Chapter 3

Examining Continuous Variables

Normality is a myth; there never was, and never will be, a normal distribution.

Roy Geary (“Testing for Normality”)1


Chapter 3 looks at ways of displaying individual continuous variables.

3.1 Introduction

A continuous variable can in theory take any value over its range. (In practice data for continuous variables are generally rounded to some level of measurement accuracy.) Many different plots have been suggested for displaying data distributions of continuous variables and they all have the same aim: to display the important features of the data. Some plots emphasise one feature over another, some are very specialised, some require more deciphering than others. Perhaps the reason there are so ...

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