One of the most active fields of educational research in recent years has been the investigation of problem-solving performance. Two opposing views of current research -- one suggesting that there are more differences than similarities within different domains, and the other stating that there is great similarity -- lead to a variety of questions: * Is problem solving a single construct? * Are there aspects of problem-solving performance that are similar across a variety of content domains? * What problem-solving skills learned within one context can be expected to transfer to other domains? The purpose of this book is to serve as the basis for the productive exchange of information that will help to answer these questions -- by drawing together preliminary theoretical understandings, sparking debate and disagreement, raising new questions and directions, and perhaps developing new world views.