LEC 9 - Measures of Variability

LEC 9 - Measures of Variability - SHOWTIME! STATISTICAL...

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STATISTICAL TOOLS IN EVALUATION DESCRIPTIVE VALUES MEASURES OF VARIABILITY
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WHEN THE GRAPH OF THE SCORES IS A NORMAL CURVE, THE MODE, MEDIAN, AND MEAN ARE EQUAL THE MEAN IS THE MOST COMMON MEASURE OF CENTRAL TENDENCY WHEN THE SCORES ARE QUITE SKEWED OR THE DATA IS ORDINAL LACKING A COMMON INTERVAL, THE MEDIAN IS A BETTER MEASURE OF CENTRAL TENDENCY THE MODE IS USED ONLY WHEN THE MEAN OR MEDIAN CANNOT BE CALCULATED (E.G., NOMINAL DATA) OR WHEN THE ONLY INFORMATION WANTED IS THE MOT FREQUENT SCORE (E.G., MOST UNIFORM SIZE OR INJURY SITE) MEASURES OF CENTRAL TENDENCY
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MEASURES OF VARIABILITY DESCRIBES THE SET OF SCORES IN TERMS OF THEIR SPREAD, OR HETEROGENEITY • CONSIDER TWO GROUPS OF SCORES GROUP 1 = 9, 5, 1; GROUP 2 = 5, 6, 4 • BOTH HAVE A MEAN AND MEDIAN OF 5 BUT GROUP 2 HAS MUCH MORE HOMOGENEOUS OR SIMILAR SCORES THAN GROUP 1
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MEASURES OF VARIABILITY RANGE STANDARD DEVIATION VARIANCE
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RANGE EASIEST MEASURE OF VARIABILITY TO CALCULATE USED WHEN THE MEASURE OF
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LEC 9 - Measures of Variability - SHOWTIME! STATISTICAL...

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