 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