1. Designing a Controlled Experiment

2. Observation: People use fertilizer on plants Question: Does fertilizer cause plants to grow faster? Hypothesis: I think fertilizer will cause plants to grow faster because…

3. Creating Groups
To do a controlled experiment make two groups that are the same but only test one
Control group
Not tested so you can compare to experimental group
**Demonstrates the normal standard
Experimental group Directly tested
Include the more groups the better idea

4. Multiple Samples
Five or more samples for each group returns better results
Experimental group x5
Control group x5
Include the more groups the better idea

5. Identifying Your Variables
Constant Variables are all of the things you keep the same for the two groups. Name the controlled variables:
Include the more groups the better idea 5

6. Identifying Your Variables
The Manipulated variable is what you change on purpose in your experiment. Its what you are testing. Ask yourself, what is different between the groups? ***Look for the one thing you do to the experimental group that you do not do to the control group
Include the more groups the better idea
What is the manipulated variable in this experiment?
The fertilizer 6

7. Identifying Your Variables
Responding variable is what you are looking for to change as a result of the manipulated variable
It could be something you observe or measure
Include the more groups the better idea
What would be the responding?
The height/growth of the plants 7

8. What are the 4 essential parts of a controlled experiment?
Control Group
Experimental Group
Manipulated Variable
Responding Variable
Include the more groups the better idea 8