PROBLEM BASED LEARNING (PBL)
Problem-based learning (PBL) is designed to "simultaneously develop both problem solving strategies and disciplinary knowledge bases and skills by placing students in the active role of problem-solvers confronted with an ill-structured problem that mirrors real-world problems. PBL models may be implemented using a variety of strategies but are generally characterized by the following steps: 1) the presentation of a problem to a small group of students, 2) discussion of the problem among the students which produces tentative explanations of the problem, and 3) an attempt to solve the problem.
Problem presentation involves presenting students with an ill-structured problem in which they can find personal relevance. Ill-structured or “messy” problems are defined as: a) more information than is initially available is needed to understand the problem, b) the problem definition changes as new information is added to the situation, c) many perspectives can be used to interpret information, and d) no absolutely "right" answer exists. Well-structured problems, problems most commonly presented to students in the school setting, provide students with all necessary information including the appropriate algorithm needed to arrive at a single correct answer. Student motivation to solve the problem revolves around finding the answer desired by the teacher. This is likely to lead to inert, unusable knowledge. When students work to solve ill-structured problems, they are working toward learning generalized procedures for problem solving that will transfer to new situations.
To get started using PBL follow the model shown below after dividing the class into groups of three to five students each. All groups may be assigned the same problem or a variety of problems may be addressed at once, depending on the needs of the teacher.
Problem Solving Model
1. Read and analyze the problem scenario:
- Discuss the scenario with your team.
- Don’t be tempted to start thinking about potential solutions or to start looking for information.
2. List hypotheses, ideas, or hunches:
- Based on what you have read, what do you think will happen?
- List your ideas, hunches, or hypotheses.
3. List what you already know:
- Begin your list with the information contained in the scenario.
- Add knowledge shared by other group members.
- Record this information under the heading: “What do we know?”
4. List what is unknown:
- Prepare a list of questions your group thinks need to be answered to solve the problem.
- Record them under the heading: “What do we need to know?”
5. List what needs to be done:
- Develop a plan. List actions such as questioning an expert, getting online data, or visiting a library to find answers to the questions developed in Step four.
- Prioritize the questions you are going to seek answers to, then divide up the questions among your team.
6. Develop a problem statement:
- A problem statement is a one- or two-sentence idea that clearly identifies what your team is trying to solve, produce, respond to, test, or find out.
- Record your statement on the Student Activity Sheet.
7. Gather information:
- Record your information and resources.
- You and your team will gather, organize, analyze, and interpret information from multiple sources.
- Exchange ideas; think about solutions; weigh alternatives; and consider the pros and cons of potential courses of action.
8. Present findings:
- Prepare a report or presentation in which you and your group make recommendations, predictions, inferences, or other appropriate resolutions of the problem.
- Be prepared to support your positions. If appropriate, consider a multimedia presentation using images, graphics, or sound.
NOTE: The steps in this model may have to be completed several times. Steps two through six may be conducted concurrently (at the same time), as new information becomes available. As more information is gathered, the problem statement may be refined or altered.
NOTE: When using the PBL model, the teacher acts more as a coach in helping students investigate the problem.
Jigsaw is a cooperative learning technique that creates “experts” on a certain topic within a classroom. A group of four to six students is broken down into jigsaw roles so that each student learns one aspect of the learning situation. For example, each of the students studying the impact of deforestation in a group of four could be assigned to determine the impacts on the atmosphere, hydrosphere, lithosphere and biosphere. This collaborative inquiry method supports the flow of energy toward new levels of understanding as members "jigsaw.” Each person is responsible for learning a different part of the whole picture and in a sense creates positive interdependence, a key aspect of cooperative learning.
After assigning students to jigsaw groups with a sphere to study, form temporary "expert groups" by having one student from each jigsaw group join other students assigned to the same sphere. Give students in these expert groups time to discuss the main points of their segment and to rehearse the presentations they will make when they go back their jigsaw group.
Once rejoining the jigsaw group, students engaged in an Earth system science problem can then discuss the interactions between and among the sphere. Teachers might want to use this visual to enhance understanding of the process:
Earth System Diagram
Group Investigation is a pedagogy for engaging and guiding students' involvement in learning. Students become active learners shaping events in their classroom. By communicating freely and cooperating in planning and carrying out their topic of investigation, they can achieve more than they would as individuals. The final result of the group's work reflects each member's contribution, but it is intellectually richer than work done individually by the same students.
Follow these steps to implement Group Investigation:
1) Students are assigned or decide on the topic for investigation.
2) Students divide the investigation into smaller parts.
3) Each student is responsible for researching one of the subtopics.
4) Students come together as a group and share their information.
5) Students synthesize information to produce an end product.
6) Each group member participates in the class presentation.