Information retrieval is a large and evolving topic. G. G. Chowdhury's Introduction to Modern Information Retrieval was first published in 1999 and now enters its third edition. The author approaches the topic from a library perspective, but endeavors to place library practice in the context of broader concerns in information retrieval and resource discovery generally. The book covers topics such as metadata formats, subject analysis and vocabulary control, abstracting and indexing, database technology, file organization, user requirements and interface design, natural language processing, digital libraries, web search engines and search engine optimization, evaluation of retrieval effectiveness, and experimental research.

One hardly need point out that many changes in information retrieval have taken place since the first edition of this book was published. This new edition includes new or expanded sections on developments in metadata standards, such as the Functional Requirements of Bibliographic Records (FRBR), automatic indexing, information retrieval on the web, XML markup and retrieval, and citation analysis.

The book draws heavily on the published literature. Each chapter has an introduction followed by an outline of important ideas in the area under discussion, often including summaries of significant published works. Each chapter concludes with a discussion and a lengthy list of references. This structure sometimes gives the book the feeling of an extended literature review rather than an independently argued viewpoint, but readers using this publication as a textbook will appreciate key contributions in the field being brought together and having both their significance and content succinctly explained. The discussion sections, seldom consisting of more than a single paragraph, summarize main themes covered in the chapter. The volume is furnished with a subject index.

The book's wide scope is its greatest strength. The author treats information retrieval not as an abstract problem of conceptual design but a practical one requiring an understanding of user needs as well as general design principles and specific technologies. The book serves its readers particularly well as a primer on the basic technical aspects of computerized information retrieval. The chapter on automatic indexing and file organization, for example, goes into considerable detail about alternative methods of term weighting and about how inverted files and alternative text retrieval structures work. The chapter on searching and retrieval includes not only information about query formulation and search strategies but also an explanation of vector processing. All of these topics are essential background for anyone working in this field.

I would have liked to see metadata issues analyzed in greater depth. Although the book covers traditional tools such as classification schemes and subject headings at some length, it does not fully articulate the rationale for recent developments, including FRBR and the proposed new cataloging code, Resource Description and Access (RDA). Missing is a deeper interest in exploring how metadata schemes and interface design interact in an effort to solve retrieval problems. For example, the chapter on cataloging and metadata contains screen shots of a faceted catalog display but relatively little analysis of how such displays utilize MARC, metadata originally designed for a different environment. The chapter on multimedia information retrieval outlines some high-level issues pertaining to music retrieval, but a closer study of something like the Indiana Variations2 project, briefly mentioned in the text, would have given readers a stronger sense of the specific challenges in this domain.

The question for any revision of an established textbook is how well it covers recent developments. Here I think the book meets with only qualified success. Recent years have seen a trend to decouple the discovery layer from the library management systems used to maintain the underlying metadata, a trend that comes as part of the effort to broaden the range of content that the discovery interface can encompass. This significant development is not specifically discussed in the book. The section in question instead focuses mainly on earlier approaches to the problem based on broadcast searching. Link resolution, an important technology in this type of environment, receives only a passing mention. These gaps are surprising given that the author devotes an entire chapter (chapter 22) to digital libraries, the types of aggregations they embody, and the issues heterogeneous aggregations pose for information retrieval. Proponents of the Semantic Web will be disappointed to find that their topic is not treated. Other topics of current interest in web retrieval, such as search engine optimization and metadata harvesting, are acknowledged, but receive only limited attention.

Some of the text should have received more careful proofreading. For example, the otherwise very valuable chapter on retrieval evaluation experiments cites the 2002 Text Retrieval Conference (TREC) on page 312 as being the most recent, but then goes on to mention the 2009 workshop on the next page. (The table of TREC tracks on page 314 has been updated as far as 2002, but no further, perhaps a reflection of the 2004 publication date of the book's second edition.) The book includes a handful of screen shots of end user interfaces, but at least in my review copy, the images (for example on pages 54–56) are often so blurred as to be almost unreadable. I hope this problem has been corrected in production copies.

Part of the difficulty of keeping up with developments in resource discovery is that the scope of the problem keeps changing. Chowdhury's book nevertheless deals expertly enough with a broad range of the basic issues to remain a valuable resource for students and practitioners. This new edition will extend the book's useful life.