ABSTRACT
This introduction presents an overview of key concepts covered in the subsequent chapters of this book. Multivariate statistics concerns the analysis of data in which several variables are measured on each of a series of individuals or subjects. The goal of the analysis is to examine the interrelationships among the variables: how they vary together or separately and what structure underlies them. These relationships are typically quite complex, and their study is made easier if one has a way to represent them graphically or pictorially. There are two complementary graphical representations, each of which contributes different insights. This chapter describes these two ways to view a set of multivariate data. The scatterplot is a very useful way to look at a set of data. It clearly shows the pattern of individual observations. Almost every multivariate analysis involves several of these plots. However, in one respect the very characteristic of the scatterplot that makes it useful also limits it.
