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Facilitating Collaborative Knowledge-building in Problem-based Learning

Cindy E. Hmelo-Silver Rutgers University

+Overview

Why Problem-based Learning?

Theoretical Framework

The Problem-based Learning Process

Knowledge building in a PBL tutorial

+Why Problem-based Learning?

We live in a complex and dynamic world

Need to go beyond learning facts Useable and flexible knowledge Soft skills (Derry & Fischer, 2007)

Preparation for lifelong learning, reasoning, and problem solving (Fischer & Sugimoto, 2006)

+Sociocultural framework

Learning is embedded in sociocultural context (Cole & Engeström, 1993)

Cultural artifacts help mediate thinking and interactions (Kozulin, 1998)Material objectsSymbolic toolsHelp organize and constrain activity

Learning occurs through discursive activity

+Discourse and Learning

Knowledge constructed through social interactions (Palincsar, 1998) Emphasis on discourse Student-centered Participant structures to support learning

conversations

Need to provide affordances for constructive processing (Chi et. al., 2002; Greeno, 1998) Collaborative explanations that build on other’s

contributions

+Knowledge Building:

Responsibility for learning is shared

Expertise is distributed

Building on other’s ideas is the norm

Requires participant structures that: Engage learners with knowledge problems Move beyond IRE discourse

+Key Features of Problem-based Learning (PBL)

+Goals of PBL

+PBL Tutorial cycle

+PBL outcomes

Research with professional students shows PBL students more likely than comparison to: Construct accurate and coherent explanations (Hmelo, 1998; Schmidt et al., 1996)) Use basic sciences as a tool for reasoning Construct better integrative essays despite lack of differences in factual knowledge

(Capon & Kuhn, 2004) Apply targeted concepts to transfer problems in computer-supported PBL (Derry et al.,

2006)

Positive effects with middle school children to learn about complex systems (Hmelo, Holton, & Kolodner, 2000)

Preservice teachers learned to apply ed psych concepts to new problems as concepts diffuse around class (Hmelo-Silver, 2000)

Recent meta-analysis shows that PBL superior to conventional instruction on knowledge application (Dochy et al., 2003) No differences on factual knowledge

+Knowledge Building in PBL(Hmelo-Silver & Barrows, 2008)

PBL tutorial process

Research questions: How is KB accomplished in PBL? How does facilitator support KB discourse? What characterizes interactions within the group?

Methodology: Participants

5 medical students, expert facilitator problem of pernicious anemia

Data sources: 5 hours of video over 2 group meetings Qualitative analysis Quantitative coding of discourse moves

+Context

The Case of Ann George 72 year old female Presents with 4-5 week history of numbness Additional signs and symptoms elicited from

PBLM Diagnosis is Vitamin B-12 deficiency caused

by pernicious anemia

+Getting Started

+Collaborative KB I: Beginning Understanding

Early rapid generation of hypotheses based on limited data and limited prior knowledge

Facilitator pushes students to explain; students realize their limits Helps keep important ideas on the table after Donna

proposes pernicious anemia is “a big one”

Facilitator: What, what's pernicious anemia?Donna: Uh, it's a deficient, deficiency of cobalamin.Megan: Vitamin B12, cobalamin or...Jim: Or folate.Megan: Or folate.Donna: Yeah, but it's not, that's not pernicious anemia. That's … another macrocytic anemia.Megan: Pernicious anemia is specifically.Jim: Oh. You're right. That's right.Donna: And um, you get anemia and you can also get eh, um, peripheral...Megan: Neuropathies.…Cheryl: Technically pernicious, pernicious anemia is technically just the loss, the lack of intrinsic factor.Donna: The loss of intrinsic factor. So you don't absorb…Megan: Right. That's a good distinction. You see, we just...Cheryl: As opposed to like somebody who had part of their intestine removed and can't absorb…Cheryl: We kind of lump it all together, right?Donna: Yeah…Megan: But it's tied in with vitamin B12.…Facilitator: So should we have pernicious anemia up as a hypothesis?

+Hypotheses and Learning Issues at end of Session 1

+Collaborative KB II: Moving Forward

Pernicious anemia crossed off hypothesis list at end of session 1

Initial critique of information sources in session 2

Pernicious anemia returns as students are reporting their self-directed learning as several students came across this as something in need of explaining

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B12 comes back

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Facilitator question: How are we on pernicious anemia?

