The first part of this paper intends to show the fundamental ideas behind the methodological achievements of Non--Symmetrical Data Analysis (NSDA) from a geometrical point of view. Then the paper focuses on some of the most recent extensions of NSDA which aim at studying multiple tables with comparative purposes by stressing their graphical aspects and giving insights on their interpretation tools. The methods presented in this part are then applied on a couple of data sets from the field of sensory analysis and water quality control. Finally, some of the most promising directions of further research in this field are outlined. S-Plus codes implement the four non--symmetrical comparative analyses presented in the paper.
ESPOSITO VINZI, V. (2002). Non-Symmetrical Comparative Analysis for Quality Control. In: Multivariate Total Quality Control: Foundation and Recent Advances. 1st ed. Heidelberg: Springer, pp. 191-220.