The CPU Project

CPU Pedagogy

      The CPU pedagogy represents a rethinking of the roles of teacher, students, and materials. Students in a CPU course are largely responsible for the introduction, development, and critical evaluation of ideas, models, and explanations in physics. They do this by interacting with each other in small groups, doing experiments, and making sense in a structured setting. The teacher takes the role of a guide and mentor, and the course materials provide substantial support and structure for student groups.
      Each CPU curriculum unit (such as Force and Motion) is divided into several cycles, each intended to support students' construction of a relevant model or component of a model (the
curriculum unit overviews describe these cycles in detail). In turn, every cycle has three phases: elicitation, development and application.
      The next three sections describe these three phases. The text also contains links to example activities (the same example activities linked at the top of this page). The elicitation section contains two links. One link explains the elicitation activity and uses video to demonstrate how students respond to the activity. The other link simply displays the published lesson.
      Although students mostly work in small groups of three or four, they also participate in whole class discussions during every cycle. Infrequently, students work alone.

Phase One: Elicitation

Each cycle begins with an elicitation activity that engages students in an extensive and robust whole class discussion centered around some interesting phenomenon. Students are usually asked to make predictions, explain their predictions based on prior knowledge, observe the outcome of the experiment, and then suggest ways of making sense of the outcome, which often surprises many students. At the end of the elicitation phase, learners share their ideas for making sense of the outcomes. Sometimes individual students will share their ideas with the class. At other times, small groups will present their ideas to the rest of the class. Students often write their ideas on whiteboards or butcher paper, providing both the presenters and their audience with visual representations of ideas.
      The purpose of this activity is not to judge which ideas suggested by the students are "correct", but instead to reveal the ideas that make sense to at least some students and to identify important issues. These ideas and issues can serve as focal points of further inquiry. The two photographs show examples of this idea sharing. The first picture comes from a content workshop hosted by the Delaware CPU team. The second photograph shows a student in a university class for future elementary teachers at San Diego State University.
Click here for an example of an elicitation activity conducted in a high school classroom. The example includes video segments of students responding to the elicitation activity. To see the same elicitation activity as it appears on the CPU Curriculum Units CD, click here.

Phase Two: Development

      In the development phase students work in small groups using computer-based activities. During this phase students test the elicitation ideas in a wide variety of experimental, hands-on contexts. They record their observations, ideas and explanations on the computer and use computer simulators to receive model-based feedback. This format supports scientific sense-making discussions which appear to be critical to developing robust understanding. The units are based on research in student understanding for a particular topic, and are designed so that the activities challenge common student ideas and support development of more powerful ideas.
      Special software helps students keep track of their evolving ideas in idea containers. As students go through the development phase, they modify some of their initial ideas, cast some aside as not being useful, and invent new ideas. At the end of this phase each group selects a set of ideas that the group believes will account for the phenomena encountered thus far.
      At the end of the development phase the instructor leads a whole class/workshop discussion in which the learners consolidate their development phase ideas, and come up with a set of evidence-supported class consensus ideas. These ideas tend to be closely aligned with target ideas for the cycle, except they are phrased in terms suggested by the class. At this point the instructor may introduce appropriate technical jargon, conventions, and formalism.
Click here for an example of a development activity.


What is crucial in the pedagogy is that the conceptual seeds of these formalized ideas are generated by the students themselves. Students should come to see that the powerful ideas in science are inventions of the human mind and not dictums from authority.


Phase Three: Application

      The purpose of the application phase is to provide students with myriad opportunities to see the fruitfulness (and perhaps limitations) of the class consensus ideas and practice applying the formalized ideas to new situations. In classrooms where quantitative problem-solving is an important goal, many quantitative activities are carried out in this phase. Click here for an example of an application activity from the same Current Electricity cycle as the other two example activities. In the Christmas Tree Lights application, students consider what happens when bulbs burn out in both series circuits and parallel circuits.

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