The great number of information sources now available and the changing habits of web users, has led to the development of Web Scale Discovery Services (WSDS). The goal of these systems and techniques is to make catalogues, databases, institutional repositories, Open Access archives and other databases searchable and discoverable through a single point of access. The diffusion of such systems, and the connections between data disseminated by libraries and published by other institutions, poses a challenge to understanding discovery in the modern library. Web-Scale Discovery Services: Principles, Applications, Discovery Tools and Development Hypotheses summarizes and presents the state-of-the-art in WSDS. The title promotes a middle-way between finding the best tool for each articular need, and the search for the most reliable systems overall. The title identifies basic theoretical problems, as well as offering practical solutions for librarians. The volume offers a summary of ideas from around the world, giving a new perspective backed up by strong theory. Offering a vision for libraries, this book also allows archivists, museum specialists, computer scientists, commercial operators and interested users, to deepen their culture and information literacy.