Spencer, D. (2009). Card sorting: Designing usable categories. Brooklyn, N.Y: Rosenfeld Media. 162 pages.

Spencer is a freelance information architect and interaction designer with extensive experience. This book is written for a general audience, but it will be of primary value for professionals learning how to conduct or improve card sorts. It is one of the only book-length resources available to focus on this subject. This book is primarily about card sorting but addresses the over-arching issue of how to design usable categories of information that other people will have to use and understand. Spencer begins with a clear explanation of what card sorting is, how it may or may not be the best option for the reader, and a short treatment of issues in categorization. The bulk of this book walks the reader through a detailed work-flow of how to think about, set-up, and administer a card sort.  It also includes several case studies and references to additional web content. Spencer is extremely knowledgeable and it is valuable to gain insight into her research process. The most exciting element of this book can be found in the final two chapters, which focus on how to analyze the card sorting data. The book provides a brief overview of various statistical methods and focuses on the three that Spencer uses the most often: k-means cluster analysis, hierarchical cluster analysis, and multidimensional scaling. This is a fantastic book useful for anyone interested in running a card sort. It provides very current, expert, and unique information.