2. The Scientific Method

3. Click One of the Following To Start Your Tour l Testable Question l Writing A Hypothesis l Gathering Materials l Writing A Procedure l Conducting The Investigation l Recording Data l Drawing Conclusions and Sharing Results

4. The Testable Question (Problem) l Before you start an experiment you must have a reason to do it. l You need to have a question that can be answered through an investigation l This is called a “Testable Question.”

5. Examples of the Testable Question l Does the amount of sunlight a plant gets affect how it grows? l Does the size of the hole in the bottom of a sinking water clock affect how fast it sinks? l Does caffeine affect reaction time in middle school students? l Which disinfectant works the best on household germs?

6. These Are Not Testable Questions l Is Jerry Rice the best receiver of all time? l Does water smell good? l Is the cafeteria food good? l Will the school be open tomorrow? l You cannot answer these questions with an experiment. Opinion questions are not testable.

7. Gathering Materials l In order to do an experiment, you must make a list of the equipment you will use. l This list is written above your procedure. l It allows other people to do your experiment without having to ask you what they need.

8. Writing a Hypothesis l A hypothesis is an “educated guess” about the out come of your experiment. l In order to make this guess, you must rely on your background knowledge and the research which you conducted before you began planning the experiment.

9. Hypothesis and Research l It is VERY important that you conduct research before you make your hypothesis. This research will give you the information you need to make a hypothesis that is scientific and accurate.

10. A Well Written Hypothesis l A well written hypothesis consists of an “if” statement and a “then” statement. l The “if” statement contains information on what your are testing, and the “then” statement reflects your beliefs of the outcome of the experiment.

11. Examples l “If we change the size of a hole in the bottom of a funnel, then the funnel will sink at a faster rate” l “If caffeine is increased in someone’s body, then their reaction time will be quicker”

12. Writing A Procedure l A procedure is a list of steps that a scientist takes to complete the experiment. l This is a very detailed list that is numbered in 1,2,3..... order. It is not a paragraph! It may include drawings. l You know you have written a good procedure when someone can read it and do the experiment exactly like you did.

13. Water Clock Procedure l 1. Fill a clear, 4 liter bucket to 1 inch from the top l 2. Place funnel on the top of the water with the hole facing down l 3. Let funnel sink and record the time it takes to hit the bottom l 4. Record this time in a data table l 5. Take the funnel out of the water and place one, 3/4 inch brass washer inside the funnel. l 6. Repeat steps 2 through 4. l 7. Repeat step 5 by adding two, 3/4 inch brass washers inside the funnel. l 8. Repeat steps 2 through 4 l 9. Repeat step 5 by adding three, 3/4 inch brass washers inside the funnel. l 10. Using your data table, make a line graph representing the sinking times of all three funnels.

14. Conducting The Investigation l It is now time to start testing your hypothesis! l This is the step that we all want to jump right into. However, it is very important that we complete the previous steps first. l Safety is always an issue here. Be sure to follow all lab safety procedures while conducting the investigation

15. Investigation l If you have written a detailed procedure, your investigation should go smoothly. l Simply follow the steps in your procedure!! l Be sure to clean up your materials when you have finished!

16. Recording Data l All measurements in an investigation need to be recorded in a data table. l The table must have a title (related to what you are measuring), and appropriate labels for the rows and columns. Sinking Time For Funnels (seconds) Trial Number 1 2 3 Avg. Number Of Washers 0 1 2 3 1109080 93.3 36314035 1217 15 12101412

17. Graphing Your Data Table l In order to understand and interpret you data, you need to make a graph. l A graph lets you see trends in the data and it also helps you look at the data in a way that is easy to understand. l Remember your labels!!

18. Drawing Conclusions l The final piece of the scientific method is drawing conclusions. l In this step we analyze our data and graphs and decide if our hypothesis was correct or incorrect! We always restate our hypothesis in our conclusion. l We discuss any trends we see and we attempt to explain why our hypothesis was correct or incorrect. l This is always in paragraph form! Conclusion In conclusion, I can say that my hypothesis (if we add more washers to the funnel, then it will sink faster) was correct. The funnel did sink faster when I added more washers. My graph shows a decrease in sinking time so I have proved that this is true.

19. Sharing Conclusions l To make our experiment complete we must share our findings with other people. l This can be through discussion or a lab report printed for a magazine. Scientists love to read about other’s experiments! Sinking Water Clocks

20. Quiz Page 1 Multiple Choice l 1. The first step in the scientific method is: –A. conducting an investigation –B. writing a testable question –C. writing a hypothesis –D. drawing conclusions

21. Quiz Page 2 l 2. Opinion questions are: –A. testable –B. not testable –C. scientific

22. Quiz Page 3 Multiple Choice l 3. After writing a testable question you need to: –A. start the investigation –B. write conclusions –C. gather materials

23. Quiz Page 4 l 4. An educated guess about the outcome of the investigation is called a: –A. guess –B. hippopotamus –C. hypothesis –D. hyperbole

24. Quiz Page 5 Multiple Choice l 5. A hypothesis must contain an “____, ____” statement: –A. here, now –B. if, not –C. if, then –D. why, why not

25. Quiz Page 6 l 6. In a well written hypothesis, the dependent variable can be found in the “____” statement. –A. if –B. then

26. Quiz Page 7 Multiple Choice l 7. When writing a procedure, it should contain lots of: –A. words –B. paper –C. details

27. Quiz Page 8 l 8. A procedure should be in _______ form. –A. paragraph –B. circular –C. square –D. list

28. Quiz Page 9 Multiple Choice l 9. If you have written a good procedure, someone should be able to do your experiment almost like you did. –A. True –B. False

29. Quiz Page 10 l 10. After writing a good procedure, it is time to start: –A. dancing –B. your engines –C. your investigation