HROs focus on the science of safety. HROs include organizations that conduct air traffic control, nuclear reactors, the transport of hazard materials, health care systems, and prisons. The science of safety is concerned with predicting vulnerability for major system accidents. The complexity of HROs is a function of the number of interactions in a given system as well as how veiled and difficult they are to understand. Tightness in the coupling of the interactions is reflected in how fast cause and effect occurs in the system. In the past few decades, researchers have found that agencies which operate according to certain principles, i.e., HROs, prevent accidents and perform better during system accidents than agencies that do not operate according to HRO principles. In the book "Managing the Unexpected: Assuring High Performance in an Age of Complexity," Karl E. Weick and Kathleen M. Sutcliffe identify and elaborate upon five principles that they have found in varying degrees in all HROs. These principles have become a touchstone for some of the subsequent HRO research reported in the literature. The five HRO guiding principles pertain to preoccupation with failure, a reluctance to simplify, sensitivity to operations, commitment to resilience, and deference to expertise. This article discusses the rationale and features of each of these principles and how they can apply to the management of inmates and offenders supervised on probation or parole. 69 notes