Descriptive statistics

Completion status: this resource is ~25% complete.

Two aspects of single variables (univariate) should be graphed and described:

1. Central tendency
2. Shape and spread of the data distribution

The choice of which graphs and descriptive statistics to use depends on the level of measurement and whether the variable is normally distributed.

Normally distributed variables

For normally distributed variables:

1. Descriptive statistics:
   1. Central tendency: mean, median, mode
   2. Spread: standard deviation, skewness and kurtosis, range, inter-quartile range, percentiles, minimum and maximum.
2. Graphs:
   1. histogram
   2. box plot

Non-normally distributed variables

For non-normally distributed variables:

1. Descriptive statistics:
   1. Central tendency: frequencies, percentages, mode
   2. Spread: range, inter-quartile range, percentiles, minimum and maximum
2. Graphs: bar chart, pie chart

See also

• Descriptives and graphing (Tutorial)
• Descriptives and graphing (Lecture)
• Graphing

External links

• Statistics glossary - Presenting data