Sunday, September 30, 2012

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.


Stacey Caillier said...


Wow! This is a detailed summary of the articles main points and strategies! I especially liked how to took the time to unpack each of the goals of PBL and how the authors were defining them.

I'm intrigued by several things you write about in your reflection and would love to know more about what you are thinking. For example, how does this approach differ from Exeter and what you are currently doing? Did you get any ideas for things you might want to try/tweak? And what about the facilitator role particularly struck you, and why?

I'm also glad that you noted the population this study was based on - that is an important thing to keep in mind when thinking through how to translate the findings to your own work. It's concerning to me that studies of problem-based learning often happen in gifted programs or actually in private schools like Exeter. I wonder if underlying this is the assumption that only "gifted" kids can do this work... it brings to mind one of the most disturbing quotes I often hear from visitors to our schools: "Well, this is great, but I couldn't do this with my kids." I disagree with this with every fiber of my being and am anxiously awaiting more studies of doing problem and project-based learning with all kids!

Kcapozzoli said...


This is really an impressive review of the work. I am excited that you are finding great articles and it seems like you are starting to get a focus in your research. I was struck by the demographic information as well and it got me wonder, especially after our school visit, how your research question might have something to do with the demographics at your school.

Bryan Harms said...

Thanks for the comment and questions Stacey, I think it's worthwhile for me to answer them here, so here goes:

Q. How does this approach differ from Exeter and what you are currently doing?
A. The approach to PBL as defined in this article is to tackle larger problems. A single problem, or set of related that might take a small group of collaborative learners several hour or more to solve. There is a specific collaboration model that breaks the process of engaging the problems into 4 interrelated processes: Identifying Facts, Tracking Ideas For Problem Solving, Identifying Skills that Need to be Acquired, and Developing a Plan of Action.
Some of these steps are a part of the exeter model and what I am doing in my classroom, but the are introduced as problem solving strategies rather than a formalized approach. Additionally the scope/breadth of each of the problems in one of my classrooms is usually mach narrower than the larger problems presented in the article. My kids are usually tackling 4-6 problems per class. Also, one facet of PBL as I have experienced is the idea that the content necessary to solve a problem should be partly or completely embedded in the problem itself or should be known as the result of solving a previous problem. This was not mentioned in the articles discussion of PBL.

Q. Did you get any ideas for things you might want to try/tweak?
I gave a question in class today that was simply, how much does my yearly work commit cost. In pairs I asked students to address the facts, specifically I asked them to come up with 5-7 factual questions that they would like to ask me to help them start figuring out the problem. This models the 'bigger' type of PBL problem in the article. An the questioning phase models the fact identification phase of PBL as described in the article. I am was so excited about it that I gave the same problem to my math block - a mix of 6ht 7th and 8th graders.

Q. And what about the facilitator role particularly struck you, and why?
I want to be the great facilitator. The one that sees what when my kids are on the verge of an understanding and can lead them to discoveries, who can ask the right questions and to know when to keep quiet. To see when frustration levels are getting too high and to know the difference between a good struggle and a bad one. To convey information with a smile or a frown. It's why I want to be a teacher, the conversations, the active listening, the strategy and the tactics. It is really difficult to do well and the challenge of it and the progress I've seen and the growth I still seek is what gets me excited about coming to work everyday.

Bryan Harms said...

Hi Katy,
Thanks for the comment! I think your right on with the demographics piece. The idea that collaboration and complex problem solving is beyond certain kids is, to me, no different than saying that mathematics or reading is beyond certain kids. Maybe its just beyond certain schools and certain teachers :-) . I don't know but I feel that teaching kids how to collaborate and solve problems that are not simple is one of the most important things we can teach our kids to do.

Bryan Harms said...

Stacey, the question I gave was "How much does my yearly commute to work cost?"

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