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Statistical Analysis


     * Organize data
     *  Infer from sample to population
     * Must be familiar with to read articles and interpret basic test information
    * Observations into numbers


Types of Data
             Nominal
             Ordinal
             Interval
             Ratio
             Used to determine the appropriate statistical analysis and type of data.


Nominal Data
             Place in categories
             Mutally exclusive
             Numbers must be exclusive
                  0 = males  1 = females
             Count the # of observations or percentage of observations


Ordinal Scale
             Ranks objects or individuals
             How much or how little
                  If A>B and B>C then A>C
             Greater than more than
             Direct comparison in terms of attribute
             Rank 1-2-3-4-5
             The distance can vary


Interval Scale
             More Precise
             Orders objects according to amount of attribute
             Equal intervals
             Equal differences
             Order & distance have meaning
             No true zero point


Ratio Scale
             Highest Level
             True zero point
             Equal intervals
             Physical and Motor Performance


Mode
             Represents Most Often
             18, 19, 20,21,21,22,23,24,
                  Mode = 21
             18,19,20,20,21,21,22,23,24
                  Mode = 20 & 21 Bimodal


Mode
             Not a stable measure
             Two modes from different populations are often different
             Seldom reported
             Used with Nominal Data


Median
              50% cases above and below
              10, 15,  20,  25, 30
              Median = 20
            Relates to middle. Must put numbers in order   (low to high or high to low).


Median
          50% cases above and below
          10, 11, 12, 13, 14, 15
          Median = 12.5
          Ordinal statistic based on rank order


MEAN = sum of score : N


Type Scores
             Mean = Interval or ratio
             Median = Ordinal Statistic
             Mode = Nominal
             Mean is more stable
                  Means will vary less than median or mode
                  More frequently used
                  Best indicator of combined performance of entire group
             Median = typical performance







Learning Objectives
             Know the following:
                  Types of data and how used (nominal, ordinal, interval, ratio)
                  Descriptive statistics (Measures of Central Tendency mean, median, mode)
                  How to calculate descriptive statistics
                  Advantages and disadvantages