Introduction

Abstract

The main motivation underlying this book consists in applications involving rankings, like for instance preferences stated by humans, recommendation of data analysis tools, stock trading support, information retrieval, meta-learning and recommender systems. For the evaluation of the different methods, the comparisons of different rankings by means of an appropriate, weighted, correlation coefficient is used. Some weighted correlation coefficients will be presented and analyzed in the book. We will also present some interesting applications like for instance in bioinformatics, principal component analysis, and clustering.