1. Experimental Variables
Notes and Practice

2. Experimental Variables:
Independent Variable (IV):
The variable purposely changed by the experimenter
Control:
One of the IV’s that is standard (normal)
Dependent Variable (DV):
The outcome of the experiment (what the experimenter is measuring)
Controlled Variables (Constants):
Variables that remain the same during the experiment

3. Practice #1
Question/Problem
Experimental Variables
What would my fuel efficiency (mpg) be if I filled my car tires with helium instead of air?
Procedures?
Independent Variable:
Control:
Dependent Variable:
Constants:

4. Practice #2
Question/Problem
Experimental Variables
What will my 1-mile running time be based on the amount of water I drink?
Procedures?
Independent Variable:
Control:
Dependent Variable:
Constants:

5. Practice #3
Question/Problem
Experimental Variables
How tall will a plant grow if I feed it MiracleGrow in addition to water?
Procedures?
Independent Variable:
Control:
Dependent Variable:
Constants:

6. Graphing

7. Graphing
T = Title
A = Axis
I = Interval
L = Labels (w/ units)

8. Axis D = Dependent Variable R = Responding Variable Y = Y-axis
M = Manipulated Variable
I = Independent Variable
X = X-axis

9. Type of Graph If IV is categorical = Bar Graph
If IV and DV are continuous = Scatter Plot
If change over time = Line Graph

10. Practice #1
What would my fuel efficiency (mpg) would be if I filled my car tires with helium instead of air?
Type of graph:
Type of Gas
Air
Helium
Nitrogen
Argon
Oxygen
Mpg
27.1
28.7
27.9
26.7
27.2

11. Practice #2
What will my 1-mile running time be based on the amount of water I drink?
Type of graph:
Volume of Water
0 L
0.5 L
1.0 L
1.5 L
2.0 L
Run Time (min.)
6:01
5:54
5:51
5:34
5:41

12. Practice #3
How tall will a plant grow if I feed it MiracleGrow compared to water?
Type of graph:
Plant Height
Days 1 3 5 7 9
Water
0.8 cm
1.1 cm
1.5cm
2.0 cm
2.3 cm
Miracle Grow
0.9 cm
1.3 cm
1.8 cm
2.4 cm
3.1 cm

13. Practice #1
What would my fuel efficiency (mpg) would be if I filled my car tires with helium instead of air?
Type of graph:
Type of Gas
Air
Helium
Nitrogen
Argon
Oxygen
Mpg
22.1
28.7
25.9
18.7
20.2

14. Practice #2
What will my 1-mile running time be based on the amount of water I drink?
Type of graph:
Volume of Water
0 L
0.3 L
0.7 L
1.4 L
1.6 L
2.0 L
2.2 L
2.4 L
Run Time (min.)
6:01
5:54
5:51
5:34
5:41
5:38
5:33
5:39

15. Practice #3
How tall will a plant grow if I feed it MiracleGrow compared to water?
Type of graph:
Plant Height
Days 1 3 5 7 9 11 13 15
Water
0.8 cm
1.1 cm
1.5 cm
2.0 cm
2.3 cm
2.7 cm
3.0 cm
3.2 cm
Miracle Grow
0.9 cm
1.3 cm
1.8 cm
2.4 cm
3.1 cm
3.5 cm
3.9 cm
4.6 cm