The Power of PBL: Bringing Problem-Based Learning into Your Classroom

Session 2 - Notes

April 23, 2004 notes

Facilitator: Professor G. Watson

                 University of Delaware

                 E-mail: ghw@udel.edu

                 PBL Clearinghouse website: www.udel.edu/PBLC

                 George Watson’s website: www.udel.edu/~watson

Introduction to Problem-Based Learning

(George) My name is George Watson and I’m a physics professor and Associate Dean at the University of Delaware. I want to convince you that the things we have done at Delaware can be relevant to your teaching. Delaware is a public institution with about 17,000 students and part of our charter is to educate the students of Delaware.

Let’s start with Problem Based Learning (PBL).  What is it?  It’s an approach that was started at medical schools over 40 years ago.  It helps students learn how to learn, and it’s under the umbrella of co-operative learning.

(Slide) What is Problem-Based Learning (PBL)?

Ø       PBL is a learning approach that challenges students to “learn to learn,” working cooperatively in groups to seek solutions to real world problems. 

Ø       PBL prepares students to think critically and analytically, and to find and use appropriate learning resources.

(George) So PBL uses real world problems to motivate students to learn; it uses both critical thinking and analytical skills; and it’s an introduction to research—a first step to learning how to do research. 

(Slides) “The principle idea behind PBL is that the starting point for learning should be a problem, a query, or a puzzle that the learner wishes to solve.”

PBL: Experience It Yourself

(George) You don’t do as much lecturing with PBL, you don’t give lectures first--you start with a problem.  Here’s an example of how it works.  I need two volunteers to read a dialogue that’s already prepared – one person will be Kim and one person will be Pat.

(Slides) Stage 1: Not again already!

v      Kim: I can’t believe you are leaving again next week!  Weren’t you just on a trip three weeks back?

v      Pat: We talked about this months ago. I committed to this trip almost a year ago.

v      Kim: Weren’t you there just last October?

v      Pat: I was.  What’s that have to do with anything?

v      Kim: Haven’t you been following the news?  Things are different now.  Lots of things!

v      Pat: Like what?

v      Kim: You’re impossible!  You need to get your head out of your science journals and read the paper occasionally.

v      Pat: OK. OK.  Just tell me what’s bothering you?  I travel all the time.  What’s upsetting you about this trip?

(George) I’d like you to discuss in groups the following questions:

Questions for Stage 1:

1.      What is the problem?

2.      What things might be troubling Kim?

3.      What should Pat do next?

(Board—Attendees responses) What’s bothering Kim?—Question 2:

ü       Pat’s safety and security

ü       Pat is over-involved in his work

ü       Pat has different views than Kim

ü       Difference in priority

ü       Family neglect

ü       Different world views

ü       Lack of communication

ü       Evasive

ü       Mistrust

ü       Marital problems

ü       Kim’s workload might increase in Pat’s absence

(Attendee) We don’t know the relationship between Pat and Kim.

(George) I kept it vague intentionally so you could project on them whatever assumptions you want for their roles. 

(Slides) Stage 2: Some more details…

Pat Nostaw is traveling to Paris for an international education conference.  Following several days at the conference, he is traveling to Beirut to visit a university there.  After that he is heading home to New York City.

7. What things might be troubling Kim?  Refine the list of things identified in Stage One.
8. What does Pat need to know to assure Kim about his travel plans?
9. What should we ask Kim about Pat to determine if her concerns are legitimate?

(George) Now looking again at our list, do we need to add anything or is there anything we should take out?  Let’s add:

ü       Pat is too interested in travel

(George) This scenario was based on my going to Singapore just after the SARS epidemic broke out, and I also was going to be visiting the National Islamic University in Southeast Asia.  What should my strategy be-- What should we ask Kim about Pat to determine if her concerns are legitimate?

(Attendees)

• How cautious is Kim?
• Is there a history of travel problems?
• Is he careless?
• Does he listen to the news when he travels?
• Do you trust him?
• Can he bring her along on the trip?
• Is she an academic?

(Slide) Stage 3: A twist at the end.

Pat’s friends Amal and Saouma are planning a first-time trip from Beirut to New York City in December to complete the final project report.

9. How does the list of ‘troubling things’ change for this different destination?
10. What are the top three worries your spouse or loved one would have about this trip?

What are the top three worries you would have about this new trip?

