I kept in mind while reading this book the notion that currency is always a concern with print publications devoted to perpetually shifting and expanding topics such as metadata. Some minor dissociation is expected in this circumstance, and yet for a book published in 2007 I was surprised to come across one reference to the next revision of the Anglo-American Cataloguing Rules as “AACR3” (19) and another comment on the “forthcoming” PREMIS (Preservation Metadata: Implementation Strategies) project report (64). Compare these statements with events two years prior to the release of Metadata and Its Applications: the Joint Steering Committee for the Development of RDA essentially stopped development of AACR3 and rechristened the new cataloging code Resource Description and Access (RDA), whereas the PREMIS project saw publication of the Data Dictionary for Preservation Metadata together with the first version of its PREMIS Data Dictionary.1

This misalignment brings me to a major concern I have with this work. A surprising number of textual and layout errors appear; though for the most part minor in scope, they still summon frustration. These misprints take the form of missing letters from table headers, a mislabeled year in a citation, a pixelated image, and misdirected pointers to illustrations, among others. More serious oversights appear where a draft version of the text adjoins its final published form. Two adjacent paragraphs on page 124 effectively echo each other with regard to metadata crosswalks; the draft includes the erroneous term “crosswork.” In another instance, a lengthy quotation is set forth twice within a few lines of each other on page 57, with a modest discrepancy in content between them.

How these and other gross inaccuracies survived the editorial process I cannot say, but it bears the poor impression of a work carelessly run to press despite its seemingly lengthy gestation period. (For the record, I base this review on the first printing of the text.)

But, beneath these problems, I find a worthy effort by Liu to provide a wealth of information on digital library metadata. Sifting through a myriad of source material to forge a generalist text on this topic is a notable feat. Nevertheless, from another editorial sweep through the text would emerge a better work and a commendable adjunct, if not successor, to the metadata guide I cut my teeth on: the now five-year-old Metadata Fundamentals for All Librarians by Priscilla Caplan.²

The half-page summary Jia Liu devotes to the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) finds full expression in Timothy W. Cole and Muriel Foulonneau’s Using the Open Archives Initiative Protocol for Metadata Harvesting (hereafter Using the OAI-PMH). Their work is a rich and at times densely written examination of the protocol from historical, theoretical, and practicable perspectives.

OAI-PMH is a technological convention by which descriptive metadata for digital documents available on the World Wide Web is read and gathered (harvested) through automated means by data-collecting organizations, who in turn compile this information into large pools and make it available to the public for searching—in effect, a fashioning of union catalogs of digital library resources. The preceding statement is a fundamental definition and reflects the extent of my knowledge regarding the protocol when I received Using the OAI-PMH for review. This turned out to be a fortuitous happenstance, for the authors shaped their work with the student in mind. Like Liu’s Metadata and Its Applications, Cole and Foulonneau build on their themes incrementally; moreover, to test the reader’s grasp of the material, they cap each chapter with a series of discussion questions and suggested exercises. The authors explicitly aim their primer at those with prior knowledge of metadata, traditional library cataloging, and intermediate computer skills. In this light, Using the OAI-PMH is best suited to graduate students in advanced library systems or higher-level metadata courses. Yet the non-scholastic individual also can gain much from the reading whether through self-study or professional development opportunities.

After defining OAI-PMH and establishing the background for the development of the protocol in the first part of the work, including demystifying the notion that OAI-PMH employs only unqualified Dublin Core as a vehicle for metadata exchange, the authors set upon a studied trek through various technical matters in part 2, “Protocol Implementation.” One such topic of exploration is the protocol-driven content of the metadata shared between its creators (whom Cole and Foulonneau call “data providers,” like digital libraries) and those that harvest the metadata (“service providers”). Helped along by the authors’ cogent, though at times challenging, presentation, this section brought to light many of the details missing in my loose notion of what defines the OAI-PMH.

Chapter 7, “Post-Harvest Metadata Normalization and Augmentation,” and chapter 8, “Using Aggregated Metadata to Build Digital Library Services,” characterize not only the user-centric end—”services that address user and institutional needs” (162)—that justifies the metadata-sharing means described in the previous chapters, but stress as well the establishment of clear communication between the metadata providers and the harvesting agents. The authors point out that for OAI-PMH to work most effectively, each party must understand and acknowledge the motivations and processes of the other beyond the mere mechanical exchange of metadata. These collaborative activities include the recognition of collection development policies, encoding practices, and the correction, enhancement, and normalization of shared metadata. One outcome from this understanding is richer, more complex metadata that Cole and Foulonneau see as fueling the next generation of resource sharing projects and protocols; this future they summarize in their final chapter, “Concluding Thoughts.”

In sum, Using the OAI-PMH is an excellent introduction to this most popular form of metadata exchange and I believe a suitable handbook for practitioners in the digital library and data harvesting fields.

I end with a final word on back matter. Metadata and Its Applications and Using the OAI-PMH provide end-of-chapter citations, many of which point to online resources; the former also incorporates a culminating comprehensive bibliography. Reflecting the generous amount of information all three authors present, the indexes in both texts are quite detailed, though I did discover an irregularity in Liu’s work, namely, references to AACR2 and AACR3 as the second and third volumes, respectively, of the Anglo-American Cataloguing Rules rather than as editions of the same. Using the OAI-PMH is ostensibly a textbook, and in that capacity I am of the opinion that it would benefit the reader had the authors included a glossary of most or all of the highlighted terms present throughout the text.