The Scientific Method Short Video: click on picture

Steps in the Scientific Method Observe and ask a Question Form a Hypothesis Controlled Experiment Collect & Analyze Data Draw Conclusion Publish Results

Steps in the Scientific Method Observe and ask a Question Form a Hypothesis

Hypotheses Educated Guess Observation Research Literature Hypotheses are tentative scientific explanations for a set of observations that can be tested Typically an IF…..THEN…. statement

Hypothesis Versus Theory Tested once to many times Tested many times & supported Data from one experiment Data from many experiments May be valid or invalid Shown to always be valid

Steps in the Scientific Method Observe and ask a Question Form a Hypothesis Controlled Experiment

Controlled Experiments Only one variable is changed Variable – factors that change Independent variable: manipulated Dependent variable: Responding Measured

Scientific Methodology Design controlled experiment Two test groups 1. Experimental group – Independent variable changed 2. Control group – Independent variable NOT changed

Situation 1 Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks. Control: Independent: Dependent: Conclusion:

Situation 2 Control: Independent: Dependent: Conclusion: Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes. Control: Independent: Dependent: Conclusion:

Steps in the Scientific Method Observe and ask a Question Form a Hypothesis Controlled Experiment Collect & Analyze Data

Data Data? Detailed record of experimental observations Types: Quantitative – counting/measuring Qualitative - descriptive

The Amount of Defective Cars Produced in Car Factories Graphs 1. Bar Graph The Amount of Defective Cars Produced in Car Factories

Graphs 2. Line Graph

Amount

Plotting Data

Steps in the Scientific Method Observe and ask a Question Form a Hypothesis Controlled Experiment Collect & Analyze Data Draw Conclusion Publish Results

Publish Results Primary Literature Peer reviewed

Identify variables as indicated: Redi’s experiment 1668 Flies from meat independent variable: dependent variable: