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Scientific Method Created by: Peg Kueberth

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Scientific Method Steps: Problem Research Hypothesis Experiment Data & analysis Conclusion An organized approach to designing controlled experiments.

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Problem What question do you want to answer?

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Research Whats already been studied, experimented, learned?

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Hypothesis Educated guess at the answer to the problem written as an, If then statement

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Experiment I.D. variables, list materials, plan/list steps to follow in performing the experiment

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Data & Analysis Report measurements in SI units, decide how to display data (tables/graphs), make calculations, record observations

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Conclusion Accept, reject or modify hypothesis Quote data decision is based upon Comment on validity & reliability Suggest changes &/or future experiments

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Match the step to its description. A.Decide to accept, reject or modify hypothesis B.Identify variables, design & perform experiment C.Find out what experiments other scientists have performed D.Question you want to answer E.Record results, perform calculations F.Educated guess at the answer to the problem 1.Research 2.Problem 3.Hypothesis 4.Experiment 5.Data & analysis 6.Conclusion

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Is the Experiment Valid? Validity = tests what it claims to test Is only 1 variable changed? Is the independent variable being tested in a way it would really be used? If no control gp., not valid

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Is the experiment reliable? Reliability = gives same results when repeated If not reliable, a 2 nd variable must have been changed (not controlled) Repeat experiment to show reliability

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A pet owner wants to know which brand of puppy food produces the healthiest puppies. So, she looks up studies comparing top brands of puppy foods. What step of the scientific method is this? Problem Hypothesis Research Experiment Data & Analysis Conclusion

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Juan wants to know whether cherry tomatoes or grape tomatoes will produce the most fruit. He thinks the cherry will but decides to plant 5 of each kind to find out. He makes sure they all get the same amount of sun, water & fertilizer. What is the problem? Do cherry tomatoes or grape tomatoes produce the most fruit?

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Juan wants to know whether cherry tomatoes or grape tomatoes will produce the most fruit. He thinks the cherry tomatoes will but decides to plant 5 of each kind to find out. He makes sure they all get the same amount of sun, water & fertilizer. What is the hypothesis? Cherry tomatoes will produce more fruit than grape tomatoes.

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Juan wants to know whether cherry tomatoes or grape tomatoes will produce the most fruit. He thinks the cherry tomatoes will but decides to plant 5 of each kind to find out. He makes sure they all get the same amount of sun, water & fertilizer. After 3 months, the grape tomatoes produced an average of 1.2 lbs. per plant while the cherries produced an average of 1 lb. each. What should be Juans conclusion? Reject hypothesis or plan to test again next year to see if there was something special about this years grape tomatoes.

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Variable that can change the results of an experiment Age Size Individual differences Nutrients pH FoodHealth Fertilizer Air pressure Oxygen Anything

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Independent variable What you are testing Dependent variable What you are measuring

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Identify the independent variable & dependent variable in the experiment: Does taking 1000mg of Vitamin C daily prevent the common cold?

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Identify the independent variable & dependent variable in the experiment: Does playing music while studying lower test scores?

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Identify the independent variable & dependent variable in the experiment: number of hours of light exposure on the rate of seed growth? What are the effects of the

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Controlled experiments have: 1.Experimental group 2.Control group

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In a controlled experiment: Experimental group Control group The & are treated exactly the same except

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Both groups Control group The group that gets the independent variable is the: Experimental group

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Identify the control & experimental groups in the following experiment: A new drug is being tested for its effectiveness in reducing tumor growth. Half the cancer patients being tested receive the real drug while the other half receive a placebo, a pill that looks the same but is only sugar. Which half is the control & which the experimental? Experimental group = Control group =

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How many variables should you change at 1 time in an experiment? A. Any number B. 3 C. 2 D. 1 If you change more than 1 variable, you wont know which 1 caused what you measured.

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When evaluating an experiment look for: Is there a control group? Is only 1 variable different between the experimental & control groups? Is the sample size large enough to control for individual differences?

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Match the term to its description. A.Group that gets the independent variable B.Group that does NOT get the independent variable C.ANY factor that can change the outcome of an experiment D.Factor you are testing (changing) E.Factor you are measuring 1.Experimental 2.Variable 3.Dependent variable 4.Independent variable 5.Control

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Bias is: Giving just 1 side of the story Trying to sway people to agree with you or think what you want them to think

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Bias in science may involve: Failing to report data unfavorable to desired conclusion Designing experiment to give desired results Designing graphs to influence interpretation No control group, small sample size, changing 2 variables at once

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Preventing bias in science: Giving a placebo (fake drug) to the control group when testing new drug Designing experiment to give honest results Designing graphs to accurately show data Control group, large sample size, changing only 1 variables at once Double-blind design when testing new drug (neither patients nor researcher knows who got real drug )

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Science Fair Topic Tips Does the topic interest you? Will it interest others (judges)? Is it an actual experiment (testing something)? --not a model or demonstration! Can you obtain needed materials easily & quickly? --consider sample size! Can you make actual measurements? Is it valid? --test what it claims to test! Write 3 topic choices, each as a question (problem) --hand it in ASAP only 1 person/team can do a particular topic