Scientific Method

1
Scientific Method

• Ch 1 Notes

2
Observation vs. Inference

• Observation is sensory input, without the brains
  influence upon the data.
• Inference is the brains natural process of
  drawing ideas conclusions based upon incomplete
  sensory input.

3
Scientific Method

• O Observation
• H Hypothesis
• E Experiment
• C Conclusion
• Developed by Galileo early 1600s

4
Independent Variable

• Amount of this is manipulated by experimenter
• Control group does not receive I.V.
• Experimental group receives I.V., sometimes in
  varied amounts
• Belongs on x-axis of graphs

5
Dependent Variable

• Performance variable
• Compare/contrast D.V. performance of experimental
  and control group to confirm or reject hypothesis
• Belongs on y-axis of graph

6
Experimental Bias

• Expectation defines results
• If experimenter hypothesizes towards a result,
  more likely that (s)he will find these results
• Motives?

7
Hypothesis Wording

• If the independent variable is applied, Then the
  dependent variable will behave in a certain way.

8
Blind Experiments

• Used in situations where test subjects may change
  their performance if they know they are part of
  an experiment.
• Humans or sometimes animals
• Subjects not told whether they are a member of
  the experimental or control group.
• Avoids placebo effect (30-40 in medical field)
  in exp. group

9
Double-Blind Experiments

• Used to make sure that scientist bias does not
  affect the data collection of an experiment
• Neither the experimenters nor the test subjects
  know whether subjects are members of the
  experimental or control group till after study is
  over.

10
Directions of the Compass

• Using unit circle, ascend from x axis moving
  counterclockwise around the circle to get angle.

11
Unit Circle
90
E of N
W of N
45
135
N of E
N of W
0, 360
180
S of W
S of E
225
315
W of S
270
E of S
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Unit Circle Examples

• A 33 degrees
• B 283 degrees
• C 381 degrees
• D 162 degrees

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Unit Circle Examples

• E 23 S of W
• F 19 E of N
• G 33 S of E
• H 9 N of W