1. Scientific Method

2. The scientific method is a logical, systematic approach to the solution of a scientific problem.
Make an observation
Qualitative-use your senses
Quantitative-make a measurement
2. Leads to a Question
3. Hypothesis-proposed explanation for an observation.

3. 4. Perform an Experiment
**Design a procedure to test 1 variable
There are 2 Types of Variables:
A. Manipulated/Independent variable: The variable that will be manipulated
B. Observed/Dependent variable: The variable that will change depending on the independent variable.
**In order for results to be accepted, anyone must be able to repeat experiment with the same results.

4. 5. Analyze Results
If your results prove your hypothesis, then a theory can be developed.
If your results do not prove your hypothesis, then return to step 3. (Propose a new hypothesis)

5. Theory vs. Law
Theory: a well tested explanation for a broad set of observations.
**Theories can never be proved-means that there is room for it to be changed.
Law: Statement that summarizes many observations or experiments.

6. Theory or Law? Pressure is caused by particles moving very fast.
Atoms combine because of charged particles.
Compounds have a definite composition.
Total mass is the same before and after a reaction.
Light is caused by energy being released in the form of waves.
Heat flows from hot areas to cold areas.
Theory
Theory
Law
Law
Theory
Law

7. Ms. G wants to find out which bug spray works best: Off, Avon, or Cutter.
What should be kept constant (the same) over the course of the experiment?

8. These are the results: Group 1 (OFF): 4 mosquito bites
Group 2 (Avon): 18 mosquito bites
Group 3 (Cutter): 10 mosquito bites
Group 4 (None): 28 mosquito bites

9. Which group was the control?
What is the independent variable? (what did I change each time?)
Brand of Bug spray
What is the dependent variable? (what changed because of the type of spray used?
Number of Mosquito bites
What should be her conclusion?
OFF Brand is the most effective in reducing the number of mosquito bites.

10. Scenario #1:
You read in the paper that the number of dead tadpoles along the Yadkin River has increased over the past few years. Since you are an inquisitive teen you want to know why. After examining all of the data available in the library, you decide to go with a hypothesis that increased Ultraviolet (UV) radiation from the deterioration of the ozone is killing off the tadpoles.

11. 1. How many steps in the scientific method have been accomplished
1. How many steps in the scientific method have been accomplished? Identify them.
Make an Observation-decreased number of tadpoles.
Ask a Question-What is killing the tadpoles.
Hypothesis-UV radiation from the hole in the ozone layer is killing off the tadpoles.

12. You design an experiment with two groups of tadpoles
You design an experiment with two groups of tadpoles. Group 1 has 100 tadpoles in a 5 gallon drum of water covered by a piece of glass. You read at the library that glass filters out UV radiation so that none will reach the interior of the container. The second group is set up exactly like Group 1 except it has acrylic plexiglass, which will not filter UV radiation out. You place the groups outside for a month with a regular feeding schedule and then observe the results.

13. What is the independent variable and what is the dependent variable?
Which is the control group?
What is the difference between the two groups?
What other factors have you attempted to control with this experimental setup?
Independent-exposure to UV light
Dependent-number of dead tadpoles
Group 1-no UV radiation
Exposure to UV radiation
Size of container, number of tadpoles, water, food, temperature, time of experiment

14. 6. Does the information from this experiment support the hypothesis?
Group 1
Group 2
Initial number of tadpoles
100
Final number of tadpoles 96 95
6. Does the information from this experiment support the hypothesis?   
7. If no, then what might be causing a decrease in the tadpole population?
No-the data doesn’t show any change.
What do you think?

15. Scientific Method Activity
The idea of science is built on evidence that can be observed or deduced from the natural world. We gather evidence through the use of our senses. However; the evidence can be confusing.
Data (evidence) is not always consistent or available, so this is why scientific explanations are “tentative” explanations of natural phenomena.
In this activity, you will be provided with many clues that may be used to develop an explanation (hypothesis).

16. Check Lab Scenario
There used to be a family that lived in a house on 1065 Missing Lane. No one has seen them in over a month, and you and your detectives must figure out what happened to them.
These envelopes contain a bunch of checks found in diffferent drawers inside of their home.
You must collaborate within and outside of your groups to solve this mystery.
You will see that as you acquire more evidence, it will change your hypothesis.

17. Checks Lab Instructions
Students will separate into groups of 4.
Each group of 4 will receive an envelope.
Open your group envelope and randomly take out 4 checks without looking at them.
Use the evidence from the checks to develop a hypothesis for what you think happened with this family.
Open your envelope and remove four more checks. Construct a new hypothesis
Now, remove the last 2 checks and modify your hypothesis for the last time.
You should have 6 remaining checks in your envelopes, which you MAY NOT look at.
Collaborate with the other groups to see if you can agree on a hypothesis as a class.

18. DISCUSSION QUESTION
Which steps of the scientific method did you use in the Mystery Checks Activity?
Which steps of the scientific method did you not use in the Mystery Checks Activity?
Did you have to modify your original hypothesis? How many times? What caused that modification?
Did you at any point allow your personal biases to influence your hypothesis?