1. The Scientific Method
5 Steps to Follow!

2. A Brief Refresher on the Scientific Method
Hypothesis:
An idea or explanation that you then test through study and experimentation.
Variable: Anything that changes in an experiment.  There are 2 types:            Independent:  What you change on purpose (cause)            Dependent: What you observe changing, or                                What you measure/observe (effect)

3. The Scientific Method
The Scientific Method is a series of steps to follow to answer a question or solve a problem
- There are 5 main steps

4. Step 1: Ask a Question
Scientists ask questions based on observations from their surroundings

5. Step 2: Form a Hypothesis
Take an educated guess about what you think the answer is to your question

6. Step 3: Test your hypothesis
Set up an experiment to test your question

7. Step 4: Analyze Your Results
Look at your results and decide what they tell you about your question

8. Step 5: Form a Conclusion
Decide what the answer to your question is and ask:
Was my hypothesis right or wrong?
Do I need to do the experiment again to find out more?

9. Hypothesis

10. Form a Hypothesis
Hypothesis: an educated guess or prediction; an “if, then” statement If ____independent variable______ then__dependent variable_______

11. Example:
Independent Variable: I feed my cat a lot of food Dependent Variable she will get fat If ___________________________ then _________________________

12. Try to use INCREASE and DECREASE in your hypothesis!
Remember
Try to use INCREASE and DECREASE in your hypothesis!
Ex. IF I increase the amount of food I give my cat, THEN she will increase her weight

13. Identifying Variables
Step 4: Test your hypothesis

14. Types of Variables
There are 2 main types of variables: Independent Variable: The variable that is changed by the scientist; the ‘I control’ variable Dependent Variable: The variable that might change because of what the scientist changes – what is being measured

15. IV: Drinking Mountain Dew DV: the amount of sleep
Remember!
Your hypothesis can TELL you what your variables are!
Ex. If I drink Mountain Dew before bed, then I will not sleep very much.
IV: Drinking Mountain Dew
DV: the amount of sleep

16. Practice
Use this hypothesis to identify the variables: If I leave all the lights on all day, then my electric bill will be expensive IV: ______________________ DV: ______________________

17. If I brush my cat more, then there will be less fur on my furniture IV: ______________________ DV: ______________________

18. Now read the following experiment and identify the independent and dependent variables
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: ____________________________________

19. Example
Claim: Increasing the number of hours you study will increase test scores.
Hypothesis- If the number of hours of studying is increased, the test grades will increase.
IV- number of hours studying
DV- test grades
Constant- Number of hours studying, same subject, …
Control- a group who studies less hours or no hours

20. Example 2

21. Procedure All experiments need to have:
Constants- the parts of the experiment that must be kept the same in order to ensure that the results change due to the IV
Many repeated trials (Assume you have an unlimited money supply.)
An independent variable (IV)
Control Group- Describe the control group and explain why it was chosen to compare.
A dependent variable (DV)
Hypothesis that gives the relationship between the independent and dependent variables (If _____________, then _________)
Sketch of the Lab
Procedure

22. Procedure
1. Select an advertisement from the magazines provided by the teacher.
2. Design a valid experiment that focuses on what the magazine ad is claiming. The experiment must be within school regulations and must be G or PG rated.
3. Write a list of all steps for the procedure to complete this experiment. Things to consider might include:
how much of the product to use, how to choose the reactants or participants, how to measure the responses or variables, how many times to conduct experiment, what other conditions must be kept constant and how to do this, what types of experimental groups are used, etc.