1. Variables Review

2. Experimental research is…
The manipulation and control of variables

3. Speaking of variables….

4. What are the three types of variables?
Independent variables
Dependent variables
Controlled variables
Also called constants

5. Independent variables are…
What is being tested
What is being changed
The difference between the groups
The ‘cause’ of a change

6. Dependent variables are…
What is observed
What is measured
The data
The ‘effect’ caused by the independent variable

7. Controlled variables are…
Things that could change, but don’t
Kept constant by the scientist
Allow for a fair test

8. So an experimental question has to indicate the variables
How the independent variable will AFFECT the dependent variable
What the EFFECT of the independent variable will be on the dependent variable

9. For example…
How does the temperature of ocean water affect the speed of a hurricane?
Independent variable
T of ocean water
Dependent variable
Speed of a hurricane