(Attendees)

·         Being arrested at the destination

·         Being hassled at the airport

·         Visa might not be honored / denied entry at NY

·         Responsibilities at home need to be addressed

·         Missing each other

·         Expenses

·         Cold weather in December

·         Discrimination

·         Personal safety

(George) This problem was meant to familiarize you with the way PBL is used in the classroom. 

(Slide) “…careful inspection of methods which are permanently successful in formal education…will reveal that they depend for their efficiency upon the fact that they go back to the type of situation which causes reflection out of school in ordinary life. They give pupils something to do, not something to learn; and if the doing is of such a nature as to demand thinking, or the intentional noting of connections; learning naturally results.”   John Dewey (1916)

(Slide) What are the Common Features of PBL?

Ø       Learning is initiated by a problem.

Ø       Problems are based on complex, real-world situations.

Ø       All information needed to solve problem is not initially given.

Ø       Students identify, find, and use appropriate resources.

Ø       Students work in permanent groups.

(George) Investigation is a big part of PBL.  Also, the aspect of working together is a big part.

 (Slide) PBL:  The Process

Ø       Students are presented with a problem.  They organize ideas and previous knowledge.

Ø       Students pose questions, defining what they know and do not know.

Ø       Assign responsibility for questions, discuss resources.

Ø       Reconvene, explore newly learned information, refine questions.

(George) Finding out what the students don’t know and beginning to figure out the questions that need to be asked, is a critical skill that PBL develops.  We ask students to write down the “learning issues”—the things that they don’t know.  They might assign the learning issues to be answered individually and then come back and meet as a group on it, and this may again start the process of questioning and finding new learning issues. 

(Slide) Problem Based Learning Cycle:

Ø       Problem, Project or Assignment

Ø       Group Discussion

Ø       Research      

Ø       Group Discussion

Ø       Preparation of Group Product

Ø       Whole Class Discussion

Ø       Mini-Lecture (only if needed)

Ø       Overview/Assessment

(George) At any point in the cycle, I can have a whole class discussion so that all the groups can find out what the smaller groups have found out.  I also have a safety net of using a lecture whenever I feel it might be needed.  And at the end of the PBL, you might give an overview or assessment of the project.

(Attendee) How can you be objective or evaluate what the groups have done?

(George)We typically create a rubric—this is one way to evaluate group projects.  You can create a matrix with criteria in mind that you want to evaluate.  Put some thought into what makes a good product.  When we develop a rubric, we share it with the students so they know what we are looking for when we do assessment.  In PBL, we focus less on the right answer and more on the process, so we need a tool like a rubric to help us assess students.  Also, most of us have some traditional assessment like an exam, where individual students are each responsible for the grade.

(Attendee) What is the maximum class size to use the PBL method?

(George) 240! We used it in a class of 240 students.  It’s limited when you have this large a class, buy they had extra help for the logistical elements—graduate students and others to help facilitate—but it worked. As a lone facilitator, I’ve had classes of around 36 people with groups of four to five people. 

(Attendee) What about time concerns? 

(George) One thing you must think about is how often can a group meet outside of class? Are you going to do the group-work in class? How long will the problem be?  I use shorter problems with intro students.  I give the problem at the last part of class, and the groups have two days to work on it.  Are you in a residential college where students all live near each other, or are they all over the city?  Do you have adults meeting at night that have families and limited time? Also, the physical arrangement of furniture—you might have to adjust the group meetings based on your own realities.

(Attendee) Do you need to have an activity first so that the students get to know each other and form groups?

(George) We usually assign groups as teachers.

(Attendee) Don’t the students resist? What if they are unhappy, can they change groups?

(George) I tell students that after they graduate, they don’t get to choose who they work with.

(Attendee) What if all the stronger students form a group, leaving the weaker ones behind?

(George) I used to put a strong math student with a weak student, but then I found that the talented student did most of the work.  I’m tempted to put all the strong students together and the weak ones together and see what happens

(Attendee) If the whole curriculum is based on PBL, then the students have to believe in it.  Doesn’t it work better if all classes are PBL?

(George) We don’t have across the board PBL at Delaware.  But students say they are working harder in PBL classes.  They’re not cramming it all in at the end before the exam.  PBL makes sure everyone is engaged in learning.  I’m not advocating all teaching be done with PBL.  It would be logistical nightmare to teach solely with PBL.

