2. Parts of an Experiment Parts of an Experiment

3. Variables All of the factors that could be changed in an experiment Constants Independent Dependent

4. Independent Variable  The variable “you” choose to change or test.  Examples include: amount of water, sunlight or drop height.  The variable “you” choose to change or test.  Examples include: amount of water, sunlight or drop height.

5. Dependent Variable  The variable you are observing or measuring  This variable depends on the independent  Example: The height of the plant depends on other variables such as the amount of water or sunlight  The variable you are observing or measuring  This variable depends on the independent  Example: The height of the plant depends on other variables such as the amount of water or sunlight

6. Constants (Controls)  The variables that STAY THE SAME to help you compare your results

7. Example  You want to see different colored light bulbs affect the growth of bean plants. Write a hypothesis I predict plants grow taller in white light  You want to see different colored light bulbs affect the growth of bean plants. Write a hypothesis I predict plants grow taller in white light

8. What is the independent variable? Color of light

9. What is the dependent variable? Plant growth

10. What variable should be held consant? Water, soil, type of plant