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Scientific Method. Ch 1 Notes. Observation vs. Inference. Observation is sensory input, without the brain’s influence upon the data. Inference is the brain’s natural process of drawing ideas & conclusions based upon incomplete sensory input. Scientific Method. O Observation H Hypothesis
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Scientific Method Ch 1 Notes
Observation vs. Inference • Observation is sensory input, without the brain’s influence upon the data. • Inference is the brain’s natural process of drawing ideas & conclusions based upon incomplete sensory input.
Scientific Method • O Observation • H Hypothesis • E Experiment • C Conclusion Developed by Galileo early 1600’s
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
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
Experimental Bias • Expectation defines results • If experimenter hypothesizes towards a result, more likely that (s)he will find these results • Motives?
Hypothesis Wording • If the independent variable is applied, Then the dependent variable will behave in a certain (quantified, if possible) way.
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
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.
Directions of the Compass Using unit circle, ascend from +x axis moving counterclockwise around the circle to get angle.
Unit Circle 90° W of N E 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
Going from # to Directional 90° Θ - 90 90 - Θ 135° 45° Θ 180 - Θ 0°, 360° 180° Θ - 180 360 - Θ 225° 315° 270 - Θ 270° Θ - 270
Going from Directional to # 90° α + 90 90 - α 135° 45° α 180 - α 0°, 360° 180° α + 180 360 - α 225° 315° 270 - α 270° α + 270
Examples: Unit Circle 30° E of N 15° N of W 32° E of S
Examples: Unit Circle 60° 155° 332°
Unit Circle Examples • A: 33 degrees = • B: 283 degrees = • C: 381 degrees = • D: 162 degrees =
Unit Circle Examples • E: 23° S of W = • F: 19° E of N = • G: 33° S of E = • H: 9° N of W =