Presentation on theme: "+ Facilitating Collaborative Knowledge-building in Problem-based Learning Cindy E. Hmelo-Silver Rutgers University."— Presentation transcript:
+ 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 objects Symbolic tools Help 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 others contributions
+ Knowledge Building (KB) Discourse geared towards collective improvement of ideas (Scardamalia & Bereiter, 2006) Characteristics of collaborative KB: Problems that arise from attempts to understand the world Goal of improving the coherence, quality, and utility of ideas To negotiate fit between own and other ideas, use differences to catalyze advancement Collective responsibility for advancing understanding Critical stance toward information sources
+ Knowledge Building: Responsibility for learning is shared Expertise is distributed Building on others ideas is the norm Requires participant structures that: Engage learners with knowledge problems Move beyond IRE discourse
+ Participant Structures to Support KB Symmetric student-teacher interactions encourage student agency (Tabak & Baumgartner, 2004) Teachers play critical role (Polman, 2004) Examples: Facilitating Communities of Learners (Engle & Conant, 2002) Tools can help encourage discussion of scientific ideas and principles (Cornelius & Herrenkohl, 2004)
+ Key Features of Problem-based Learning (PBL) Learning is situated in meaningful problems that are: Ill-structured Selected to afford coverage of curriculum Small, collaborative groups Students discuss alternative causal explanations Allow students to compare their ideas with others Facilitator provides support for learning Structured whiteboard
+ Goals of PBL Help students develop: Flexible knowledge Effective problem-solving skills Self-directed learning skills Effective collaboration skills Intrinsic motivation
+ 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
+ B12 comes back
+ 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 cant 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 ideas Jim: 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?
+ 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 the Megan: 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
+ 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 others ideas
+ Results: Explanation Construction
+ 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 Building on student discourse Building on student discourse Focusing attention Constrains space Pushing for explanation Makes knowledge public and open for discussion See limits of knowledge Revoicing (OConnor & Michaels, 1993 ) Revoicing Take an idea put out by student and make clear for other students Legitimates different students Make sure important idea dont get lost Move group along in process Map between symptoms and hypothesis Goal: Elaborate causal mechanism Generate/ evaluate hypotheses Goal: Help students focus their inquiry; Examine fit between hypotheses and accumulating evidence Summarizing Goal: Ensure joint representation of problem; Establish common ground Help students synthesize data Encourage construction of visual representation Goal: Construct integrated knowledge structure that ties mechanisms to observable effects (Hmelo-Silver & Barrows, 2006)
+ Discussion Facilitator plays important but subtle role in PBL to help improve groups 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 Moment Hmelo-Silver & Barrows, 2008