Diane Vaughan's recent Dead Reckoning: Air Traffic Control, System Effects, and Risk is an important contribution to the literature on safety in complex socio-technical systems. The book is an ethnographic study of the workspaces and the men and women who manage the flow of aircraft throughout US airspace. Her ethnographic work for this study was extensive and detailed. She is interested in arriving at a representation of air traffic control arrangements as a system, and she pays ample attention to the legal and regulatory arrangements embodied in the Federal Aviation Administration as the administrator of this system. As an organizational sociologist, she understands full well that "institutions matter" -- the institutions and organizations that have been created and reformed over time have specific characteristics that influence the behavior of the actors who work within the system, and influence in turn the effectiveness and safety of the system. But her central finding is that it is the situated actors who do their work in control towers and flight centers who are critical to the resilience and safety of the system. And what is most important about their characteristics of work is the embodied social cognition that they have achieved through training and experience. She uses the term "ethno-cognition" to refer to the extended system of concrete and embodied knowledge that is distributed across the corps of controllers in air traffic control centers and towers across the country.
Vaughan emphasizes the importance of “situated action” in the workings of a complex socio-technological system: “the dynamic between the system’s institutional environment, the organization as a socio-technical system, and the controllers’ material practices, interpretive work, and the meanings the work has for them” (p. 11). She sees this intellectual frame as a bridge between the concrete activities in a control tower and the meso-level arrangements and material infrastructure within which the work proceeds. This is where "micro" meets macro and meso in the air traffic control system.
The key point here is that the skilled air traffic controller is not just the master of an explicit set of protocols and procedures. He or she has gained a set of cognitive skills that are “embodied” rather than formally represented as a system of formal rules and facts. “Collectively, controllers’ cultural system of knowledge is a set of embodied repertoires – cognitive, physical, emotional, and material practices – that are learned and drawn upon to craft action from moment to moment in response to changing conditions. In constructing the act, structure, culture, and agency combine” (p. 122). Vaughan's own process of learning through this extended immersion sounds a great deal like Michael Polanyi’s description in Personal Knowledge of the acquisition of “tacit knowledge” by a beginning radiologist; she learned to “see” the sky in the way that a trained controller saw it. The controllers have mastered a huge set of tacit repertoires that permit them to understand and control the rapidly changing air spaces around them.
A special strength of the book is the detailed attention Vaughan gives to the historicity and contingency of institutions and organizations. Vaughan’s approach is deliberately “multi-level”, including government agencies, institutions, organizations, and individuals in their workplaces. Vaughan takes full account of the fact that institutions change over time as a result of the actions of a variety of actors, and changes in the institutional settings have consequences for the workings of embedded technological systems. She points out, moreover, that these changes are almost always “patch-work” changes, involving incremental efforts to fit new technologies or team practices into existing organizational forms. “Incrementally, problem-solving people and organizations inside the air traffic control system have developed strategies of resilience, reliability, and redundancy that provided perennial dynamic flexibility to the parts of the system structure, and they have improvised tools of repair to adjust innovations to local conditions, contributing to system persistence” (p. 9). Institutions and organizations change largely through processes of "social hacking" and adjustment, rather than wholesale redesign, and she finds that the small number of instances of efforts to fully redesign the system have failed.
Particularly valuable in Vaughan’s narrative is her fluid integration of processes and factors at the macro, meso, and micro levels. High-level features like economic pressures on airlines, budget constraints within the Federal government (e.g. delaying implementation of long-range radar in the air traffic control system; 83), and military imperatives on the movements of aircraft (83); meso-level features like the regulatory system for air traffic safety as it emerged and evolved; and micro-level features like the architecture of the workspaces of controllers over time and the practices and problem-solving abilities that were embodied in their work – all these levels are represented in almost every page of the book. And Vaughan points out that all of these processes have the potential of creating unanticipated system dysfunctions beyond their direct effects. Even the facts of the diffusion of high-speed commercial jets and the rise in military staffing demands during the Vietnam War had important and unanticipated system consequences for the air traffic control system.
Vaughan refers frequently to the causal role that “history” plays in complex technology systems like the air traffic control system. But she avoids the error of reification of “history” by carefully paraphrasing what this claim means to her: “History has a causal effect on the present only through the agency of multiple heterogeneous social actors and actions originating in different institutional and organizational locations and temporalities that intersect with a developing system and through its life course in unanticipated ways…. Causal explanations of historical events, institutions, and outcomes are best understood by storylike explanations that capture the sequential unfolding of events in and over time, revealing the interaction of structures and social actions that drive change” (p. 42). This clarification correctly disaggregates the causal powers of “history” into the actors, institutions, and processes whose influences over time have contributed to the current workings of the socio-technical system. Further, it provides a useful contribution to the literature on institutional change with its granular level of detail concerning the “career” of the air traffic control system over several decades. (Here she draws on the work of sociologists like Andrew Abbott on the role of temporality in social explanations.)
One illustration of Vaughan’s attention to historical details occurs in her account of the extended process of invention, design, test, and publicity undertaken by the Wright brothers. This narrative illustrates the multi-level influences that contributed to the establishment of a paradigm of heavier-than-air flight in the early decades of the twentieth century – individual innovation, networks of transmission of ideas, institutional context, and the authority and reputation of the magazine Scientific American (pp. 49-63). And, like Thomas Hughes' historical account of the development of electric power in the United States in Networks of Power, her account is fully attentive to the contingency and path-dependency of these processes. This material makes a genuine contribution to science and technology studies and to recent work in the history of technology.
Vaughan sounds a cautionary note about the safety and resilience of the air traffic system, and its (usually) excellent record of preventing mid-air and on-ground collisions among aircraft. She has argued persuasively throughout the book that these features of safety and resilience depend crucially on the well-trained and experienced controllers who observe and control the airspace. But she notes as well the perennial desire of both private businesses and government agencies to squeeze costs and "waste" out of complex processes. In the context of the air traffic control system, this has meant trying to reduce the number of controllers through "streamlined" processes and more extensive technologies. Her reaction to these impulses is clearly a negative one: reducing staff in air traffic control towers is a very good way of making unlikely events like mid-air collisions incrementally more likely; and that fact translates into an increasing likelihood of loss of life (and the business and government losses associated with major disasters). We should not look at reasonable staffing levels in control towers as a "wasteful" organizational practice.
(Here is an earlier post on "Expert Knowledge" that is relevant to Vaughan's findings; link.)