Leads to long discussion of causal mechanisms with all group members contributing Ideas refined into causal explanation of how

and why B-12 can’t be absorbed

+Jim summarizes

“ Well, that, that's exactly it. Like 90 or 10% of the, of elderly that have a vita, vitamin B problem is due to pernicious anemia. The other 90% … is due to the fact that, that when you … ingest vitamin B12 it's complexed with a protein, an R protein. And they lack the ability to break that protein apart to have the vitamin B site of cobalamin free. So then it can bind to the intrinsic factor. So if they, it's not binding… if it's not breaking off, you may, you may have tons of intrinsic factor, but since it can't get a hold of it, it's like not gonna do.”

+Collaborative KB III: Integrating and Consolidating

The Drawing episode

Facilitator prompt led to 29 minute episode of extended KB of group constructing integrated and coherent model

+Starting the Discussion

Facilitator: Um, probably the best way to, to pull this all together I suppose is to… tell me what you think is involved in her nervous system. Can… you draw a diagram of where you think the problem is?”

+Beginning with comfortable ideasJim: We can start with intrinsic

factor and...

Megan: Yeah we can start with saying...

Jonathan: ...then getting more into the symptoms.

Megan: ...How do you get vita, vitamin B12 into the body? What is it used for?

Donna: So with, yeah.

Megan: And without it, what happens?

Donna: So with the actual patient, she lacks intrinsic factor, which is her primary problem…

+Mapping causes and effects

Connecting hypotheses about causal mechanisms (e.g., anatomy and physiology) to evidence (e.g. signs and symptoms When drawing switched from

representations of basic science processes to signs and symptoms or between levels of science, students engaged in causal talk

Facilitator prompt “Now you're going to bring it into the nervous system?”

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Moving from the mechanism to the patient

Jim: We, you start with … odd number of carbons for the fatty acids…Megan: And then you incorporate it a, a carbon dioxide that it's a carboxylation reaction for the propianol Co-A to the methylmalanil Co-A. … it's actually a mutase reaction for the methyl….Donna: You need a CO2.Megan: Yeah, and the next one actually is a, so you got it to a four chain with this, which is the methylmalinal Co-A. …Right….Jonathan: So these get incorporated into theMegan: Membranes…Jonathan: So incorporated into the membranes and then you get... neuron loss, demyelination.Jim: Specifically dorsal column. Yeah. Specifically dorsal column.Megan: Right.Jim: And it, it's called like the, the term, the category is a, is a metabolic demyelinization.Megan: And you get neuronal also um, various things that happen. I believe you get neuronal cell swelling within the membrane and then you can get neuronal death. And that's when you get the paralysis and once it progresses to that stage, as we know, neurons will regenerate.

+Wrapping Up

Representation made salient what was missing

Still needed to make connections to structural and functional abnormalities

Students noticed inconsistencies and that they had not really localized problem

Finished by working together to complete understanding of the anatomy

+Facilitating PBL

Discourse moves (small grain size)

Helping advance group (intermediate grain size)

Goals and strategies (really large grain size)

+ Results: Questions

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Short Long Meta Totals

Student

Facilitator

+ Explanations Coding

Level Simple Elaborated Causal Elaborated

Interaction New idea introduction Modification Agreement/ Disagreement Metacognitive

Results Facilitator makes few, no new ideas Students

many simple statements taken alone often construct causal explanations over many turns build on each other’s ideas

+Results: Explanation Construction

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200

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600

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New Ideas Modification Agreement Disgreement Metacognitive

Statement type

Fre

qu

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Students

Facilitator

+Maintaining the Discourse

Analysis at level of episodes (n=101)

Facilitator initiated 60% of episodes; students initiated 40%

Facilitator initiated, mean 49.9 turns

Student initiated 34.3 turns

Of facilitator initiations, 62% questions or statements related to monitoring or group dynamics

Of the student-initiated, 35% were meta statements or monitoring questions.

+Facilitation Strategies

+Discussion

Facilitator plays important but subtle role in PBL to help improve group’s collective understanding

Students and facilitator share responsibility for creating conceptual artifact

Facilitator and students adapted discourse moves over time Facilitator did more questioning in session 1 than session

2 Students generated most ideas in session 1, narrowed

and refined in session 2 Prompt for drawing episode occasion to negotiate rich,

coherent understanding

+Open Questions

Can some of these facilitation techniques be used to scaffold KB in other settings?

How can some of these techniques be offloaded onto cultural tools and participant structures?

How does facilitation need to be adapted to other settings?

+Final thoughts from Dr. Barrows

+ Facilitating PBL: Taking Advantage of the MomentHmelo-Silver & Barrows, 2008

+Facilitating: Focusing Attention

+Facilitating PBL: Revoicing