Data handling and analysis - Levels of measurement

What are the four levels of measurements

1. Nominal 2. Ordinal 3. Interval 4. Ratio

Interval data

Data measured using units of equal interval, which are known. Interval data can go into −ve values e.g. temperature

Ratio data

Data measured using units of equal interval, which are known. Ratio data has a true zero point e.g. length and time

Ordinal data

Measurements that can be put in an order, rank or position. The intervals between each rank are unknown

Nominal data

Simple frequency headcount found in discrete categories