1. Hypothesis and Variables

2. Form a Hypothesis
Hypothesis- a testable explanation of an observation.
A hypothesis is NOT just an educated guess about what you think will happen. It must be able to be tested!

3. Form a Hypothesis We write the hypothesis in an If-Then statement
ex: If the amount of fertilizer is increased, then the height of the plant will increase.

4. Variables & Controls
A variable is anything that changes in a scientific experiment.
The control is what you use to compare the results to in the end of the experiment.

5. There are 2 types of variables:
Independent
Dependent

6. Form a Hypothesis The Independent Variable goes after the “If” I.V.
If the amount of fertilizer is increased,
then the height of the plant will increase.

7. Form a Hypothesis The Dependent Variable goes after the “Then”
If the amount of fertilizer is increased,
then the height of the plant will increase.
D.V.

8. Now You Try:
If you spend more time studying, then your grade will improve.
Independent Variable =
Dependent Variable =

9. Now You Try:
If you spend more time studying, then your grade will improve.
Independent Variable = amount of time spent studying
Dependent Variable = grade

10. Now You Try:
If the temperature of the room is increased, then the bacteria will grow faster.
Independent Variable =
Dependent Variable =

11. Now You Try:
If the temperature of the room is increased, then the bacteria will grow faster.
Independent Variable = temperature of room
Dependent Variable = bacterial growth

12. Variables & Controls
A variable is anything that changes in a scientific experiment.
The control is what you use to compare the results to in the end of the experiment.

13. 2 Types of variables: Independent Variable: What you change.
Dependent Variable: What changes because of the Independent Variable.

14. 2 Types of variables: Independent Variable: Cause
Dependent Variable: Effect

15. Independent Variable Independent Variable: What you change. Cause
a.k.a Manipulated Variable
Graphed on x axis

16. Dependent Variable
Dependent Variable: What changes because of the Independent Variable.
Effect
a.k.a Responding Variable
Graphed on y axis

17. Independent Variable vs. Dependent Variable
Also Known As:
Manipulated Variable
Responding Variable
Results:
Cause
Effect
On a graph:
X axis
Y axis

18. After all of the data from the experiment is collected, then its time to organize the data.

19. Organize your data Put your data into a data table Independent
Variable
__________(unit)
Levels
Dependent Variable _______________ (unit)
Trial Trail Trail mean range

20. Organize your data Make the data table into a graph
GRAPHS make it EASIER to see patterns in the data!

21. Organize your data
How do you know what goes on each axis of the graph?

22. Organize your data DRY MIX
Dependent Variable = Responding Variable = Y axis
Manipulated Variable = Independent Variable = X axis

23. Parts of a graph
Y Axis
X Axis

24. Y Axis (Dependent Variable) X Axis (Independent Variable)
Parts of a graph
Y Axis (Dependent Variable)
X Axis (Independent Variable)

25. Graphing: DRY MIX
Dependent Variable
Independent Variable

26. Any Questions????