(Attendee) How often do you give the lecture format vs. PBL?

(George) Most of us are doing both, and sometimes we do PBL in the discussion section of a class or the lab section and keep the lecture format for the larger group. Or we might ask teachers to identify the parts of their class that aren’t working and try to convert that section to the PBL format.  You can just drop it into a class and see if it works.

(Attendee) What’s the ideal group size?

(George) Four to five people in a group.  We have improved attendance when there is a motivating group. If your groups are too large, you might find that the groups break down.  Each person might not feel as much responsibility towards the group.

(Attendee) Is there enough material available to use the PBL method?

(George) The textbooks you are currently using can still be the main resource for the students.  It’s often the tool used for investigation.  PBL has less structure, so there is not as much material specifically made for it.  You can also take case studies and turn them into PBL.  The reading can come after the problem is introduced—it prepares them to do the reading.  They don’t need to do the reading first. We are trying to get away from the first exposure to material being when you tell them about.  That’s why we want to introduce a problem first.

(Attendee) Will the nature of the course and material affect whether or not PBL will work?

(George) PBL came from medical schools first, and now there are two camps on PBL: one being the “authentic” camp where students work on problems that they will work on or encounter when they graduate.  That works when students will be practitioners of what they are learning—when the courses are oriented to the professions.  There is a more natural progression to PBL for these classes.  But that doesn’t work so well when you have something like physics courses for nursing students.  We try to find a way to make physics relevant for them. 

(Attendee) Is it better to provide information in a very easy format, and then do a case study instead of introducing the problem first?

(George) Sometimes it’s hard to see if the students get more out of a case study than a PBL.  Case studies accomplish a lot of what PBL does—the difference is we supplant some of the lecturing in PBL.

(Attendee) Some less assertive but good students don’t participate in groups while some dominant but incorrectly informed students might dominate the groups. 

(George) We assign roles so that the more dominant students don’t have a chance to always take over.  We have a “fact checker” whose role is to be a check on the dominant students, and question all the assumptions.  This ensures that the group can be working towards finding the correct information.

(Attendee) When does PBL not work?

(George) When the professor doesn’t believe in it.  Also in a class like studio art where the important thing is to hone individual skills.  And the more abstract the concepts--the less real world related—the harder it is to apply PBL.

(Attendee) Do you have permanent groups during the semester or for just one problem?

(George) Our recommendation is to use one group for the entire course.

(Attendee) Why?

(George) We find that students work well together if the groups last longer.  Plus, they make contracts and groundrules as a group.  We invest some time in the beginning of the semester which makes the groups last longer.

(Attendee) Doesn’t that negate the variety of feedback they’ll be getting?

(George) Yes, to some degree.  You have to decide what works best for you.  We have engineering classes that change groups with each problem as that’s what the profession is like as well.  Personally, I don’t want to deal with the interpersonal problems from the group coming up all the time. I’d rather they take the time in the beginning of the semester to think about working together.

Here’s a slide of a typical classroom at Delaware.  This shows about 60 students and 14 tables with the students working in groups.  Think about the role of the instructor in guiding students in a PBL classroom, now that we are not lecturing.  Discuss with your group what the instructor’s role is.

(Board) Role of the instructor:

ü       Assimilate and synthesize product of the group

ü       Set objectives

ü       Evaluate outcomes and product

ü       Monitor performance

ü       Moderator / serve as reference point

ü       Identify problem/project that are both relevant and interesting to students and valuable

ü       Facilitator

ü       Assign group formation

ü       Keep students on track / make sure they find the issues and objectives set out

ü       Periodic assessment

ü       Rules for teamwork

ü       Identify resources for research

ü       Be well informed on the problem

ü       Content expert

ü       Ensure availability

ü       Reflect on learning

ü       Involve students in the process

(George) You lose some control and you allow students to go off into areas that you might not have experience with. This is good—now we as professors can learn things too. It can be intimidating to the new professor though.

(Attendee) What qualities does the PBL teacher need?

(George) Risk taking ability—and not being intimidated if students know something more than you do.  You have to be comfortable teaching this way.  Students will go into areas that you can’t anticipate.

(Attendee) How many resources do you provide for a PBL?  How much do you give them?

(George) It depends on what you value.  You can give handouts if you don’t want to release the class to go to the library, etc… If what you want is for them to use the library or internet to learn to do research, then you would give that type of assignment.  You might direct them to a website.

