Academic librarians are challenged with development and maintenance of collections of research materials in various formats. Although it is assumed that they are monitoring the needs of their constituencies as a part of the collection management decision-making process, the literature reflects only a few studies that focus on direct solicitation of user opinions. This study included a 22-question survey sent to all faculty, staff, and graduate students in a cross-section of social science disciplines (anthropology, psychology, social work, and sociology) at one institution. Responses from 122 individuals (32.1% of faculty, 13.6% of graduate students, and 9.8% of staff) provide data about book and journal use that have informed collection development priorities and reveal shifting patterns of use in an increasingly hybrid (print and electronic) information environment. Results show that faculty and graduate students in all disciplines depend heavily on library collections and generally prefer to access materials online. When looking for books most respondents started from the library catalog, but those who indicated that the library was "not" important were more likely to search the Web and rely on colleagues to access materials, suggesting that social tagging might be an effective means of supporting resource discovery, especially if embedded in a scholarly community of practice. The relative importance of books and journals varies among (and within) disciplines and in accordance with the task at hand. Books are heavily used for teaching in all four disciplines, while journals are generally more important for research, especially among the more science-oriented specializations within anthropology and psychology. Even within these two disciplines, however, there are a number of scholars who rely heavily on books for research. Most respondents reported occasional use of interlibrary loan, more commonly for books than for journal articles, and this was generally considered to be an important and useful supplement to locally owned materials. (Contains 1 table, 8 figures, and 2 notes.)