Jim Nelson

Learning Cycle Model of a Science Lesson

Editors note: One of the goals of AAPT is to provide support and encouragement to those new to teaching physics by sharing ideas that experienced physics teachers have found helpful. I hope you will look to this column throughout the year to find help with lesson planning, ideas for classroom management, and opportunities for professional growth. This months contributing authors, Jane and Jim Nelson, are award-winning physics teachers with years of experience in the classroom, conducting PTRA workshops, and serving as leaders for local, state, and national AAPT organizations. Their contributions to physics teaching are much too numerous to list here, but their joy in sharing ideas with you is typical of the support you will find from AAPT.

AAPT/PTRA--A Part of the Solution.

A train barrels directly toward a stone wall. It looks like a disaster is inevitable. Suddenly, a group of railroad workers run to a switch that changes the direction of the train. They reroute the train onto a new track by throwing the switch just in time. Perhaps you had not known what to do, nor were you strong enough to do it yourself, but you now see that it was not a forgone conclusion that the train had to run into the wall. In this scenario, the train represents precollege physics education in the United States. The wall represents the classroom situation that many teachers find when they are assigned to teach physics. These teachers often find themselves teaching a subject for which they were not adequately prepared. It is not their fault, but rather the result of the necessity of having a teacher assigned to the class. The United States needs students to be prepared for a future in which science and technology will be more and more a part of everyones life, and there are not enough well-prepare...

Buoyancy Can-Can.

In this paper, a discrepant event is used to initiate a learning cycle1 lesson to help students develop an understanding of the concept and equation for buoyant force. The data are gathered using readily available equipment and then graphically analyzed using a four-step analysis consistent with the modeling instructional approach.2 This laboratory activity is appropriate for high school or first-year college physics, and provides the opportunity for review of free-body diagrams, experimental design, and graphical analysis. We use the “BSCS 5E” version of the Karplus learning cycle idea, popularized by Bybee, in which students are expected to Engage, Explore, Explain, Elaborate, and Evaluate.3

Physics teaching resource agent program

As a result of the “Nation at Risk” report in 1983 and in response to the great concern for the state of high school science teaching, the leaders of the American Association of Physics Teachers began to think about having a program of professional growth led by high school teachers. A proposal for the “Development of Physics Teaching Resource Agents (PTRAs),” developed by Jack Wilson, Don Kirwan, and John Layman, and directed by Jim Nelson, was funded (1985-1989) by the National Science Foundation.

A New Look at an Old Activity: Resonance Tubes Used to Teach Resonance

There are several variations of resonance laboratory activities used to determine the speed of sound. This is not one of them. This activity uses the resonance tube idea to teach resonance, not to verify the speed of sound. Prior to this activity, the speed of sound has already been measured using computer sound-sensors and timing echoes produced in long tubes like carpet tubes. There are other methods to determine the speed of sound. Some methods are referenced at the end of this article. The students already know the speed of sound when they are confronted with data that contradict their prior knowledge. Here, the mystery is something the students solve with the help of a series of demonstrations by the instructor.

Quantity Versus Interval as a “Hinge” Concept

Column Editors note: It is extremely important for students to develop definitions of terms from shared experiences such as the ones described by the Nelsons. Conceptual development in students will be hindered if we assume that dictionary definitions are adequate for developing understanding or that the meanings students associate with physics terms are accurate. Careful attention to what we say is crucial but we must also incorporate time for student discourse into instructional planning. Discussion of these “hinge” concepts requires close attention to addressing the linguistic problems associated with developing scientific literacy.