Definitions: Means, Medians and Standard Deviations
Mean: The average of all the values of a variable such as age, weight-for-age z-score, income, or hemoglobin level.
Median: The middle value in a
distribution of values in a variable-- the value at which 50% of cases are above and 50%
are below.
If the median differs much from the mean value, then investigate the overall
distribution of values.
Standard Deviations: The standard
deviation indicates the variation in the group of measurements. When the values of a set
of observation lie close to the mean, the dispersion is less than when they are scattered
over a wide range. A difference in the standard
deviation of a variable when comparing different groups will indicate possible data
errors.