Problem-Based Learning: What and How Do Students Learn?

Hmelo-Silver, C.E. 2004. Problem-Based Learning: What and How Do Students Learn?. Educational Psychology Review, Vol. 16, No. 3, 235-266.

"Problem-based approaches to learning have a long history of advocating experience-based education. Psychological research and theory suggests that by having students learn through the experience of solving problems, they can learn both content and thinking strategies. Problem-based learning (PBL) is an instructional method in which students learn through facilitated problem solving. In PBL, student learning centers on a complex problem that does not have a single correct answer. Students work in collaborative groups to identify what they need to learn in order to solve a problem. They engage in self-directed learning (SDL) and then apply their new knowledge to the problem and reflect on what they learned and the effectiveness of the strategies employed. The teacher acts to facilitate the learning process rather than to provide knowledge. The goals of PBL include helping students develop 1) flexible knowledge, 2) effective problem-solving skills, 3) SDL skills, 4) effective collaboration skills, and 5) intrinsic motivation. This article discusses the nature of learning in PBL and examines the empirical evidence supporting it. There is considerable research on the first 3 goals of PBL but little on the last 2. Moreover, minimal research has been conducted outside medical and gifted education. Understanding how these goals are achieved with less skilled learners is an important part of a research agenda for PBL. The evidence suggests that PBL is an instructional approach that offers the potential to help students develop flexible understanding and lifelong learning skills.“ Silver, p.235

Summary and Analysis

History Of Problem Based Learning

PBL (Problem Based Learning) is part of a history of approaches that stress the importance of meaningful, experiential learning.  In PBL students learn by solving problems and reflecting on their learning.  It has a dual emphasis on helping learners develop strategies and construct knowledge,

At the time of the article publication (2004) the author noted that a discussion of PBL was timely because of the flexible thinking, life long learning inherent in the approach.  Educators appreciate the approaches emphasis on active transferable learning."

PBL and Other Experiential Approaches

PBL is part of a family of approaches that includes Anchored Learning and Problem based Learning.

PBL is focused, experiential learning organized around the investigation, explanation, and resolution of meaningful problems (Barrows, 2000;

Torp and Sage, 2002).

Anchored Instruction uses a video based problem to introduce a challenge at the end.  The problem allows learners to apply their shared knowledge to a relevant problem; they also support ongoing problem comprehension because the solutions of ten require 15-20 steps.

In Problem Based Science, the problem is a driving question.  The problem is the focus for scientific inquiry and students must determine how they will answer their questions.

Two key issues that go to the heart of all three approaches are:

1.     The emphasis of learners actively constructing knowledge in collaborative groups.

2.  The transformation of student and teacher roles.  Teacher is a facilitator of collaborative learning rather than the main repository of knowledge.  Though the teacher may still do some direct instruction it is more in a more limited capacity and usually when such instruction is necessary to fill in necessary information relevant to the problem.

The author states that Self Directed learning (SDL) is a distinguishing feature of PBL, but I am unclear why/how SDL is not a characteristic of the other approaches as well.

Goals of PBL

1) construct an extensive and flexible knowledge base:

Constructing an extensive and flexible knowledge base involves going beyond accessing informational domains in isolation and requires integrating multiple domains.  "It is also flexibly conditionalized to the extent that it can be fluently retrieved and applied under varying and appropriate circumstances"(Bransford et al., 1990).  I interpret this to mean that the learner is conditioned to expect skills from different domains to be a part of any given problem - rather than a traditional approach where a domain is covered and then might rarely be used again.  Understanding, in this context, places knowledge of a domain in a toolbox that can be used frequently to assist in further problem solving.

2) develop effective problem-solving skills:

Developing effective problem-solving skills involves introducing problems that require the use of these skills.  This goal also requires the ability to apply appropriate metacognitive and reasoning strategies.  Metacognitive in this context refers to the learners ability to reflect on and create a problem solving plan, monitoring progress, and evaluating whether goals have been reached (Schoenfeld, 1985).

3) develop self-directed, lifelong learning skills:

Developing self-directed, lifelong learning skills is also related to metacognitive strategies.  Learner’s must be able to identify what they do and do not understand.  They must be able to set learning goals, and finally they must be a able to select appropriate learning strategies.

4) becoming effective collaborators:

Being a good collaborator means knowing how to function well as part of a team.    This includes establishing common ground, resolving discrepancies, taking mutually agreed upon action and coming to agreement.

5) becoming intrinsically motivated to learn

The final goal of becoming intrinsically motivate occurs when learners work on a task that is motivated by their own interests.  Providing problems that engage learners require that the problem designers understand what is developmentally appropriate for their students - challenging without being overwhelming. To be intrinsically motivating problems should provide students with "the proximal and tangible goal of applying their knowledge to solve a concrete problem" Silver p. 241.

