Reference service, the idea that librarians provide direct assistance to users, has been a central function of libraries for over a century. Today's libraries are even more complex and intimidating to new users than libraries of the past, and the technical and social contexts in which users experience their library's resources add to this complexity. The availability of a friendly librarian who helps users find materials, search for information on a topic, interpret citations, identify quality information, and format bibliographies has become a standard component of what libraries do. However, changes in technologies, economics, and user populations are causing many libraries to question the need and function of traditional reference services. This book examines how library services meet user needs in the twenty-first century. Many libraries are asking key questions about reference services, such as: Should librarians be on call waiting for users or out in the community promoting the library? Should we assign staff to help users one-on-one or is it more effective to assign them to build and use tools to teach users how to find and evaluate information? Will we continue to purchase commercial reference sources or just use Wikipedia and other free resources on the web? With the proliferation of information available today, how can we help users evaluate search results and select the best resources that they can find? And how do we evaluate the effectiveness of reference services? Through contributions from the leading scholars and practitioners in the field, this volume addresses such issues and how they affect practices in public and academic libraries. In addition, it presents perspectives from the publishing community and the creators of discovery tools. Each section is enhanced by short case studies that highlight real-world practices and experiences.