The Scientific Method

1. The Scientific Method • The Scientific Method is a systematic approach to PROBLEM SOLVING.

2. Scientific Method Steps • STATE THE PROBLEM /gather information • Form a hypothesis • List materials • Write a procedure to test my hypothesis • Conduct the experiment • Record and analyze data collected • Draw a conclusion

3. State the problem • The problem you are trying to solve is stated in the form of a QUESTION. • Investigate a problem that interests YOU!! • Example: A gardener might ask… • Which fertilizer works the best on bean plants?

4. Gathering Information • Make OBSERVATIONS and INFERENCES on your problem. • Think of any prior experiences that you have had that could help. • Example: • The gardener has used Wal-Mart brand before and the plants did not do well. He also used Miracle Grow and it worked better, but not with bean plants.

5. Forming a Hypothesis • A hypothesis is an educated GUESS or prediction of results. • Should be written in an “IF…THEN…”format. • The “If” part of the hypothesis is a summary of your experiment. • The “Then” part of the hypothesis is your prediction of what will happen in the experiment. • You will be proving it RIGHT or wrong…It is ok to prove your hypothesis wrong!!

6. Forming a Hypothesis • Example: • If I plant 3 bean plants in 3 types of fertilizers, then I think the miracle grow plant will grow the tallest.

7. Materials • Before beginning your EXPERIMENT, you must create a detailed LIST of MATERIALS that you will use. EXAMPLE Materials: • 3 lima bean seeds • 1 cup Miracle Grow fertilizer • 1 cup Wal-mart brand fertilizer • 1 cup Fertilizer X • 3 pots (all the same size) • measuring cup • water • sunlight • Metric ruler • Paper & pencil

8. Procedure • You need to list ALL steps that you plan to execute during your experiment. This is your PROCEDURE. The procedure should read like a set of directions. Include ALL details, EVERYTHING YOU DID!!!

9. EXAMPLE Procedure: 1. Gather all materials listed in the materials section. 2. Fill the first flower pot with 1 cup of Miracle grow. 3. Place 1 bean seed 3 cm deep into the soil inside the center of the pot. 4. Label this planter “Plant A: Miracle grow” 5. Fill the second flower pot with 1 cup of Wal-mart brand fertilizer. 6. Place 1 bean seed 3 cm deep into the soil inside the center of the pot.

10. 7. Label this planter “Plant B: Wal-Mart Brand fertilizer” 8. Fill the third flower pot with 1 cup of fertilizer X. • Place 1 bean seed 3 cm deep into the soil inside the center of the pot. • Label this planter “Plant C: Fertilizer X” • Place plants near a window where all three will get the same amount of direct sunlight. • Give each plant 20 ml of water daily. • Measure the growth of each plant in cm each day and record the data on a data table.

11. Testing the Hypothesis • The experiment should test the HYPOTHESIS. • Within you experiment, you include VARIABLES or factors of the experiment. • Types of variables that you will have: • ONE independent variable • ONE dependent variable • MANY controlled variables or CONSTANTS.

12. INDEPENDENT a.k.a MANIPULATED variable– • The INDEPENDENT VARIABLE is the factor that the scientist changes. • This is the ONE variable that you are testing. Why do you think it is important to only change 1 thing at a time? (Remember I’m for independent /manipulated)

13. DEPENDENT a.k.a RESPONDING VARIABLE – • The DEPENDENT VARIABLE is factor that you are measuring or expect to change because of the INDEPENDENT variable. This is your data from the experiment (Remember Dr. for dependent/responding)

14. Testing the Hypothesis • In the fertilizer problem example: Manipulated a.k.a ____________ variable is the type of _________________ we are using, because we change or MANIPULATE those within the experiment. Responding a.k.a ____________ variable is what HAPPENS to the plant BECAUSE of the changes we made (the manipulated variable). So…What happens to the plant????

15. Testing the Hypothesis (cont.) • Controlled Experiment – an investigation in which the factors that influence the outcome are kept the same EXCEPT for the one whose effect is being studied. • Constants –All other factors which remain the same throughout the experiment except the one whose effect is being studied. • Example: • In our fertilizer experiment we would use the same: type of plant, temperature, amount of water, amount of sunlight. We would ONLY change one thing…the ______________.

16. Recording the Data/Results • Record all observations and measurements. • Just the facts, do not include any inferences here…put them in your conclusion! • Try to create a data table (a chart to help organize your data) • For example… (see next slide)

17. Fertilizer experiment Plant Growth in cm

18. Recording the Data/Results • On your data table always include a title and label each part. • Always make sure your measurements include units. • You can use your data table to create a graph.

19. Fertilizers affect on Plant growth

20. Conclusion • This is a SUMMARY of your investigation…include the answers to the following questions: • What happened in the experiment? 2. What did you learn from the experiment? 3. Why do you think your results happened? (This is where you put your inferences!) 4. Was the hypothesis correct? Why or why not? 5. Is there any data that does not “fit” the normal pattern? Could it be a mistake? Any potential for human error?

21. Conclusion (cont.) • Example: During my experiment to test the 3 different types of fertilizers, Fertilizer X helped the bean plant grow the fastest. Miracle grow was the second best and Wal-mart brand was the least effective fertilizer. My hypothesis was incorrect because I thought Miracle Grow would work the best. I noticed that fertilizer X had a lot of small white balls in the soil, which I think were little balls of plant food. I think that is why the bean plant that had fertilizer X grew faster than the others. Although I tried to give each plant the same amount of water, I accidently spilled a little more water into plant A on day 2. Since Plant A did not grow the tallest, I do not think this error affected my data. Next time, I will not pour the water into the graduated cylinder over the plant.