ABSTRACT

The concept of a set of relative frequencies, or a profile, is fundamental to correspondence analysis (referred to from now on by its abbreviation CA). Such sets, or vectors, of relative frequencies have special geometric features because the elements of each set add up to 1 (or 100%). In analysing a frequency table we can look at the relative frequencies for rows or for columns, called row or column profiles respectively. In this chapter we shall show how profiles can be depicted as points in a profile space, illustrating the concept in the special case when the profile consists of only three elements.