The Scientific Method: Tutorial

1. Start from beginning The Scientific Method: Tutorial Designing the experiment Variable practice Graphing the data Conclusion

2. Introduction: The Scientific Method The scientific method is a series of steps used by scientists to help them solve problems. A valid experiment will identify a problem, research the problem to see if others have collected data for similar problems, create a hypothesis, collect data by performing an experiment, analyze the data collected, and report the findings. .

3. Experimental Design • Setting up the experiment can be the toughest part of the scientific method for young scientists. A poorly designed experiment can make your data hard to understand and even meaningless. Therefore, the purpose of this tutorial is to help you learn basic fundamentals to help you design an experiment and interpret the data collected.

4. back Identifying a Problem Simons-mycin (fictional) is a prescription medication designed to relieve arthritis pain. Jane and Jerry are both young doctors who have heard rumors that Simons-mycin can raise the blood pressure of patients who use the drug. This can be a serious medical concern because if the patients blood pressure is too high, they can suffer a heart attack and possibly die. This is the first stage of the scientific method, identify a problem. What is the problem that Jane and Jerry have identified? But what is the connection? But what is the connection? Some patients take Simons-mycin. Some patients are at risk of heart attack. This information is not given in the story. Correct. Some patients have high blood pressure. Some patients who take Simons-mycin may have higher blood pressures.

5. back Researching the Problem Jane and Jerry have agreed to meet at the UCLA medical library to research their problem. They searched countless journals to see if other doctors have performed work on the effects of Simons-mycin, but they did not find the answer to their problem question. They will need to perform their own experiment. Even though Jane and Jerry have discussed the risks with their patients about the use of Simons-mycin, they have found volunteers to test the medication. Together, Jane and Jerry come up with a plan to test Simons-mycin and the possible blood pressure risk. Now that Jane and Jerry have identified their problem and performed research, it is time for them to create a hypothesis that answers their problem. Remember, the problem they are trying to answer is: “Does Simons-mycin raise the blood pressure of their patients?”

6. Now that Jane and Jerry have identified their problem and performed research, it is time for them to create a hypothesis that answers their problem. Remember, the problem they are trying to answer is: “Does Simons-mycin raise the blood pressure of their patients?”

7. Creating the Hypothesis back If a person uses Simons-mycin, then they may have higher than normal blood pressure. If a person is overweight, then they may have higher than normal blood pressure. If a person has high blood pressure, then they must use Simons-mycin. This may be true also but Jane and Jerry are not testing a person’s weight. This could be another experiment to perform at a later date though. Correct. Press the NEXT button when ready. There is no reason to believe this. There are numerous reasons why a person could have high blood pressure. Now that Jane and Jerry have identified their problem and performed research, it is time for them to create a hypothesis that answers their problem. Remember, the problem they are trying to answer is: “Does Simons-mycin raise the blood pressure of patients?” The hypothesis is a possible solution to this problem and should be worded as an “If…then” statement. Click on the box below that would be a possible solution to this problem. Which will be our hypothesis?

8. Designing the Experiment back Jane and Jerry are ready to design and perform their experiment to test their hypothesis. But how do you design an experiment in the first place? Keep in mind our problem question: “Does Simons-mycin affect a person’s blood pressure?” Their experiment will need to test the blood pressure of volunteers. Jane and Jerry have found 50 patients who are willing to volunteer for this experiment. Valid experiments usually create two groups of test subjects. One group is called the CONTROL group. Participants of this group are not given the desired treatment (Simons-mycin). Therefore, the control group is used as a comparison group. The second group is called the EXPERIMENTAL group. Participants of this group are given the desired treatment (Simons-mycin). The experimental subjects will be compared to the control group to see if the treatment worked or not.

9. Designing the Experiment back Group A: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were not given Kobe-cyol. The 25 patients were instructed to eat and exercise according to specific instructions. After one month, the 25 patients would return to have their blood pressures checked again. Group B: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were given typical doses of Kobe-cyol. The 25 patients were instructed to eat and exercise according to the same instructions as group A. After one month, the 25 patients would return to have their blood pressures checked again. Is Group A the control group or the experimental group? Experimental group Control group Not quite. Remember that the experimental group is given the treatment. In this case, group A is not given Kobe-cyol. Correct. Because no treatment was given to Group A, that makes them the control group. Jane and Jerry decide to separate the 50 people randomly into two groups of 25 patients each.

