1. The Scientific Method
An overview

2. What is Science? “Science” derived from Latin ‘to know’
Way of asking and answering questions
Seeking answers to questions about natural phenomena (we are therefore limited to what kinds of questions we ask)
Scientific thinking reduces emotional reactions

3. Forms of Scientific Inquiry
Discovery or Descriptive Science
Observation
Qualitative vs. Quantitative data

4. Types of Logic Inductive Reasoning
Derive generalizations based on specific observations

5. Types of Logic Inductive Reasoning Deductive Reasoning
Derive generalizations based on specific observations
Deductive Reasoning
- Specific predictions follow from general premise

6. Forms of Scientific Inquiry
Discovery or Descriptive Science
Observation
Qualitative vs. Quantitative data
Hypothesis-Based Science

7. Scientific Design
Scientific knowledge begins with an observation and a proposed explanation.
Explanation called a hypothesis
A hypothesis is testable and falsifiable
In science hypotheses are tested by using them to make predictions about how a particular system will behave

9. Theories and Natural Laws
Theory: a description of the world that covers a relatively large number of phenomena and has met many observational and experimental tests
Law of Nature: theory (or group of theories) that has been tested extensively and seems to apply everywhere in the universe-they become part of the conceptual framework of a particular field

10. Scientific Method in Action
We use the scientific method in everyday life
Example:
You got in your car to drive up here and turned the key but the car wouldn’t start (observation)

11. Scientific Method in Action
Example:
You got in your car to drive up here and turned the key but the car wouldn’t start (observation)
Hypothesis: There is something wrong with the car

12. Scientific Method in Action
Example:
You got in your car to drive up here and turned the key but the car wouldn’t start (observation)
Hypothesis: There is something wrong with the car
Predictions: battery dead, ignition problem,
out of gas

13. Scientific Method in Action
Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank

14. Scientific Method in Action
Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank
Analyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half full

15. Scientific Method in Action
Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank
Analyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half full
Draw conclusion: gauge inaccurate, out of gas

16. Important terms:
Independent (manipulated) variable: condition or event under study (choose 1) .Graphing-x axis
Dependent (responding) variable: condition that could change under the influence of the independent variable (measure this). Y-axis
Controlled variables: conditions which could effect the outcome of the experiment so they must be held constant between groups.

17. experimental group: group(s) subjected to the independent variable
control group: group not subjected to the independent variable, used as measuring stick
reproducibility: producing the same result consistently to verify result. It is therefore important to describe your experimental design in enough detail for others to perform the same experiment.

18. Example Hyp: King’s collar repels fleas
Pred: dogs wearing King’s collar will have fewer fleas than those without collar
IV: King’s collar DV: presence of fleas
CV’s: anything that might effect the number of fleas on the dogs
Can we think of some???

19. Experimental Design
Obtain 500 dogs of various breeds from local shelters. Have vet weed out the 200 dogs with the most fleas. Randomly assign individuals to 2 groups.
Board the dogs in identical environments and treat them the same except that one group gets to wear the King collar and the other group does not
After 2 wks. The dogs are examined by a vet for fleas.

20. Results: the dogs wearing the King collars were virtually free of fleas after the 2 wk period compared to the dogs without the collars which had about the same number of fleas as when the experiment began

21. Incorrect assumptions invalidate an experiment!
Assumptions: factors thought to be true for the investigation but have not been verified or controlled
Commonly accepted information
Thought to be held constant but not controlled
Factors beyond the investigators control because of technical or time considerations
Sometimes called confounding variables
Incorrect assumptions invalidate an experiment!