(Attendee) How easy is it to assess performance?

(George) It’s not easy to assess what the individual learned in a group project; the assessment of what they learned is usually done individually.  I also look for how much students contribute to class discussion, how much reading they have done, how well do they know the information and share it with peers.  In-class participation can be identified, and you can evaluate people at every session.  It’s not easy but it can be done.  It’s subjective, but all assessment is subjective.

(Attendee) What if different groups go in different directions?  How much should we control the process?

(George) That’s a risk—a group might go in the wrong direction, or even the whole class. You can redefine the problem for the next time you use it.  You can hand off tangible things when groups reveal the learning issues but before they do the research so you nip it before it goes too far in the wrong direction.  If you hear class discussions that seem off as a whole class, you can redefine the problem.  Some classes have embedded in the group an experienced student—in medical school, there is a facilitator in each group.  I caution you from going over the learning objectives in class each time because the students will stop working on the issues and wait for you to go over them in class discussion.

(Attendee) I involve students in the structuring of the problem and ask them how they learn best.

(Attendee) Do you have a PBL curriculum?

(George) PBL is an option at Delaware.

(Attendee) Do you need to change assessment strategies?

(George) Students will work with you if they see the benefit of it.  But if you continue to use the same traditional, small fact, specific information exam, they won’t see the connection between the work they did and the assessment.  So yes, sometimes you have to change assessment strategies.

(Break)

(George) Why do we use PBL? Has it demonstrated itself as a better way to learn material?  We looked at MCAT scores where science knowledge is determined, and the content knowledge is the same when using either the traditional lecture or the PBL approach.  It’s not the real benefit.  The benefits are highlighted by the skills gained that are needed as defined by what characteristics are needed by college graduates.  When we asked business and employers what they wanted from college graduates, this is what they told us:

(Slide) Characteristics Needed in College Graduates

Ø       High level communication skills

Ø       Ability to define problems, gather and evaluate information, develop solutions

Ø       Team skills—ability to work with others

Ø       Ability to use all of the above to address problems in a complex, real-world setting

(George) Where do students develop these skills?  All of these skills are increased with the PBL method, in addition to gaining content knowledge.  The Carnegie Foundation chastised research universities for ignoring undergraduate students.  They gave ten recommendations, five of which are addressed with PBL.

(Slide) Recommendations from the Carnegie Foundation

Ø       Make research based learning the standard

Ø       Build inquiry based learning throughout the four years

Ø       Link communication skills and course work

Ø       Use information technology effectively

Ø       Cultivate a sense of community

(George) Their recommendations were not to reserve research for the last years and best students, but to start it earlier.  Also to cultivate a sense of community—my college experience was not about socializing within intellectual material.  PBL allows students to interact with each other and have discussions on the material.

At the American Institute of Physics, we asked employers what skills they wanted from physics graduates.  Interestingly enough, you’ll see that actual knowledge of physics is ranked low, while problem solving skills are ranked the highest.

(Slide) Skills Used Frequently by Physics Bachelors in Selected Employment Sectors, 1994

(George) Now I’d like for you to discuss the following question in your groups:

The principal idea behind PBL is?

4. PBL challenges students to learn to learn.
5. Learning is initiated by a problem.
6. Student-centered work in permanent groups.

(George) The correct answer is B.  I want to reinforce that what makes something PBL is that the problem comes first.

(Attendee) The answer A is what you want to achieve, and there are other ways to do this, but B is specific to PBL.

“The principal idea behind PBL is that the starting point for learning should be a problem, a query, or a puzzle that the learner wishes to solve.”        Boud (1985)

(Attendee) What about the need-to-know method?

(George) You are generating a need-to-know with PBL.  You are trying to stimulate the need-to-know situation, which is when people learn best.

(Attendee) If you are limited to what you need to know, sometimes there are things that you need to know but haven’t learned in a need-to-know format. 

(Attendee) Do we need to continually change the problem so that there are new problems each semester?  Can they find out from other students what the answers to PBL problems are?  It’s a lot of work to create a new problem.

(George) The process of doing work is not easily transferable.  The process of students finding answers for themselves is part of what they are learning in PBL. 

What are the barriers to using PBL?  Discuss this in your groups.

