1. Scientific Method How Scientists Work Notes

2. How Scientists Work: Solving the Problems How Scientists Work: Solving the Problems MMMMuch of biology deals with solving problems TTTThese problems can be environmental, ecological, health related, etc. NNNNo matter what types of problems are being studied, scientists use the same problem-solving steps called… TTTThe Scientific Method

3. Then And Question Research Hypothesis Procedure/ Method Procedure/ Method Data Observations Conclusion What does the scientist want to learn more about? Gathering of information An “Educated” guess of an answer to the question Written and carefully followed step-by-step experiment designed to test the hypothesis Information collected during the experiment Written description of what was noticed during the experiment Was the hypothesis correct or incorrect? Next Then Next And Finally First Scientific Method An Overview

4. Scientific Method Scientific Method LLLLet’s break each of these steps down into their individual components: Ask Question Do Background Research Construct Hypothesis Test with an Experiment Analyze Results Draw Conclusion Think! Try Again Report Results Hypothesis is True Hypothesis is False or Partially True

5. 1. Observing 1. Observing  Make an observation  See something unusual  Frogs with incorrect number of legs! As we all know, frogs have four legs. What’s up with these froggies?

6. 2. Questioning 2. Questioning RRRRecognize, state or define the problem MMMMust be in the form of a question TTTThe obvious question is: WWWWhat is causing these deformities?

7. 3. Researching 3. Researching  Gather information related to the problem  Read, observe, measure, take samples, etc.  How frogs normally develop from eggs  The % of frogs with the deformities  Number of other species in the pond with deformities  Previous or new pollutants in the pond  Change in amount of UV (sunlight) exposure on eggs  Etc.

8. 4. Hypothesizing 4. Hypothesizing AAAA hypothesis is: AAAAn educated guess, trial answer, possible solution, prediction MMMMust be a statement MMMMust be testable or measurable IIIIs based on your research and previous experience

9. Hypothesizing Hypothesizing LLLList possible explanations (alternative hypotheses) based on your previous experience (what you already know); and on research you have done aaaall of the hypotheses must be testable (no demons allowed!)

10. Hypothesizing Hypothesizing SSSSome possible explanations (hypotheses) for the frog deformities: GGGG eeee nnnn eeee tttt iiii cccc m m m m uuuu tttt aaaa tttt iiii oooo nnnn CC hhhh eeee mmmm iiii cccc aaaa llll P P P P oooo llll llll uuuu tttt iiii oooo nnnn UU llll tttt rrrr aaaa vvvv iiii oooo llll eeee tttt R R R R aaaa dddd iiii aaaa tttt iiii oooo nnnn DD iiii ssss eeee aaaa ssss eeee ( ( ( ( vvvv iiii rrrr uuuu ssss o o o o rrrr p p p p aaaa rrrr aaaa ssss iiii tttt eeee o o o o rrrr............ ???? )))) LL oooo uuuu dddd R R R R oooo cccc kkkk & & & & R R R R oooo llll llll M M M M uuuu ssss iiii cccc AA llll iiii eeee nnnn ssss f f f f rrrr oooo mmmm o o o o uuuu tttt eeee rrrr s s s s pppp aaaa cccc eeee SS oooo mmmm eeee tttt hhhh iiii nnnn gggg e e e e llll ssss eeee

11.  Hypotheses' usually come in the form of “If …. then …..” statements  Ex:  Question: “How does the size of a wheel affect the speed of a HotWheels car?”  Hypothesis: “If the car has large wheels, then its speed will be slower.”

12. 5. Experimenting 5. Experimenting  Testing the hypothesis  Pick the hypothesis that makes the most sense and is easy to test  Then design a controlled experiment

13. Experimenting Experimenting  This is a real experiment that was carried out using the scientific method.

14. Control and Experimental Groups  used as a standard of comparison  the group containing the factor (variable) that has been changed Control group: Control group: Experimental group: Experimental group: (manipulated or independent variable)

15. Variables in an Experiment  Variables - Factors that can be changed  Controlled Variables - all the variables that remain constant  Independent Variable (manipulated variable) - factor in an experiment that a scientist purposely changes  Dependent Variable (aka Responding Variable) - the outcome or results, the factor in an experiment that may change because of the manipulated variable…. what a scientist wants to observe

16. Setting up a Controlled Experiment  In a controlled experiment, only one factor is changed at a time.  Independent variable: the factor that is deliberately changed  Dependent variable: the factor that the scientist wants to observe; it changes in response to the independent variable the factor that the scientist wants to observe; it changes in response to the independent variable

17. 6. Collect and Record Data Types of Recorded Data Types of Recorded Data  Quantitative - observations that involve measurements/numbers; i.e. 3 days, 12 maggots, 4 g, 13 sec, 8 liters  Qualitative - observations that do not involve numbers, are of a descriptive nature i.e. white maggots covered the meat, leaves were all wilting observations and measurements made in an experiment Data:

18.  Data is based on facts, not assumptions!  Fact: something that has actual existence; can be proven to be true  “School on a normal day at Cleveland HS starts at 7:57 am.”  Assumption: a notion taken for granted, usually based on some factual evidence  “At Nobel MS, we got out early every Tuesday so it’s the same at Cleveland HS.”

19. 7. Analyze the Data  Examine data tables, charts, and graphs  Examine experimental notes  Look for trends, patterns, and averages  What does the data show  Put your data into words

20. 8. Draw Conclusions CCCCollected data is analyzed and one comes up with a conclusion by deduction (deriving of a conclusion by reasoning) SSSSupport your conclusion with specific, numerical data. Accept or reject the hypothesis.

21. 9. Publishing Results o Ro Ro Ro Results of an experiment are useful only if they are made available to other scientists so they can verify results IIIIf no one knows about it, no one can prove or disprove it UUUUnless another scientist can reproduce the experiment with the same results, may become an inference (act of passing statistical sample data general conclusion) that may be incorrect AAAAnti-wrinkle creams WWWWeight loss drugs AAAAnti-aging pills

22. Why is Publication Necessary?  Which European is credited with “discovering” North America?  Christopher Columbus  Which European peoples really “discovered” North America?  Vikings  Why did Columbus get the credit?  Columbus told everyone who would listen, whereas the Vikings kept it secret

23. o A theory is a hypothesis that is supported by a large (humungous) body of scientific evidence  only after evidence is collected, tested by different individuals many times, and published can a hypothesis become a theory 10. Forming a Theory

24. Hypothesis vs. Theory vs. Law  What’s the difference between a hypothesis, a theory, and a scientific law?  hypothesis: educated guess that has no proof  “I am the best teacher at Cleveland High School.”  theory: hypothesis that is proven correct  “Smoking Causes Lung Cancer, Heart Disease, Emphysema, And May Complicate Pregnancy.”  scientific law: true and universal fact  “What goes up, must come down.”