Dependent Vs. Independent Variable

Read the Text

• Get Textbook and then with winter partner.• Read page independently page 639: Controlling

Variables• Person A & Person B shares what a variable is

(in your own words).• Person A shares what a manipulated variable

is (in your own words).• Person B shares what a responding variable

is (in your own words).• Both be ready to share with class.

Independent vs. Dependent

• The independent variable is the manipulated or responding variable?

The manipulated, because it is what you manipulate/change/control.

• The dependent variable is the manipulated or responding variable?

• The responded, because it depends on/responds to the independent/manipulated variable.

Example:

What is the effect of the amount of air in a rocket balloon on the time that rocket balloon moves?

What are we going to manipulate/change?• The amount of air in the balloon.What are we going to observe in response to the differing

amounts of air?• The time that the rocket moves.So the independent/manipulated variable is?• The amount of air in the balloon.The dependent/responding variable is?• The time that the rocket moves.

Let’s Try It!

Procedure.

1. Fill balloon with 2 pumps of air.

2. Let go of balloon in same direction and position.

3. Record the time the balloon is moving.

4. Repeat step 1-3 this time 4 pumps, then 6, then 8, then 10, then 12.

Data TableAmount of air (number of

pumps)Time rocket is moving

(seconds)

0 0

2

4

6

8

10

12

Graph

• Make a line graph.

• Independent variable data on the x axis.

• Dependent variable data on the y axis.

• Set the scale for the axes.

• Plot points.

Conclusion

• What is the final answer to the scientific question? Back up your answer with data.