1. Introduction

Knowing the level of measurement you are dealing with is important because it helps you to decide what arithmetic and statistical operations you can carry out on the values that have been assigned.

A spreadsheet package like Excel will allow you to perform all sorts of complex calculations on tables of data – but the results you get may be meaningless if you don’t understand which operations are permissible for each level. For instance, you can assign 1 to males and 2 to females, but if you add up all the values, the total will not help you!