Extensible processing for archives and special collections: Reducing processing backlogs, by Daniel A. Santamaria, Chicago, American Library Association/Neal-Schuman, 2015, 235 pp., US$75.00 (US$67.50 ALA members) (soft cover), ISBN978-0-8389-1257-7 (available from Inbooks) This book examines extensible processing as applied to digital collections and repositories. Extensible processing addresses the problem of large processing backlogs through an interactive approach to archives. This approach involves creating a baseline level of access to all holdings in a repository and then conducting additional processing based on user demand and further assessment of collections. Extensible processing also deals with procedures to prevent backlogs occurring in the first place. The author, Daniel Santamaria, is a recipient of the Society of American Archivists 2013 Coker Award for innovative developments in archival description and has extensive experience in dealing with archival processes. Whilst acknowledging that backlogs are a difficult problem, the author believes that many backlogs are caused by rigid definitions of processing. The book looks at the key principles of providing baseline access to holdings, creating structured and standardised compliant descriptive data, minimising physical processing, managing collection material in aggregate groups and taking an iterative approach to processing. Emphasis is on principles and standards through taking a big picture approach. This involves looking at the collection as a whole, taking a top down approach first rather than leaping into processing one item at a time. It also involves creating a flexible structure for future processing rather than leaving it to chance. There is information on creating workflows and assessing collections. Developing a processing plan and appropriate metrics are also covered in later chapters. Issues such as privacy and security are not overlooked. As well as describing theory, the guide also discusses the practical application of the theory. The appendices contain details of eight case studies that apply extensible processing programmes. These consist of a range of North American institutions, from one-person shops to large institutions, including historical societies, a school, private collections, libraries, archives and consortia. Other appendices contain finding aid examples, sample work plans, and templates for a deed of gift and a takedown policy. There is an extensive list of related references for following up and a detailed index. The guide is designed for supervisors and managers of processing, as well as librarians and archivists who do the actual processing. It provides a useful approach for re-examining backlogs and the processing of material for collections and repositories. Anyone undertaking a digitisation programme, having issues with backlogs or with an interest in the area would find the book a worthwhile resource. Catherine Gilbert Parliament of Australia Library