at Santa Barbara, and University of Michigan among the academic leaders in the U.S.). Annual digital library conferences are also held in the U.S., Asia, and Europe, and new journals devoted to digital library research and development have been established. D-Lib Magazine 1 was founded in 1995, and the International Journal on Digital Libraries 2 was first published in 1997. Other books that have been published on the topic, while valuable, have primarily provided only high level descriptions of individual projects. Journal articles and conference papers are also available, but they usually provide detailed examination of single aspects of a digital library's design or, less frequently, an examination of the use and usefulness of a particular digital library. In contrast, Practical Digital Libraries provides a much-needed general introduction to the research and practice of digital libraries. The book addresses the broader social and technical implications of digital libraries, in addition to technical issues.
The goal of digital library research is to build working applications that provide direct user access to digitized content, such as the full text of books and journal articles, rather than access to bibliographic representations of content. In order to develop usable, working systems, research performed in many fields, including computer science, library science, information science, sociology, image recognition, human-computer interface design, and copyright and patent law, is relevant. Equally important are interdisciplinary studies of how users interact with materials in both traditional settings (where bibliographic tools aid in finding objects, but the objects must be physically retrieved by some other means) and in the emerging digital libraries. There are many practical research questions to be addressed. For example, are people reading the digital library content online or are they finding the articles and printing them before they read them? How is the