps learners to slowly transit from studying examples to solving problems. In this case backwards fading was found to be quite effective.
Cognitive effects of problem-based learning
The acquisition and structuring of knowledge in PBL is thought to work through the following cognitive effects (Schmidt, 1993):
- initial analysis of the problem and activation of prior knowledge through small-group discussion
- elaboration on prior knowledge and active processing of new information
- restructuring of knowledge, construction of a semantic network
- social knowledge construction
- learning in contex
- stimulation of curiosity related to presentation of a relevant problem
Other outcomes of problem-based learning
One of the aims of PBL is the development of self-directed learning (SDL) skills. In Loyens, Magda & Rikers’ discussion (2008), SDL is defined as “a process in which individuals take the initiative…in diagnosing their learning needs, formulating goals, identifying human and material resources, choosing and implementing appropriate learning strategies, and evaluating learning outcomes.” By being invited into the learning process, students are also invited to take responsibility for their learning, which leads to and increase in self-directed learning skills. In Severiens and Schmidt’s study of 305 first year college students, they found that PBL and its focus on SDL led to motivation for students to maintain study pace, led to social and academic integration, encouraged development of cognitive skills, and fostered more study progress then students in a conventional learning setting (2009). PBL encourages learners to take a place in the academic world through inquiring and discovery that is central to problem-based learning.