Unit 2 - Levels of measurement

What is meant by ‘levels of measurement’?

This refers to the way variables have been measured within a study.

How many levels of measurement are there?

Four - nominal, ordinal, interval and ratio data.

What is ‘nominal data’?

The level of measurement that show categories of data represented by frequencies. The sets have no relative numerical value, e.g. boys and girls.

What is ‘ordinal data’?

The level of measurement where data can be placed ranked or ordered into ascending or descending order but the intervals between data are not necessarily equal, e.g. times for first, second and third in a race.

What is ‘interval data’?

The level of measurement that has equal numerical intervals between scores but there is no true zero point, e.g. temperature.

What is ‘ratio data’?

The level of measurement that has equal intervals between scores and has a true or absolute zero point, e.g. speed (mph).

Which is the least sophisticated form of data?

Nominal data - it gives us a very basic picture where we don’t know anything about why this is the case.

Which is the most sophisticated form of data?

Ratio data - it gives us the most complex picture and allows us to compare data/ groups in a more sophisticated way.

What acronym should you use to remember the ranking of levels of measurement (least sophisticated —> most sophisticated)?

NOIR.