Facet theory was developed by Louis Guttman to help scientists to construct structural and other theories and test them empirically. It provides guidelines for analyzing and structuring research contents, for the formulation of hypotheses, designing the observations and provides concomitant procedures for processing empirical data. The main objective of facet theory is to facilitate cumulative knowledge and provide new possibilities for discovering laws in substantive domains of research. Concepts and techniques developed in facet theory, such as mapping sentences, regional hypotheses, faceted multidimensional scaling, unidimensional and multiple scaling have been found useful in a wide variety of research in the behavioral sciences, and have provided new insights in domains such as work and organizations, values and attitudes, intelligence, marketing, communications, education, health, social, clinical and organizational psychology. This book is intended to provide recent elaborations of issues in theory development and methodology as well as reports of research utilizing facet theory in a wide variety of domains. The articles in this volume, presented at the 10th International Facet Theory Conference in Roma, 10-13 July 2005, provide a good representation of the variety of research domains in which facet theory has been applied recently. The articles cover such diverse content domains as attitudes, stereotypes, and social representation; self and emotion; managerial, organizational, and work issues; and personal and social values. In addition, methodological problems relating to psychological assessment and to evaluation research have been discussed, as well as recent developments in data analysis.