1. Identifying Variables

2. Cornell Notes Create Cornell notes for the following PowerPoint.
Make sure you include questions and a summary
Include answers

3. Types of Variables There are 3 main types of variables:
Independent Variable (IV): The variable that is changed or manipulated by the scientist; the ‘I control’ variable
Dependent Variable (DV): The variable that might respond because of what the scientist changes – what is being measured
Control Variable(s) (CV): The variable(s) that will stay the same throughout the experiment

4. Remember! Your hypothesis can TELL you what your variables are!
Ex. If some students eat breakfast before school and others do not, then the ones who do eat breakfast will have better grades in their morning classes, because their brains have more energy to think.
IV: Eating breakfast
DV: Better grades in morning classes
CV: test given

5. Use this hypothesis to identify the variables:
Practice
Use this hypothesis to identify the variables:
1. If 7th graders and 8th graders complete the same math problems, then the 8th graders will have more answers correct, because they have studied math for one year longer than the 7th graders.
IV: ______________________
DV: ______________________
CV: ______________________

6. Now read the following experiment and identify the variables
2. Elizabeth wanted to test if temperature affected how fast milk goes bad and curdles. She left milk in a room temperature closet, a fridge, and a oven that was turned on low heat. She then measured how rotten the milk was after 10 days.
IV: ____________________________________
DV: ____________________________________
CV: ____________________________________

7. Hypothesis Writing

8. Form a Hypothesis
Hypothesis: an educated guess or prediction; an “if, then, because” statement
If ____independent (manipulated) variable_____
then__dependent (responding) variable_____
because ___what you’ve observed, inferred or know to be true through scientific principle

9. Example: Independent Variable: Cat fed a lot of food
Gained weight
Control Variable:
If _____________________________
then _______________________
because ____________________

10. How is the Variable changing?
Try to use INCREASE and DECREASE in your hypothesis!*
Ex. IF a cat receives an increase in the amount of food, THEN the animal will increase weight BECAUSE more calories are consumed.
* Or similar words showing growth or loss

11. Remember Try to keep your statement in 3rd person
This means no I, you, she, he, they etc.
Ex. If dry bread and moist bread are left in bags for two weeks, then the moist bread will grow mold more quickly than the dry bread, because mold is a living organism, and organisms need water to survive

12. Your because statement should not restate your if statement.
Avoid Circular Logic
Your because statement should not restate your if statement.
Ex. If I water my plant twice a day, then the plant will grow more quickly, because the plant is watered twice a day.
If I water my plant twice a day, then the plant will grow more quickly, because organisms require moisture in order to survive.

13. Now Try it on Your Own!
Come up with your own hypothesis related to cell phone usage. Identify your (IV, DV, CV). Add
this in your Cornell notes