10. Designing the Experiment back Group A: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were not given Kobe-cyol. The 25 patients were instructed to eat and exercise according to specific instructions. After one month, the 25 patients would return to have their blood pressures checked again. Group B: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were given typical doses of Kobe-cyol. The 25 patients were instructed to eat and exercise according to the same instructions as group A. After one month, the 25 patients would return to have their blood pressures checked again. Is group B considered the control group or the experimental group? Experimental group Control group Not quite. The control group is the one that does not receive treatment. Group B does receive treatment. Correct. Since group B received the treatment (Kobe-cyol) they are the experimental group. Jane and Jerry decide to separate the 50 people randomly into two groups of 25 patients each.

11. Identifying Variables back Group A: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were not given Kobe-cyol. The 25 patients were instructed to eat and exercise according to specific instructions. After one month, the 25 patients would return to have their blood pressures checked again. Group B: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were given typical doses of Kobe-cyol. The 25 patients were instructed to eat and exercise according to the same instructions as group A. After one month, the 25 patients would return to have their blood pressures checked again. The independent variable is the factor that differs between the control group and experimental group. A good experiment should only have 1 difference between the two groups. If there were accidentally more than 1 independent variable and the patients blood pressure changed, we would not know which factor was responsible. Number of people Diet habits Medication taken Exercise habits No. Each group had 25 people. No. Each group followed the same habits. Correct. No. Each group followed the same habits. What is different between Group A and Group B? (What is the independent variable of this experiment?)

12. Identifying Variables back Group A: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were not given Kobe-cyol. The 25 patients were instructed to eat and exercise according to specific instructions. After one month, the 25 patients would return to have their blood pressures checked again. Group B: To start, the 25 patients had their blood pressures recorded. Then, the 25 patients of this group were given typical doses of Kobe-cyol. The 25 patients were instructed to eat and exercise according to the same instructions as group A. After one month, the 25 patients would return to have their blood pressures checked again. The data measured will be the dependent variable. What is the dependent variable? No. Body weights are never mentioned or collected. No. This is the independent variable because it is what differs between group A and group B. Body weight Blood pressure Simons-cyol taken Heart rates Correct. It is called the dependent variable because the patient’s blood pressure may depend on the use of Simons-cyol. No. Heart rates are never mentioned or collected.

13. back Variable Practice: Farmer Bob Before proceeding, let’s stop for a moment and get some practice identifying variables and parts of an experiment. Farmer Bob has always used Grow-Rite Fertilizer on his crops, but wants to try Ever-Grow Fertilizer. He sections off two large areas of his field. In section A, he waters his crops as usual and adds Grow-Rite. In section B, he waters his crops as usual but adds Ever-Grow fertilizer. After 1 growing season, he records the growth of the crops. What is the independent variable of Farmer Bob’s experiment? Hmmm. Remember the independent variable is what differs between the two groups. Try again. Group A crops The type of fertilizer used Group B crops The height of the crops Hmmm. Remember the independent variable is what differs between the two groups. Try again. Correct. Hmmm. Remember the independent variable is what differs between the two groups. Try again.

14. back Variable Practice: Farmer Bob Before proceeding, let’s stop for a moment and get some practice identifying variables and parts of an experiment. Farmer Bob has always used Grow-Rite Fertilizer on his crops, but wants to try Ever-Grow Fertilizer. He sections off two large areas of his field. In section A, he waters his crops as usual and adds Grow-Rite. In section B, he waters his crops as usual but adds Ever-Grow fertilizer. After 1 growing season, he records the growth of the crops. What is the dependent variable of Farmer Bob’s experiment? Correct. The type of fertilizer used Group A crops Group B crops The height of the crops Hmmm. Remember the dependent variable is the data collected. Try again. Hmmm. Remember the dependent variable is the data collected. Try again. Hmmm. Remember the dependent variable is the data collected. Try again.

15. back Variable Practice: USA Military The United States military wants to see if soldiers with only 4 hours of sleep can operate at the same level as those who normally get 7 hours of sleep. One hundred soldiers are allowed to only sleep for 4 hours a night and another hundred are allowed to sleep for 7 hours a night. During the day, the soldiers are tested for marksmanship on the firing range. What is the independent variable of the military experiment? . . . Hmmm. Remember the independent variable is what differs between the two groups. Try again. Correct. The ammunition used Amount of sleep given Score on the firing range The number of soldiers Hmmm. Remember the independent variable is what differs between the two groups. Try again. Hmmm. Remember the independent variable is what differs between the two groups. Try again.

