Facet analysis is an important theory in the fields of knowledge organization and information retrieval. It has been stated that it has dominated what has been termed "modern classification theory," and the Classification Research Group of the UK aimed to make it "the basis of all information retrieval." Yet the philosophical and methodological bases of facet analysis are poorly understood by the wider information community and the theory is not well documented. Facet Analysis provides a general overview of facet analysis as a formal methodology for building knowledge organization and search tools and as a general knowledge organization theory. The functions of faceted systems can be broadly categorized as: organizing content; building tools; designing interfaces; and empowering search, and examples of all of these are discussed. Coverage includes: a full statement of the principles and theory of faceted systems as developed by Ranganathan and the UK Classification Research Group, and that theory as it is understood today; discussion of the origin and development of analytico-synthetic classification and indexing tools, and of the use of facet analytical theory to underpin design and construction; discussion of different applications of facet analysis, not only in conventional information managements contexts (classification schemes and thesauri), but also in e-environments, both academic and commercial, and on the Web; and a survey of the work of a number of current writers and researchers in the facet analytical tradition, including those who work in the digital environment, for which a distinctive parallel strand of facet theory can be observed. This book will be useful reading for LIS students enrolled on classification, knowledge organization and information retrieval modules. It will also be of immediate use to practitioners concerned with information organization, management and retrieval, as well as software engineers, web designers, semantic web researchers and developers.