1. Designing a fair experiment
Variables
Designing a fair experiment

2. What is a Variable?
The independent variable is purposefully changed by the scientist – “I” change!
The dependent variable is caused by and depends on the independent variable.
Controlled variables are values that a scientist wants to remain constant
Controlled variables are also known as constant variables

3. (What is kept the same)‏
More Examples…
Stirring
Type of sugar
Amount of sugar that dissolves completely measured in grams
Temperature of water measured in degrees Celcius
Does heating a cup of water allow it to absorb more sugar?
The faucet
Water pressure
Amount of water flowing per minute measured in mL per minute
Water faucet opening
closed
half open
fully open
How much water flows through a faucet at different openings?
Controlled Variables
(What is kept the same)‏
Dependent Variable
(What is observed)‏
Independent Variable
(What is changed)‏
Question

4. What is a Variable?