The PBL Tutorial Process

The PBL learning cycle begins with the tutorial process.  The tutorial process begins with the presentation of a problem and ends with student reflection.  The PBL tutorial begins by presenting the learning group with a complex problem.  The problem requires the drop to collaborate together as well as question the facilitator as the go through a process leading to a solution.  The article describes a process where whiteboards are used.  The boards are broken into 4 columns, Ideas, Learning Issues, Action Plan.  The "Facts" section keeps track of information embedded in the problem.  "Ideas" serves to track the on going hypothesis about possible solutions to the problem.  "Learning Issues" tracks the issues which need further study or perhaps clarification from the facilitator.  The "Action Plan" column track of plans for resolving the issue.

The Role of The Problem

Some of the characteristics of well structured PBL problems are that they are:

• ·      ill structured
• ·      open ended
• ·      realistic and resonating for the learner
• ·      promote conjecture and argumentation
• ·      complex enough to require interrelated pieces
• ·      often require multidisciplinary solutions

The Role of the Facilitator

Good problems are a necessary but not sufficient conditions for effective PBL.  The teacher is an expert learner, able to model good learning strategies for learning and thinking, rather than an expert on the content alone.  The facilitator scaffolds through the use of effective questioning strategies.  Facilitation is a subtle skill involving knowing when and what questions are called for.

Collaborative Learning in PBL

Small problem solving groups are a key feature of PBL.  Small group structure may help distribute the cognitive load and may also widen the spectrum of expertise available to solve the problem.  Research also suggests that small group discussion enhance problem solving and higher order thinking.

Reflection in PBL

Reflection on the relationship between solving and learning in a integral component of PBL.  It is need to support the construction of extensive and flexible knowledge.  "Reflection helps students (a) relate their new knowledge to their prior understanding, (b) mindfully abstract knowledge, and(c) understand how their learning and problem-solving strategies might be reapplied. " Silver p. 248

What have we learned about PBL

This section provides a discussion of the evidence that PBL reaches its purported goals.  Much of the evidence came from medical schools and gifted educations institutions.

            Constructive Extensive and Flexible Knowledge

Med students scored slightly lower on more traditional, multiple choice based outcome measures but slightly higher clinical problem solving examinations.

            Developing Effective Problem Solving Skills

Med students from a PBL curriculum were more likely to provide hypothesis-driven reasoning than were students using a more traditional curriculum.  Hypothesis driven reasoning is a reasoning strategy taught by PBL and one indicator of effective problem solving skills is the ability or transfer reasoning strategies to new problems.  In my interpretation of these results, this does not show that traditional students were less able to develop effective problem solving skills.  If the indicator is that taught skills are more likely to be used again, they results would also need to show that traditional students had been taught a this approach, or another, but failed to used it in the context of a new problem.

            Developing SDL Skills

The research about developing SDL skills is focuses primarily on professional studies students.  And at the time the article was written (2004) opportunities for research for on wider groups was plentiful.  For students who are poor self regulators, PBL is likely to pose difficulties without appropriate scaffolding for students trying to develop SDL skills.  Becoming a self directed learner through the process of PBL is not a given.  How to structure PBL for less mature learners is still an open question.  Scaffolding is important for younger learning but research has also shown it to be necessary for adult learners.

            Becoming Effective Collaborators

There is not enough evidence to support the hypothesis that PBL helps students become better collaborators.  There is evidence that students work together to provide collaborative explanations.  There is also evidence that collaboration in tutorial groups plays an important role in motivation and student groups.  But there is also evidence that not all groups collaborate well.

            Becoming Intrinsically Motivated

There is little research that focused directly on this issue.   Most of the research has focused on student satisfaction and confidence.  The results of a PBL approach to statistical reasoning was mixed some enjoyed the class but other resisted changes to their ways of learning.  There is little empirical evidence about motivation in undergraduate and k-12 education.

My Questions  And Reflections: 

This article on PBL is similar in may ways to PBL as I have experienced it, but also differs in many ways and I wonder if there are multiple approaches using the same names.  For instance this example of a PBL problem form the article " when middle-school children were asked to build artificial lungs, they performed experiments to determine how much air the lungs had to displace (Hmelo et al., 2000). At several points during their problem solving, students typically pause to reflect on the

data they have collected so far, generate questions about those data, and hypothesize

about underlying causal mechanisms that might help explain the

data." is much different than the PBL mathematics problem solving approach  used at Exeter academy.

Even thought the PBL in this article is focused on larger problems than the ones I am currently tackling in my classroom, the section on the tutorial process, and the section on using the white boards in columns is something I can take back to my classroom.

Very intrigued by the section on the role of the facilitator, would like to find more literature about this.  Interesting both from and academic and professional growth perspective.

Much of the evidence about PBL in this article comes from medical schools or gifted education programs.  This is not the demographic I am working with and I wonder how effective the approach has been with other demographics and what research has been done to look at that.