Lesson 1: Science Describes

Maureen Dooley, B.S.Ed.

Copyright 2004. Permission is granted for classroom use and for non-commercial educational purposes.

Subject __________________________

Anticipatory Set (focus) -The students will be given a handout to read as they enter the classroom. *The handout will explain: Science does not claim to explain the world - to say why it is the way it is. Science does its best to describe the world, in two senses: How the world is and how the world changes. The changes are usually the most interesting things. Science says if you see THIS happen, then THAT will happen next.

Purpose (objective) - The students will be able to describe the driven pendulum.

Input - The teacher will have one students read the handout to the class and explain what he/she feels it means and/or given an example of it to the class. The teacher will further explain that when an experiment fails to produce the expected result, we can expect that one of the unstated assumptions was violated. Chasing down the violation often leads to new ideas and new science. For example, if you see a hand flip a light switch up, you expect the light to turn on. You make the "reasonable" assumptions that up is on, that the power generators are working, and that the light bulb is fresh. In any experiment we need to stay alert for the true nature of the system that we are observing.

Modeling (show) - The teacher will show the students the driven pendulum, but will not explain how it works or go into any detail about the structure of the pendulum. The teacher will explain to the class that they are to stand in a circle around the pendulum and that they will write down a description of what they see.

Guided Practice - The teacher will tell the students to stand in the circle around the pendulum. The teacher will restate the procedure; the students are to write a description of what they see on a piece of paper. Remember and restate that they are not to explain it, but to describe it.

Independent Practice - The students spend about 10-15 minutes in a circle around the pendulum describing what they see. More or less time can be allotted as necessary. When the descriptions are completed the students should return to their seats.

Closure - (Tell or show me what you have learned) Call on the students to talk about what they wrote down about the pendulum.

(NOTES) Observations should have included:
The loudspeaker pulls up and drops down
The loudspeaker may make a sound.
The pendulum swings back and forth.
The period (round trip time) is about 2 seconds.
The speaker pulls up near the bottom of the swing and drops down near the top.
Different students will see the pendulum swing differently; forward and back, side to side, or something in between.

Teacher Comments: The fact that the pendulum does not behave like others suggests that an unspoken assumption has been violated. In this case, the speaker is replacing the energy that is removed by wind resistance.

Describing a sequence of events carefully can give the impression that we know the outcome of the events before they happen. That, in turn, can give the impression that we have explained the outcome. In fact, we have only described in detail the events leading up to the outcome.