Review by Shawn P. Curley, University of Minnesota Currently somewhat on the fringes of behavioral decision theory is the study of informal reasoning as a basis for understanding decision making. Such study oers promise for broadening our understanding of decision making beyond a predominantly black-box judgmental approach. As David Schum states in his Preface, logic and statistics often are not informative of the problems we encounter, and probabilists and artiยฎcial intelligence researchers have focused on algorithms and not the evidential foundations thereof. Schum's book brings together a program of research with which he has been involved for a number of years on the application of evidence for decision making. The book brings this work into a single, cohesive account.
David Schum lays down the challenge of developing a general theory of evidence as used in arriving at uncertain conclusions in everyday life. Such evidence is often varied and interconnected. For example, we may have evidence of the veracity of testimony about a piece of evidence that is connected to the hypothesis of interest through a chain of reasoning with multiple links; and, this may be just one of various lines of reasoning toward this hypothesis. It is a situation that Schum (p. 68) quotes Martin as describing as a wilderness of mirrors, an interconnected network of evidence that more or less accurately reยฏects reality. The book brings together Schum's reasoned eorts at, and compelling thoughts on, developing a theory to help us chart our way through this wilderness. He draws on research from a variety of areas, including philosophy, logic, probability, and semiotics.
A strong underpinning for the theory developed by Schum is the work of legal scholar John Henry Wigmore. Consistent with this legal foundation, the book focuses on trial evidence and courtroom situations throughout. Although extensions to other areas of potential applicability are noted, such extensions are not developed. On the positive side, examples are numerous and accessible even to one who is not versed in legal scholarship.