16. back Variable Practice: USA Military The United States military wants to see if soldiers with only 4 hours of sleep can operate at the same level as those who normally get 7 hours of sleep. One hundred solders are allowed to only sleep for 4 hours a night and another hundred are allowed to sleep for 7 hours a night. During the day, the soldiers are tested for marksmanship on the firing range. What is the control group of the military experiment? Hmmm. Remember the control group are those who are not given the experimental treatment. Try again. Correct. Soldiers with 7 hours sleep Soldiers with 4 hours sleep Score on the firing range The number of soldiers Hmmm. Remember the control group are those who are not given the experimental treatment. Try again. Hmmm. Remember the control group are those who are not given the experimental treatment. Try again.

17. back Variable Practice: USA Military The United States military wants to see if soldiers with only 4 hours of sleep can operate at the same level as those who normally get 7 hours of sleep. One hundred solders are allowed to only sleep for 4 hours a night and another hundred are allowed to sleep for 7 hours a night. During the day, the soldiers are tested for marksmanship on the firing range. What is the dependent variable of the military experiment? Hmmm. Remember the dependent variable is the data collected. Try again. Hmmm. This was the independent variable. Try again. The ammunition used Amount of sleep given Score on the firing range The number of soldiers Hmmm. Remember the dependent variable is the data collected. Try again. Correct.

18. back Back to Our Experiment Let’s look at the blood pressures at the start of this experiment. Where’s the data Jerry? I have it right here Jane. At the start of the experiment, remember that everyone had their blood pressures measured. On average, both the control group and the experimental group had a systolic blood pressure of 120. This is a fairly healthy blood pressure. Click the “? Buttons” below to continue. ? ? Did you click both boxes? If so, click here next.

19. Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10 Day 11 Day 12 Day 13 Day 14 Day 15 Day 16 Day 17 Day 18 Day 19 Day 20 Day 21 Day 22 Day 23 Day 24 Day 25 Day 26 Day 27 Day 28 Day 29 back

20. back 1 Month Later I’m so anxious. I hope our hypothesis was valid. Finally our experiment is finished. It’s been 30 days. Let’s see the data. After one month all 50 people returned to have their blood pressure examined. Click the “?” boxes below to reveal the results. Those who were not using Kobe-cyol maintained their healthy blood pressure of 120. However, those who used Kobe-cyol now had an average blood pressure of 145. Time to make our graph. ? ?

21. A title needs to be clear to a reader. Avoid titles such as “Biology graph” and “Our data” because these titles don’t tell us what the graph really shows. Click on the good title. Now we need to label the X and Y axis. back Graphing the Data No. This is too vague. The results of a month long test Affects of Kobe-Cyol on blood pressure Affects of Simons-cyol on blood pressure Graphs makes our data easier to understand. Others will read our results once we share our findings. Pictures are worth a thousand words after all. We better be clear about the data. Let’s start with the title.

22. back Graphing the Data Affects of Simons-Cyol on blood pressure Again. Be specific. Which label is specific on the Y axis? Now for the X axis. Which is specific? Amount of what? This is too vague. Amount Blood pressure values (mm Hg) Blood pressure values (mm Hg) Be specific. Patients who used Patients who did Simons-cyol for 1 month not use Simons-cyol Patients who used Kobe-cyol for 1 month Patients who did not use Kobe-cyol Two groups of people

23. back Graphing the Data Affects of Kobe-Cyol on blood pressure Keep in mind our data. Control group: Start: 120 End: 120 Experiment group: Start: 120 End: 145 We must use equal intervals to number the Y axis. 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 Blood pressure values (mm Hg) Patients who used Simons-cyol for 1 month Patients who did not use Simons-cyol

24. back Graphing the Data Affects of Kobe-Cyol on blood pressure Since we have before and after results, we need two different bar patterns. Striped bars will be the start of data collecting. Dotted bars will be the end of the data collection. So now we need to add a key so the readers of our graph know this. 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 KEY stripes = start of the test dots = end of the test Blood pressure values (mm Hg) Patients who used Kobe-cyol for 1 month Patients who did not use Kobe-cyol

25. back Graphing the Data Affects of Simons-Cyol on blood pressure Now we are ready to fill in the graph itself. Let’s graph the people who used Simons-cyol first. People who used Simons-cyol (Experiment group): Start: 120 End: 145 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 KEY stripes = start of the test dots = end of the test Blood pressure values (mm Hg) Patients who used Simons-cyol for 1 month Patients who did not use Simons-cyol

26. back Graphing the Data Affects of Kobe-Cyol on blood pressure Now let’s graph the people who did not use Kobe-cyol. People who did not use Kobe-cyol (Control group): Start: 120 End: 120 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 KEY stripes = start of the test dots = end of the test Blood pressure values (mm Hg) Patients who used Kobe-cyol for 1 month Patients who did not use Kobe-cyol

27. back What is the data telling us? Affects of Kobe-Cyol on blood pressure To determine what could have caused the jump in blood pressure, we need to examine what was different between the two groups of people? Number of people Exercise habits Diet habits Length of testing time Type of medication taken 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 correct KEY stripes = start of the test dots = end of the test different same correct Blood pressure values (mm Hg) different same correct different same correct different same different same correct Patients who used Kobe-cyol for 1 month Patients who did not use Kobe-cyol

28. back What is the data telling us? same Affects of Simons-Cyol on blood pressure Number of people Exercise habits Diet habits Length of testing time Type of medication taken If the only change between the two groups was the type of medication taken, then that must be the reason for the increased blood pressure. I hope you see the importance of only 1 independent variable. same 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 same KEY stripes = start of the test dots = end of the test same different Blood pressure values (mm Hg) Patients who used Simons-cyol for 1 month Patients who did not use Simons-cyol

29. back What about the Hypothesis? Affects of Simons-Cyol on blood pressure One experiment proves nothing. More tests are required to state this. Now that our graph is finished, what does it tell us about our hypothesis? If you forgot, the hypothesis was: If a person uses Simons-cyol, then they may have higher than normal blood pressure. 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 The hypothesis was proven correct. KEY stripes = start of the test dots = end of the test Correct. The hypothesis appears valid. Blood pressure values (mm Hg) Are you sure? The data agrees with the prediction. The hypothesis is proven wrong. Are you sure? The data agrees with the prediction. The hypothesis appears wrong. Patients who used Simons-cyol for 1 month Patients who did not use Simons-cyol

30. back I think we should take the 25 patients off Simons-cyol immediately and continue to monitor their health. Stating a Conclusion Wow! I know it is only 1 experiment, but we need to report our findings so others can check our work. A conclusion should be a clear and understandable summary of the main idea learned from the experiment. Be straight to the point. What would a good summary be? Correct This may be true, but it is too vague. This may be true, but it is not the main idea learned. Simons-cyol appears to raise the blood pressure of normal individuals. Our experiment was valid and well deigned. Simons-cyol makes people sick and unhealthy. Simons-cyol was the independent variable of this experiment. This may be true, but it is too vague.

31. back Reporting your results In order for others to confirm our findings, our results need to be shared with others. There are many journals that collect research performed by scientists around the world. Even newspapers and magazines will often pick up on a study of great importance. This is how information is spread around the world about various scientific findings. Experiments are valid when the rules of the scientific method have been followed. This method reduces errors, eliminates bias, and advances our understanding of the world in which we live. Let’s Review: #1) What is a tentative solution to a problem called? Try again. This is the factor differing in an experiment. Try again. This is the data collected. Try again. This is the comparison group. Correct. hypothesis independent variable dependent variable control group

32. back Review #2 Which variable differs between the control group and the experimental group? Dependent variable Independent variable This is the data that is collected because of the change. Correct

33. back Review #3 Which hypothesis best fits the problem question below? Problem question: Why do some people develop diabetes? A diet that is high in sugar can lead to diabetes. That may answer the question, but it is not worded in proper format. That may answer the question, but it is not worded in proper format. Diabetes is caused by a high sugary diet. Correct. If a person has a diet that is high in sugar, then that may lead to diabetes.

34. back Review #4 Pretend our control group had 35 people exercise according to a different plan than the 25 people of the experimental group who still took Simons-cyol for 1 month. How many variables would be in this experiment? ONE TWO THREE Recount. How many times do the control group and experimental group differ according to the question? Recount. How many times do the control group and experimental group differ according to the question? • Correct. • Different number of people • Different exercise program • Use of Simons-cyol

35. back Review #5 Pretend our control group had 35 people exercise according to a different plan than the 25 people of the experimental group who still took Kobe-cyol for 1 month. Why is this a poorly designed experiment? There are too many different variables between the control and experimental groups. The dependent variable is not different from the control group. There are no independent variables to this experiment. Correct. Valid experiments only differ once. This statement is confusing actually. How many differences should exist between the control and experimental groups? That’s not true. There are actually multiple variables.

36. back The end! You will be expected to use the scientific method throughout the course of the school year. I hope this tutorial simplified how it can help solve problems. Be sure your name is on your paper before submitting your work.