(Board) Barriers to PBL:

ü       Time consuming/workload

ü       Time vs. content

ü       Involving passive students

ü       Concept of PBL is alien to students

ü       Develop the skills to design PBL/ Professor’s skills in developing and using PBL

ü       Perception of usefulness

ü       Adequate resources: room set-up, computers

ü       Evaluating and assessing students

ü       Classroom structure

ü       Relationship to other classes

ü       Multiple section courses—students sign up for the easiest class

ü       Student culture—grade motivated

ü       Competition among students

ü       Reward system

ü       Content coverage

ü       Culture of the faculty

(George) The two main barriers at Delaware typically are:

1. The professor is not comfortable doing group work
2. Where’s the material for PBL?

You are going to have to invest time to make the PBL problem.  What’s relevant to the students varies from country to country and region to region.  There are geographic and cultural differences. You will probably have to make modifications to existing problems that area available but don’t quite meet your needs.  It’s easier if you have a department that wants to develop a PBL together.  Reflect back to when you were an assistant professor and you spent a lot of time preparing for a course.  Converting to PBL is the same time investment.  It’s like teaching a course for the first time.  But you can do it gradually, one problem at a time—try it in one course and see what happens. 

(Attendee) Is it more appropriate for some types of learners?  Should it be part of a mix of approaches?

(George) This format doesn’t work for everyone.  I think it’s best if used as part of a mix of methods.  A whole class of PBL is very intense.  It’s very active learning.  It’s best to mix in some lecture sessions.

(Attendee)Can you do this with co-teaching?  It seems like it would be easier to do PBL this way.

(George) Yes, especially if you have like-minded faculty, this work very well.  Now let’s go over the list of barriers:

• Classroom structure: at Delaware we gradually transformed the classrooms as more rooms were needed due to demand.
• Workload of professor: there is time needed to develop a PBL problem.  But there is also a time savings—there will be fewer papers to grade and once a problem has been used, you can use it again.
• Time vs. content: Where you can go wrong is to do all the traditional stuff and then add PBL on top of it.  You won’t have enough time.  You and your students probably still feel that if it’s not covered in class, students are not responsible for it.  We are trying to move content coverage out of lecture time.  You’ve moved it to the students outside of the classroom.  If you feel you have to mention things in the class lecture, you’re not going to be comfortable.
• Involving the passive student: About ten percent of the students still prefer traditional methods.  Also, if you have a lot of students just trying to get through—a class of low achievers—they won’t like it.
• Alien to students: In Delaware, there are some group experiences in high school, but it was usually a bad group experience.  If they are integrated well into a group experience, this barrier goes away. 

Here’s a sample of a PBL problem that we use at Delaware—you can find it at the website: www.udel.edu/PBLC.   This site has over 70 PBL problems that you can use.  This problem is a physics problem in four parts. In stage one, we define the learning issues.  The problem here is to determine who is at fault in this traffic accident.  We ask authors of the PBL problems to define the learning objectives, resources, to provide teaching notes, and assessment strategies.  This problem takes three days for students to solve.  A good problem is from the world of the students.  What excites you may not excite students.

(Slide) Good PBL Problems…

Ø       Relate to real world, motivate students

Ø       Require decision-making or judgments

Ø       Are multi-page, multi-stage

Ø       Are designed for group-solving

Ø       Pose open-ended initial questions that encourage discussion

(Attendee) When they are using a multi-stage problem, what if they make a wrong move at the first stage?

(George) You have to make sure it’s correct in the beginning.  Again, you can listen to group discussions, hold a whole class discussion, or even do a lecture if everyone is off to the wrong start.

(Attendee) Can you clarify what is designed for group solving vs. individual solving?

(George) The problem might require several perspectives, IE: an environmental view, a religious view—it’s based on the complexity of the problem.  Group problems can also involve brainstorming, where a group provides more ideas than an individual can come up with alone.

(Attendee) Of course a good problem would involve a content objective.

(Slide) Sources and Strategies for Writing Problems

Ø       Newspaper articles, news events

Ø       Popular press in the discipline

Ø       Make up a story – based on content objectives

Ø       Adapt a case [study] to a problem

Ø       Research papers

Ø       Other?

