Accident investigation and risk assessment have always focused on the human factor, particularly human error. This bias towards the study of performance failures leads to the assumption that there is little to be gained from studying failure and success together. Hollnagel, professor and industrial safety chair at MINES ParisTech, proves this assumption false through analysis of how people at work adjust what they do to match conditions. He proposes that this efficiency-thoroughness trade-off (ETTO) may lead to adverse outcomes, but that it leads to the same processes that produce successes. The author hopes that the ETTO Principle will remove the need for specialized theories and models of failure and human error, and offer a viable basis for effective approaches to both reactive and proactive safety management. In order to be accessible to a broad readership, the book is not written in the style of an academic text. However, each chapter concludes with a short annotated bibliography. Annotation ©2009 Book News, Inc., Portland, OR (booknews.com)