1. Independent Variables
Think I, I, I…
What do I change in the experiment?
I change this variable.

2. Dependent Variables Think D, D, D…
What data do I collect from this experiment?
I do not have control over this variable.
This is typically what I measure…

3. Controlled Variables Think C, C, C…
These variables stay Constant throughout the experiment.
I Control these variables too!
Think C, C, C…

4. Practice #1
Imagine you are going to add fertilizer to plants to see if that changes their growth?
What is are the following?
Independent Variable
Dependent Variable
Controls

5. Identifying Variables
Hypothesis: If fertilizer is used on a plant, then the plant will grow bigger in size.
Independent Variable:
The amount of fertilizer used measured in grams.
Dependent Variable(s):
Growth of the plant (height)
Controlled Variables:
Same size pot for each plant
Same type of plant
Same type of soil
Same amount of water/light

6. Practice #2
Imagine you are going to check if temperature affects growth in plants. So you collect several seeds and place them in pots at different temperatures.
What is/are the following?
Independent Variable
Dependent Variable
Controls

7. Identifying Variables
Hypothesis: How will temperature effect how a plant will grow?
Independent Variable:
The temperature of the seeds.
Dependent Variable(s):
Growth of the plant (height)
Controlled Variables:
Same size pot for each plant
Same type of plant
Same type of soil
Same amount of water/light

8. A group of High School Students is being used to determine the effectiveness of SAT prep classes.
2 groups of 25 students each are monitored.
The first group is given a prep class before attempting the SAT.
The second group is not given the class.
Their scores are monitored and compared. Identify the IV, DV and controls…
Practice #3

9. Identifying Variables
Hypothesis: Will attending an SAT prep class increase SAT scores for high school students?
Independent Variable:
Who attends the SAT prep class.
Dependent Variable(s):
SAT Scores
Controlled Variables:
Same testing conditions
Same SAT form test
Same time to prepare
This condition is different because it has a “control group”. Why?