The Scientific Method

1. The Scientific Method Unit 1: The Scientific Method Chapter 1-1 & 1-2

2. What is Science? • Science is a method of thinking about the natural world. • Biology is the scientific study of life.

3. Scientific Method • The scientific method is a procedure scientists use to seek answers to questions.

4. THE SCIENTIFIC METHOD PROBLEM HYPOTHESIS EXPERIMENT FORM A NEW HYPOTHESIS REPEAT THE WORK RECORD DATA & ANALYZE RESULTS CONCLUSION ACCEPT HYPOTHESIS REJECT HYPOTHESIS

5. 1. Identify a Problem • Observations are descriptions about the way something is or the way things happen • From these observations, a question is formed about why or how

6. Example: Identify a problem • Barney observes: • When I drink Coke, I burp a lot. • He asks Professor Frink: • Why does Coke cause burping?

7. Example: Identify a problem • Professor Frink explains: • You can do background research to help you know more • Look online about the physiology of burping

8. Wikipedia - not always 100% accurate, but a good start for background information carbon dioxide in drinks causes gas pressure to build in the stomach

9. 2. Create a Hypothesis • A Hypothesis is a prediction that may provide an answer to the question • The hypothesis must be “testable” • The hypothesis must be written in the form of an “If…, then…” statement

10. Example: Create a Hypothesis • If people drink Coke, then they will burp more. • Student example(s)…….

11. Hypothesis vs. Theory • Hypothesis: is an educated guess that can be tested and may or may not be true • Theory: a well-testedhypothesis that is supported by many types of observations • In science, theories are nearly facts • Ex. Theory of Evolution, Theory of Relativity, Cell Theory

12. 3. Controlled Experiment • Test the hypothesis • Procedure—the steps followed during an experiment • Well designed experiments have a control group and experimental group(s)

13. Subject Subjects

14. Control Group: all variables are kept the same (constant) • Used for comparison • Experimental Group: all the same variables except the one thing you are testing

15. The experimental group drink Coke. • The control group drink water. Independent Variable Control

16. Variables: anything that can influence the outcome of the experiment • Examples: age of subjects, health of subjects, having food or drinks before the experiment • Independent Variable: What you are testing • (The variable that is changed) • Dependent Variable: what is measured or observed • The variable that changes because of the independent variable

17. Example: Experiment • Independent Variable: type of beverage • Dependent Variable average number of burps Control Independent Variable

18. 4. Record Data & Analyze • Collect & record Data (information) • Qualitative data: descriptions • Quantitative data: numbers • Data can be recorded in a table • Analyze the data by graphing it • Bar graphs: show comparisons • Line graphs: show changes over time

19. Example: Recording Data Dependent Variable: what you measure Independent Variable Control

20. Average Number of Burps for Water vs. Coke Proper units Title • Analyze the Results: Bar Graph Y-axis = Dependent Variable Type of Beverage X-axis = Independent Variable Label

21. 5. Conclusions • The results tell whether the hypothesis was “accepted or rejected”

22. Example: Conclusion • Accept or reject the hypothesis? • ACCEPT! • Why? • There were more burps with Coke than with water based on the data and the results of the graph.

23. 6. Repeat the Work • When a hypothesis is supported by data from additional investigations, it is considered valid. • When a hypothesis is not supported, it means that we need to go back and ask new questions or identify sources of error in the experiment.

24. THE SCIENTIFIC METHOD FORM A NEW HYPOTHESIS REPEAT THE WORK ACCEPT HYPOTHESIS REJECT HYPOTHESIS

25. THE SCIENTIFIC METHOD PROBLEM HYPOTHESIS EXPERIMENT FORM A NEW HYPOTHESIS REPEAT THE WORK RECORD DATA & ANALYZE RESULTS CONCLUSION ACCEPT HYPOTHESIS REJECT HYPOTHESIS