Working memory is currently a 'hot' topic in cognitive psychology and neuroscience. Because of their radically different scopes and emphases, however, comparing different models and theories and understanding how they relate to one another has been a difficult task. This volume offers a much-needed forum for systematically comparing and contrasting existing models of working memory. It does so by asking each contributor to address the same comprehensive set of important theoretical questions on working memory. The answers to these questions provided in the volume elucidate the emerging general consensus on the nature of working memory among different theorists and crystallize incompatible theoretical claims that must be resolved in future research. As such, this volume serves not only as a milestone that documents the state-of-the-art in the field but also as a theoretical guidebook that will likely promote new lines of research and more precise and comprehensive models of working memory.