Lesson
Procedure for Teaching Rule-relationships
Pressure Temperature
Rule–relationships are knowledge NOT of how one thing goes with another thing (facts), but of how one set of things goes with (is connected to) another set of things. Sometimes rule-relationships are called principles, or laws, or correlations. Rule-relationships are stated in several ways. For example,
1.When the demand for a product increases, the price increases.
2.Behavior that is reinforced will occur more often.
3.Democratic nations tend not to make war against other democratic nations.
4.The more members of a religious group share beliefs, the more members of the group feel protection by the group.
The sciences contain many rule-relationships. A course in physics, for example, is almost entirely about “laws,” such as laws of motion.
There are at least two ways to teach rule relationships.
1.State the rule-relationship and then present examples that back it up. This is the same as defining a concept (granite) and then presenting examples of granite. Deductive.
General[deduce/judge what is implied by general idea] Particular
2.Present examples of the rule-relationship and then help students to examine the examples, find the connection, and state the connection.
Inductive.
Particular [Induce/figure out what is common to particulars] General
Here’s an example. The question is, Is there a connection between how steep an inclined plane is and how long it takes a ball to roll down it?
[Please skim the text and watch the videos.]
You could TELL students the rule-relationship (the steeper the inclined plane, the less time it takes the ball to roll down the inclined plane) and then show examples using inclined planes of different angles. These examples would confirm the rule.
Or, you could have students do an experiment by rolling balls down inclined planes of different angles, measuring how long it takes each ball to roll down, and then draw a conclusion. The first way requires fewer skills. Students merely compare examples with the rule. “Yup, the ball takes less time when the angle is steeper.” This second way involves more skills than the first method. For example, student have to change the angles, measure the times, write the measurements, compare and contrast the instances, and figure out the connection. This means you would have to teach these pre-skills BEFORE students do the experiment. Here’s an example.
Procedure for Teaching Rule-relationships
Set up
A middle school science class is studying pressure. The teacher wants students to learn a rule-relationship that connects pressure and temperature, but even more importantly, the teacher wants students to learn HOW to figure out how things are connected.
The teacher reviews background knowledge (taught earlier) on molecules, gasses, and certain laws of kinetic molecular theory.
2.Objectives
Students are presented with examples of measurements of the pressure of gas in a closed cylinder and corresponding measurements of the temperature of the gas. Students compare and contrast each example and summarize them with a statement of the rule-relationship. “The greater the pressure (or when pressure increases), the higher the temperature (or temperature increases).”
5.Frame
Teacher.“Okay, now let’s see IF there is any connection between pressure and temperature.”
Focused Instruction.
Teacher. “I’m going to change the pressure of the gas in this enclosed cylinder. You will see the measurement on the screen. You will also see the corresponding temperature of the gas that goes with the pressure. You will record the measurements in a table, like this.”
[Teacher varies the pressure five times. Students record pressure and temperature.]
When Pressure IsTemperature Is
200 lbs/square inch120 degrees
150 lbs/square inch 100 degrees
170 lbs/square inch 110 degrees
230 lbs/square inch 150 degrees
80 lbs/square inch 90 degrees
Teacher.“Okay, boys and girls. Let’s arrange pressure from lower to higher. Which measure of pressure is lowest?”
Class.“80 pounds.”
Teacher.“Next?”
Class.“150 pounds.”
Teacher.“Next.”
Class.“170 pounds.”
Teacher.“Next.”
Class.“200 pounds.”
Teacher.“Next.”
Class.“230 pounds.”
Teacher.“Now rewrite the table with the lowest pressure on the bottom.”
When Pressure IsTemperature Is
230 lbs/square inch 150 degrees
200 lbs/square inch120 degrees
170 lbs/square inch 110 degrees
150 lbs/square inch 100 degrees
80 lbs/square inch 90 degrees
Teacher.“Start at 80 pounds. What’s the corresponding temperature?”
Class.“90 degrees.”
Teacher.“Yes, 90 degrees.”
Teacher.“Now, go up to 150 pounds of pressure. What happens to temperature?”
Class.“It goes up.”
Teacher.“Now look at the rest of the pressures, one at a time. What happens to the corresponding temperature?”
Class.“It goes up.”
Teacher.“So is there a relationship between pressure and temperature?”
Class.“Yes.”
Teacher.“State the relationship.”
Class.“When pressure increases, temperature increases.”
Closing.
The teacher reviews the data and the rule-relationship. The teacher also reviews the steps that the students followed to find the rule relationship.
1. Measurement of both variables.
2. Arrangement of the measurements in an order that would make change easy to see.
3. Comparison of one set of corresponding measures with another to see if and how a change in one variable was connected to a change in the other variable.