Book excerpt: Kazdin's text is a notable contrast to the quantitative methodology approach that pervades the biological and social sciences. The methodology in Single-Case Reasearch Designs focuses on a widely applicable methodology for evaluating interventions, such as treatment, or psychotherapy, using applied behavior anlaysis. However, this revision aims to encompass a broader range of research areas that utilize single-case designs. The text will convey the pertinence of this research methodology to disciplines ranging from psychology and medicine to business and industry. The first edition of this book, which was published in 1982, still sells a steady amount of copies today. The fact that professors continue to use the first edition of this book more than twenty years after it was published is a testament to the quality of information, organization, and narrative throughout the text. The possibility of a revision has professors excited that they can expose their students toa well-written, clear, and updated text that will reflect the current status of single-case research.