Descriptive Statistics
Measures of Central Tendency
Mean, Median and Mode
Mean (the average)
Sum all the observations and divide with the number of observations
(the best measure for continuous data that are normally distributed)
Median (the middle value)
Arrange in order first and find the middle/half value; the mid-point or 50th percentile
(used for ordinal data or continuous data that are highly skewed)
Mode (the most frequent value)
Arrange in order first, and locate the most frequent value of a dataset
(used for nominal data or describing the frequency or proportion of subjects in each category)
Range
the numerical distance between the highest value and the lowest.
Measures of Dispersion