2. Steps in the Scientific Method

3. Ask a Question First, there must be a problem to solve.
Based on observations
Why is a good question important?
Helps guide your research
Helps you stay focused  should be specific

4. Hypothesis A suggested solution to the problem. Must be testable
Predicts an outcome
Written as If…Then…Because… statements
If __IV__ is true, Then ___DV___ will happen because __reasoning_.

5. variables
Variable – factor in the experiment that is being tested or measured
A good or“valid” experiment will only test ONE variable!

6. Independent vs. Dependent Variables
The factor that is changed is known as the independent variable.
The factor that is measured or observed is called the dependent variable.
QUESTION:
Does fertilizer affect plant growth?

7. What would be some constants in this experiment?
Constant variables
The experimenter makes a special effort to keep other variables constant in the experiment so that they will not effect the outcome.
NO fertilizer
What would be some constants in this experiment?
Fertilizer

8. Control group vs. Experimental Group
The Control group
is used for COMPARISON
does NOT include the independent variable
Can only be ONE group
NO fertilizer
The Experimental group
includes the independent variable you are testing
Which is the control group? Experimental group?
Fertilizer

9. Practice Hypothesis Statements
QUESTIONS:
Does the source of sunlight have an effect on the growth of a plant?
Does temperature have an effect on the color of a plant’s leaves?
Does the amount of time you study have a positive effect on your grades?

10. Practice Hypothesis Statements
1. Does the source of sunlight have an effect on the growth of a plant?
If a plant grows best in natural lighting then a plant grown outside will grow better than a plant grown inside because it is being exposed to sunlight.
2. Does temperature have an effect on the color of a plant’s leaves?
If plants are grown at higher temperatures then those plants will have browner leaves because the intense heat will dry out the leaves.
3. Does the amount of time you study have a positive effect on your grades?
If you spend more time studying for your tests, then your grades will go up because you will know the material better.

11. Test your hypothesis

12. One more thing… it is best to make several trials with each independent variable.

13. Data Results of the experiment
May be quantitative (numbers) or qualitative
Must be organized
Can be organized into charts, tables, or graphs
Independent variable goes on the X-axis
Dependent variable goes on the Y-axis

14. Conclusion
The answer to the hypothesis based on the data obtained from the experiment
Was the hypothesis “supported” or “not supported” by the evidence

15. In order to verify the results, experiments must be retested.

16. Steps in the Scientific Method