(Slide)Rubric to Evaluate PBL Problems

Other possible rubrics:

Problem Delivery and Process

Associated Assignments

Student Products and Presentations

(George) Realism is the most important factor when creating a good PBL.  Remember that we are trying to motivate students to learn about the topic.  So engagement is important.  Also, complexity, if it’s a problem that can be solved by an individual, it’s probably not a good PBL problem.  Let’s talk about the PBL Clearinghouse.  You can find this site at: www.udel.edu/PBLC.

(Slide) PBL Clearinghouse:

Ø       An online database of PBL articles and problems.

Ø       All material is peer-reviewed by PBL practitioners for content and pedagogy.

Ø       All problems are supported by learning objectives and resources, teaching and assessment notes.

Ø       Holdings are searchable by author, discipline, keywords, or full text.

Ø       Fully electronic submission, review, and publication cycle.

Ø       Controlled access by free user subscription, students excluded.

(George) It’s a free service; all you have to do is register. (We don’t want to make it available to students!) You can list your problem and also find out how many times your PBL problem was hit/cited.  You can put this on your teaching portfolio.  The PBL’s are reviewed just like articles.  We want to make sure that only PBL’s that have been used and field tested are on the site, that’s why we ask for a lot of supplemental material. 

(Slide) PBL Clearinghouse:

Ø       Currently there are more than 5000 registered users and 70 PBL problems.

Ø       Of the problems available, more than half are in physics, chemistry, and biology, but the number in other disciplines is growing steadily.

Ø       We are very interested in publishing adaptations of problems to other cultural/geographical contexts.

(Attendee) There are publishers that now have a number of books that allow you to choose certain chapters to compile for your own textbook.  Would you see using this for PBL?

(George) We’re beginning to see more curriculum material becoming available.  There are more than 5,000 people registered as PBL users on our website.  More than half of our problems are on physics, chemistry and biology.  There are also a number of accounting problems.  If you want to publish a PBL, please send it to us.  Here are some sites for you to use:

PBL at UD:www.udel.edu/pbl

PBL Clearinghouse:www.udel.edu/pblc

Watson homepage:www.physics.udel.edu/~watson

This workshop:www.udel.edu/pbl/AUB

If we had more time, we would have created a PBL for your courses; we don’t have enough time to do this.  Right now, I’d like you to imagine that you are in my class, Physics for Poets.  Please discuss and identify five fatal flaws that I committed in this new class.  (George now reads his course introduction) Note that this is what you shouldn’t do!

(Attendees)

·               You spoke clearly—that was all that we saw that you did right!

·               Competitive grading

·               Generally negative

·               Not ready/not prepared

·               Don’t let students know that this is a big experiment

·               Don’t want students to know that failure is an option

·               Didn’t talk about the course or physics

·               You were bored

(George) Tell the students that you are doing PBL and why.  But don’t reveal that it’s a big experiment.  I never talked about why I’m doing this or the benefits, I didn’t meet my own deadlines, so the students won’t honor them either. 

Now I’m going to open the floor for questions. What’s on your mind?

(Attendee)  My students don’t know why they are studying what they are studying, and don’t see how it fits into their professional lives, and don’t know what they are going to learn.  I think this should be an aspect of designing these problems. 

(George) That’s especially true in general education.  Students don’t understand the relevance of it. 

(Attendee)  Is Delaware using PBL throughout the university?

(George) There are so many different itineraries that we are formally trying to change at Delware.  So PBL is done by professors and wherever people want to change the way they teach.  We do faculty development on our campus, and a lot of professors come to our campus to learn about PBL and do the training.  It’s on the individual level at Delaware.  We are also trying to develop more PBL materials.

(Attendee)  In English language classes, sometimes the students fall back on Arabic in discussion even though textbooks are in English, and part of our goal is English proficiency.  I don’t want to encourage discussion in Arabic. 

(Attendee)  Put an English speaking person in each group, or have all report back in English.

(George) It can also depend on the rubric you create.  You can use English as the preferred language as part of the assessment included in the rubric.  Also, note that the internet has lots of information that’s in English, so that works well in giving exposure to many subjects in English.

(Attendee)  Do people usually do a written report?

(George) We do that or an individual oral presentation or group presentation.  But the report can be in any form, including things like floor plans, or any variety of things.

(Attendee)  Does PBL work well in a laboratory section?

(George) Yes, that’s where I started my PBL work.  I changed my thinking from working in pairs to working in groups of four or five.  We’re out of time. 

(End of Session 2)