ABSTRACT
This chapter is devoted to comparisons of properties and several examples of the four basic clustering models and algorithms. It begins with computational complexity. The chapter considers the geometric representation of searches for good clusters made by the four algorithms. This is followed by a long and important section on external cluster validity indices. For a serious treatment of computational complexity, interested readers are referred to Cormen et al. Rosen and Stinson both provide somewhat gentler but also technically correct developments of this important topic. The chapter provides a short review of the topics relevant to analysis of the algorithms presented for the Fantastic Four. Different operations such as max, min, sum, product, exponentiation, etc., take different amounts of time. But it is not practical to account for these differences even though they do affect the run time because exact accounting makes the analysis quite tedious while not improving its utility much at all.
