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