What is PBL? |
Problem-based Learning ("PBL") is a constructivist learning pedagogy that puts the student in an active role where they have responsibility for acquiring the knowledge necessary to succeed in a course. This is very different from a traditional lecture-based classroom where the student's role is passive, i.e. they "receive" the knowledge imparted by the teacher.
The typical PBL process involves laying out a Problem for the students to solve in groups. Rather than starting with a lecture that includes what the students need to know to solve the problem, PBL flips the learning process on its head and students are required to figure out what they need to know in order to solve the problem. The goal is to motivate learning rather than force-feed it. Student groups address the key PBL questions: What do we know, what do we need to know, and what do we need to do. |
What kind of courses and what grade level does PBL work for? |
Course Content: While PBL earned its stripes in Medical Schools, it is now used in a broad array of both graduate and undergraduate level courses; at a few schools of higher education, all classes use a PBL approach. The key is the creation of effective problems that embed the course learning objectives rather than the course content. See below for sample problems from an array of grade levels and courses.
ASCD on what PBL looks like at each educational level, from Kindergarten through Higher Ed Specific suggestions for K - 12 |
How do you structure effective problems? |
Effective problems are at the heart of PBL and, to a large extent, determine the success of the course. The problem must embed the learning objectives for the course module and be sufficiently entertaining to engage the students in a path of self-inquiry.
Purdue: 3C3R Model Middle School Examples Undergraduate & High School examples from Stanford University of Cincinnati: Sample Problems McMasters University: Sample Problems Sample Problems for Business Courses Using simulations for PBL problems |
How do you assess whether the students are learning enough? |
Despite the myriad benefits of PBL, assessment remains a challenge, particularly when the content is complex and/or highly technical. Summative assessments are insufficient to ensure that each student is mastering the requisite knowledge during the term of the course; formative assessments are critical in order to ensure continuous and progressive improvement throughout the course (Elizondo-Montemayor, 2004). I have found classroom response systems ("clickers") offer an ideal solution for ensuring continuous progress of both the class as a whole and of individual students. If you haven't tried clickers in your classroom yet, I highly recommend the books by my colleague, Derek Bruff at Vanderbilt's Center for Teaching, or Doug Duncan, an Astronomer and History Channel presenter from the University of Colorado at Boulder.
Research supports using the answers to clicker question for this inverted approach to learning where, “Microlectures are injected only occasionally and when immediate circumstances warrant.” (Beatty, Gerace, Leonard & Dufresne, 2006, p. 31). |
How do you make sure the groups are effective? |
There are an array of considerations in creating and maintaining effective groups in a PBL classroom. While not an exhaustive list, several critical issues are:
1. The size of the group There are two issues to consider in deciding on group size: the size that best facilitates the course learning objectives and the number of groups you can effectively moderate during the class session. I find groups of 4 are ideal. Groups of 3 seem to work best if the students have comparable competency levels. With groups of 5, the risk of a free-loader seems to rise. I have minimal experience with larger groups, but Jose Amador discourages the use of groups larger than 5 (Amador et al.,2006, p.34). For large classes and for lower level learners (e.g. introductory classes--which are often the largest classes), there is some support for groups of 6 or more (http://www.bized.co.uk/current/pbl/index.htm). If you have one or more TA's, you can manage a larger number of groups. It is critical to ensure that each group has time to report progress on the 3 PBL questions (What do we know, need to know, need to do) and to ensure each group has access during class to the teacher or a TA. The need for access and participation should factor into your decisions about group size. Resource for PBL in large classrooms 2. Who determines group membership The complexity of the course content may determine your ability to allow groups to self select. In courses with highly technical or complex content, it may be necessary to assign groups in a manner that allocates ability and familiarity with the content evenly across the groups. This is the approach I take in the analytical PBL courses I teach. (In other courses, I have allowed groups to self-select based on common interests.) I use surveys that I post prior to the first class to gather the information I need to assign students to groups. 3. Free-loaders & Group Dynamics Group work increases the likelihood that one or more students will attempt to free-load by relying upon the other students to do the majority of the work. While problematic and unfair in traditional course, it is suicide in a PBL assignment because the problem is the vehicle for learning acquisition, not merely for assessment. There are multiple strategies that can minimize the free-loader potential. The easiest may well be to use an effective approach for apportioning grades. I use anonymous surveys (I use SurveyMonkey, but Zoomerang and Blackboard are two other options) of all group members at the end of each graded problem. The simplest approach is to have each member of the group allocate 100 points among all group members, including themselves. I then use the results as "weights" that I apply to the grade assigned to that group's problem. Individuals who contribute less than their pro rata share will see their grade drop proportionately--and sometimes precipitously. 90% of a B is only a C; 75% of a B is an F. Each member of a relatively good group with one free-loader would all see a corresponding rise in their grade as the pay-off for doing the free-loader's work. Another approach is to ask a series of questions that evaluate research contributions, attendance at meetings outside of class, etc. The average result of the questions then becomes the weight applied to the group grade. Jose Amador (telephone conversation, June 29, 2009) takes the results of such questions one step further: group members whose composite grade falls below a certain level are evicted from the group and must work on the problems alone, a formidable challenge in a PBL classroom. The assignment of group roles (e.g. leader, moderator, researcher, etc) that rotate from problem to problem is another strategy for ensuring each group member carries their share of the workload or that, if not, the teacher can determine who the slackers are. http://www.uc.edu/pbl/student_groups_rules.shtml Group Dynamics Resources Resources: Oakley, etal. (2004). Turning student groups into effective teams. Retrieved from: http://tinyurl.com/2f3hkpm |
What does a PBL classroom look like? |
The PBL classroom is abuzz with conversation, web-surfing a,d group debate. Conversations continue long after class ends, however, which is a complaint of some students, i.e. PBL is more work for the teacher and the students.
The Internet is a highly useful medium for facilitating remote and virtual particiaption. I have had groups use Google docs, Wiki's, and the Blogs I create for each group in each class. You can see sample Syllabi, problem sets, assignments, and blog "conversations" and "report-outs" on the websites for some of my PBL classes: Undergraduate Graduate Additional Classroom-specific videos & examples: What to do--and not do-in a higher ed PBL classroom Video Games as a vehicle for using PBL Project Learning in a High School Science Class Video Clips of PBL in a Middle School Setting |
Can you use PBL in a large classroom? |
While PBL would appear to be most effective in smaller classrooms, it can also be an effective tool for large classes, assuming there are enough TAs to make sure each group receives enough support. It can also be an effective pedagogy for online courses that assign members to groups that meet virtually.
Using PBL in large classrooms |
Note: See Resources tab for references listed above.