The Scientific Method 7 Steps to a Logical Process

1. Identify the question What How Not “Why”

2. Background research …... Libraries Internet Experiments Researchers Interviews

3. State you hypothesis Educated guess Outcome Cause……leads to effect IF I do………then I expect………….

4. Design an experiment 1.Control 2.Experimental Group 3.One variable 4.Replicates

5. Collect data Measurable Machine Tool Color chart Factual

6. Analyze data Agreement in replicates Good Controls Graph trends

7. Communicate results Publish Conference Web page Design errors

1. Hypothesis versus Theory Hypothesis: Educated guess Outcome If I do….then I expect…… correct or incorrect Theory: Established idea Factual Experiments Data

Control versus Experimental groups Control: comparisons “Normal” condition Eliminates bias Experimental one variable one condition different from control more variables = more controls

Experimental Variables: Independent Variable: One condition that is changed from the control group Example: control = normal plant growth conditions independent variable= growth under no fertilizer Dependent Variable: the condition measured as a result of adding the independent variable Example: Measure growth in height as a result of no fertilizer

3 & 7.Data versus Opinion …... Data: Factual Measurable Replicates Opinion: Personal Inferences versus observations? bias

4. Types of Experimental Bias as opinion: Expectations Influences results Psychology experiments in design: Unequal treatment Poor Controls Plant experiments

Replicates of each group: Replicate= “Make an exact copy” Each group must have more than one setup for comparing results & verifying test conditions Minimum of 10 replicates

Scientific Data Must Be….. Measurable Quantifiable NOT opinion or judgment

7 Steps of the Scientific Method ? Different ? Precise ? Steps necessary? ? Most important