1. The Scientific Method

2. What is the Scientific Method? A logical problem solving process to investigate a scientific problem. A logical problem solving process to investigate a scientific problem. No one completely correct set of steps No one completely correct set of steps –Depends on problem/research

3. Steps in the Scientific Method State the Problem State the Problem State the Problem State the Problem Research Research Research Form a Hypothesis Form a Hypothesis Form a Hypothesis Form a Hypothesis Design an Experiment Design an Experiment Design an Experiment Design an Experiment Test the Hypothesis Test the Hypothesis Test the Hypothesis Test the Hypothesis Organize the Data Organize the Data Organize the Data Organize the Data Draw Conclusions Draw Conclusions Draw Conclusions Draw Conclusions

4. State the Problem Observe a discrepancy Observe a discrepancy –Doesn’t belong –Unexpected Can’t solve a problem if it isn’t understood Can’t solve a problem if it isn’t understood Example: My snow peas aren’t producing many pods.

5. State the Problem State the problem as a question State the problem as a question –Can’t be answered by Yes or No. –Use: How, When, What, Where, and Why Specific but not cumbersome Specific but not cumbersome Must be testable Must be testable Two variables Two variables –Independent –Dependent Example: Will fertilizer increase snow pea pod production? Example: What effect does fertilizer have on snow peas?

6. Writing a Statement of the Problem What is the effect of chemicals? What is the effect of chemicals? What is the effect of chemicals on health? What is the effect of chemicals on health? What is the effect of vitamins on health? What is the effect of vitamins on health? What is the effect of Vitamin C on health? What is the effect of Vitamin C on health? What is the effect of Vitamin C on human health? What is the effect of Vitamin C on human health? What is the effect of Vitamin C on the occurrence of the common cold in humans? What is the effect of Vitamin C on the occurrence of the common cold in humans?

7. Research Find prior information about your problem (background information) Find prior information about your problem (background information) Make initial observations Make initial observations –Use your five senses Apply previous knowledge Apply previous knowledge –Make inferences Gather factual information Gather factual information –Use books, journals, computer, etc

8. Form a Hypothesis Predict what will happen Predict what will happen –Best guess or possible explanation –Determines a possible solution Write as “If…then” or ‘If…then…than’ statement (If = cause; Then = effect) Write as “If…then” or ‘If…then…than’ statement (If = cause; Then = effect) Must be testable Must be testable Includes two variables Includes two variables –Independent –Dependent

9. Independent Variables The variable that is different or being tested. The variable that is different or being tested. Also called the Manipulated Variable Also called the Manipulated Variable ‘Cause’ part of Cause and Effect ‘Cause’ part of Cause and Effect Graphed on the X axis Graphed on the X axis Example: IF fertilizer is used, THEN the plants will produce more pea pods THAN the plants without the fertilizer.

10. Dependent Variables The variable that responds to changes in the Independent Variable The variable that responds to changes in the Independent Variable Also called the Responding Variable Also called the Responding Variable ‘Effect’ part of Cause and Effect ‘Effect’ part of Cause and Effect Graphed on the Y axis Graphed on the Y axis Example: IF fertilizer is used, THEN the plants will produce more pea pods THAN the plants without the fertilizer.

11. Treatment # pea pods Fig. 1. Pea Plant pod production on pea plants with and without fertilizer. Independent Variable Dependent Variable

12. Form a Hypothesis - Examples Problem 1: What effect does fertilizer have on snow peas? Hypothesis 1: IF fertilizer is used, THEN the plants will produce more pea pods THAN the plants without the fertilizer. Problem 2: What is the effect of Vitamin C on the occurrence of the common cold in humans? Hypothesis 2: IF 500mg of Vitamin C is given daily, THEN it will prevent the common cold in humans.

