1. What is the purpose of using scientific method?
Warm-Up
What is the purpose of using scientific method?
Scientific Method

2. SCIENTIFIC METHOD: Cornell Notes
Left Side:
Key Ideas
Questions/Potential Quiz or Test Questions
Right Side:
Complete details, diagrams
Highlight vocabulary
Key ideas

3. The Steps a scientist uses to solve a problem
State the problem.
- usually in the form of a question
Background research
- collect information about the problem
Hypothesis
- an educated answer to the problem
Should be in the format: If…then statement

4. Parts of an experiment
4. Experiment
- A procedure that tests the hypothesis
An experiment includes:
a) Independent variable (IV) is the one variable that is changed by the scientist. The IV is plotted on the x-axis of a graph.
b) Dependent variable (DV) is the variable affected by changing the IV variable. The DV is the result of the change of the IV.

5. Parts of an experiment
4. Experiment (cont.)
- A procedure that tests the hypothesis
An experiment includes:
c) Control is the group that remains unchanged. It’s used to compare the results of the experimental group and is usually the ‘normal’ conditions
d) Constants are all factors in an experiment that are kept the same. Constants make the experiment fair.

6. The final steps
5. Data/Results - collect & record data observed in the experiment - results can be qualitative (descriptive) or quantitative (numerical) 6. Conclusion - Ask yourself, “Does the data support my hypothesis? Why or why not? - Be aware of experimental and human errors.

7. What is theory?
- theory: something that is considered to be true and can be repeated.

8. Picking Out the Parts of an Experiment
SCENARIO 1:
A student wants to see if a new, more costly fish food will cause fish to grow faster. She separated the fish into two groups of three fish each. Group one received the old fish food. Group two received the new fish food. The length of the fish is measured each week.
What is the dependent variable? ___________________________________
What is the independent variable? ___________________________________
What is the control? ___________________________________
What are the constants? ________________________________________________________________

9. Picking Out the Parts of an Experiment
SCENARIO 2: In the laboratory, yeast cells are usually grown at a temperature of 25oC. A scientist wanted to determine if yeast cells would reproduce faster or slower when the temperature was dropped to 15oC. The same number of yeast cells were placed in the same medium with the same amount of nutrients. One sample was kept at 25oC and the other one was kept at 15oC. The number of yeast cells was counted every hour for an eighteen hour period. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ ________________________________________________________________

10. Picking Out the Parts of an Experiment
SCENARIO 3: Mary wondered if a more costly fish food would cause her fish to grow faster. She separated her fish into two groups of three fish each in two 10-galon tanks. The fish received the same amount of food at the same times of the day for one year. The first group was given the cheap food and the second group was given the more costly food. She measured the length of the fish every month at the end of the month. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ ________________________________________________________________

11. Picking Out the Parts of an Experiment
SCENARIO 4: Ron wondered if color affects the rate of thermal energy absorption. He took five 12-oz. Aluminum cans and painted them yellow, white, black, and blue. The fifth one he left plain. He then poured equal amounts of water into each and placed them on a shelf next to a window and measured the temperature of the water every five minutes for 1 hour. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ ________________________________________________________________

12. Picking Out the Parts of an Experiment
SCENARIO 5: A student wanted to determine what effect the lack of sunlight has on green plants. She took 2 small green bean plants of the same size and placed them in two 10oz. Styrofoam cups with a hole in the bottom of each. She covered each plant with 5oz. of soil. One plant was placed in full sunlight and one was placed in complete darkness. She watered each bean plant once a week with 10ml of water and measured each plant’s height. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ ________________________________________________________________

13. Picking Out the Parts of an Experiment
SCENARIO 6: To determine the effect of ammonium sulfate (NH4)2SO4 on plant growth, two seed flats (a large platform with seeds on it) containing soil from a lawn were seeded using standard lawn grass mixtures. One flat was watered with rainwater and the other with rainwater containing a little ammonium sulfate. The flats were kept in the same area to ensure identical conditions and temperatures. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ _______________________________________________________________

14. Picking Out the Parts of an Experiment
SCENARIO 7: An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied with identical amounts of bacteria as food, received the same amount of light, and had their temperature maintained at 200C. Every two hours, water fleas from both populations were selected and their heartbeats were monitored. The fleas of population #1 had caffeine administered five minutes before the heartbeats were checked. The fleas of population #2 were given nothing extra. What is the dependent variable? ___________________________________ What is the independent variable? ___________________________________ What is the control? ___________________________________ What are the constants? ________________________________________________________________ ______________________________________________________________________

15. Application: Penny Lab
Focus on the Scientific Method of the LAB
MAKE Sure that you have read each question completely and
MAKE Sure that you answer each question in DETAIL (reference your notes)

16. Closing: Summarize Your Notes/Lab
Use Key Vocabulary words to summarize” What are the elements of the process of Scientific Method? Make sure your lab is complete.