In this paper, I will seek to raise critical questions about the adoption of PDA programs in academic libraries. In an era of shrinking budgets, PDA would seem to offer an efficient alternative to traditional collection development since it insures that the books purchased are the books used. In library science terms, PDA does away with the dilemma embodied by Trueswell’s well-known 80/20 rule, according to which a fraction of a library’s holdings account for the majority of its checkouts. As it has already become a commonplace to say in discussions of library policy, PDA supplants “just in case” with “just in time” purchasing. I will probe the assumptions embedded in the rhetoric of “just in time” and “just in case,” and ask whether these pithy formulae distort discussion of the two different approaches to collection-building from the start. I will explore the nuances of the conception of efficiency used to compare traditional collection development with PDA. If the 80/20 rule represents a problem for collection building – and as a preliminary it is crucial to question against what backdrop of expectation supported by what implicit statistical model it has been so understood -- does PDA solve it? Most importantly, what might be some of the practical outcomes of the implementation of a PDA program in academic libraries? To begin to get a handle of this last question, I will report on the examination of results of a PDA pilot program undertaken by the University of Oregon in concert with the Orbis-Cascade Alliance, offering a subject specialist’s insights into the books in the humanities acquired by the library through the program. Ultimately, I hope to suggest the competing ideas about the nature of libraries that underlie both PDA and the established approach to collecting from which it so radically departs.
