1. Hypothesis

2. Definition
A testable explanation for an observation or scientific problem . Written as an IF, THEN statement.

3. A hypothesis statement must be testable.
Is NOT a fact.
Is more than a guess. Is based on prior observations and research.
A type of prediction about the effect an independent variable will have on a dependent variable.

4. Writing a hypothesis statement
IF, THEN statement
IF (Independent Variable), THEN (Dependent Variable).

5. Helpful Ways to think of the Hypothesis Statement
“If I change the IV, then I think the result (DV) will be.”
If the (independent variable) (describe how you change it)
Then the (dependent variable) will (describe the effect).

6. Example Statement
If the amount of salt added to ice is increased (independent Variable) (describe how you change it) then the temperature of the mixture will decrease. (Dependent Variable) (describe the effect)

7. Spot the Hypothesis Which of the following is a hypothesis statement?
The Earth’s crust contains 90 elements
Magnetism and gravity are not the same
If the length of a vibrating cord is increased then the sound will become louder.

8. A. If cloud cover serves as an insulator, then the surface temperature of the earth should get colder on cloudless nights. B. Green leaves manufacture food, stems transfer food and roots store the food. C. Algae are living things.

9. Baking powder is used in biscuits
The brighter color of an orange, the juicier the fruit.
If the amount of antifreeze increases, the temperature at which the mixture freezes gets lower.