Interval

Interval data is the second highest level of data.

Properties

 * 1) Categories are mutually exclusive
 * 2) Ordinal data allows for rank order (1st, 2nd, 3rd etc.) of data
 * 3) Differences between units is uniform
 * 4) No zero starting point

Examples

 * Temperature (in Celsius)
 * Year (in A.D.)