Research Methods - Levels of Measurement

Levels of Measurement

Quantitative (numerical) data can be divided into different levels of measurement. There are three different levels of measurement: Nominal, Ordinal and Interval.

Nominal Data

This is data that falls into distinct categories, and frequencies are recorded in these categories. For example, counting the number of male and female teachers who drink tea and coffee at break time produces nominal data.

Ordinal Data

This is data in which the difference between data points are NOT equal. This includes rankings, rating and scores. For example, original data is produced when someone ranks their favourite three colours, noting that yellow is their favourite by a lot and the difference in preference for the colours ranking 2 and 3 is less significant.

Interval Data

This is data in which the differences between the data points ARE equal. This includes accurate scales of measurement such as time and distance. For example, interval data is produced when reaction time is measured in seconds.