13. Design an Experiment Establish at least two test groups Establish at least two test groups –Experimental-the independent variable is applied to this group –Control-comparison or normal group; no independent variable applied Provide a list of materials Provide a list of materials Develop a procedure Develop a procedure –Explains what is to be done and when

14. Test Groups Pea Plants Control group: Control group: Test or Experimental Group: Test or Experimental Group: Vitamin C Control group: Control group: Test or Experimental Group: Test or Experimental Group: Water Fertilizer Placebo (no vit. C) 500 mg Vitamin C daily

15. Controlled Variables (Constants) Factors that remain the same throughout the experiment Factors that remain the same throughout the experiment Are the same for both the control and experimental groups. Are the same for both the control and experimental groups. Don’t change Don’t change Includes everything except the independent variable Includes everything except the independent variable Pea Plants: water, light, temperature, etc Vitamin C: age, sex, weight, diet, etc

16. Test the Hypothesis Make sure all variables are controlled Make sure all variables are controlled Follow the procedure Follow the procedure Record your observations Record your observations Record any mistakes, accidents, weather, etc. that might affect the results Record any mistakes, accidents, weather, etc. that might affect the results The experiment provides evidence for or against the hypothesis

17. Collect Data Use logs, journals, tables and graphs Use logs, journals, tables and graphs Record all observations Record all observations –Include things you don’t think are important –Qualitative Data –Quantitative Data Include time, units, duration, # trials or sets, etc. Include time, units, duration, # trials or sets, etc. Be specific! Be specific!

18. Organize the Data Daily Log Daily Log Graphs Graphs –Continuous data –Discontinuous data Tables Tables –Repetitive data

19. DayDateTimeTemp Comments and Observations 15/14 9 am 99 Planted seed and placed in direct sunlight for 6 hours 2-1023 9 am Avg. 98 Sprouts are showing in both groups 1124 9 am 96 No discernable difference between groups 1225 9 am 95Same 1326 91 Same growth rate; approx. 6 in tall. 1427 9 am 99 Plants are growing full sized leaves Daily Log The Effect of Fertilizer on Pea Production – Daily Log

20. Graphs or Figures Visual representation Visual representation Shows relationships Shows relationships Title at the BOTTOM! Title at the BOTTOM! Includes: Includes: –Pictures (Figures) –Bar graphs Discontinuous data Discontinuous data –Line graphs Continuous data Continuous data –Pie charts

21. Discontinuous Data Sharp, dramatic differences Sharp, dramatic differences Either – Or, no blending Either – Or, no blendingExamples: –color –Grade –sex

22. Graphs or Figures Discontinuous Data Treatment # pea pods Fig. 1. Pea Plant pod production on pea plants with and without fertilizer. Independent Variable Dependent Variable Title

23. Continuous Data Regular, gradual changes Regular, gradual changes Shows linear relationships Shows linear relationshipsExamples: –Distance –Temperature –Time –Weight –Height –Age

24. Graphs or Figures- Continuous Data Time (Min.) Revolutions Fig. 1. Revolutions of an exercise wheel powered by a hamster over time. Independent Variable Dependent Variable Title

25. Tables Repetitive data Repetitive data Like elements read down Like elements read down –Compact and easy to read Title goes at the TOP! Title goes at the TOP! HeadingHeadingHeading Related data Table 1: How to correctly set up a table.

26. Tables FertilizerWater Group 1 1810 Group 2 21 8 Group31511 Group41210 Total6639 Average16.59.75 Table 1: The number of pea pods produced for each treatment per group of pea plants. Title

27. Draw Conclusions Analyze your data and summarize your findings. Is a judgment based on the results Is a judgment based on the results Can agree, disagree, or reveal nothing about the hypothesis Can agree, disagree, or reveal nothing about the hypothesis State potential flaws State potential flaws

28. Publish and/or Repeat Publish in a peer-reviewed journal Allows others to critique and test Allows others to critique and test Important research: Design different experiments to test the hypothesis or generate additional hypotheses. Design different experiments to test the hypothesis or generate additional hypotheses.