The Field Guide

The Field Guide to Understanding Human Error

Author: Sidney Dekker


This book advocates a radical ‘New View‘ of human error, one which sees mishaps as ‘the symptom of deeper trouble’. This contrasts with the ‘Old View‘ which propounds the ‘bad apple theory’ in which practitioners who make mistakes are seen as ‘defective’ and are sanctioned. The ‘Old View’ is however prevalent because it serves to preserve the reputation of organisations, and it is reinforced by the practitioners who take ‘personal responsibility for the outcome of their actions’, something the book calls ‘the illusion of omnipotence’ (page 11).


The author, a professor of human factors and system safety, believes human error exists ‘…only as a convenient but misleading explanatory construct’ (page ix). He sees human errors as ‘…the other side of human expertise…’, and considers accidents to be ‘…structural by-products of a system’s normal functioning’ (page 17). The ‘New View’ argues that the unsafe trade-offs between safety and efficiency that characterise complex systems are responsible for errors. The book acknowledges the contribution of human factors and discusses several such as cognitive fixation, plan continuation, thematic vagabonding, tunnelling, regression, the keyhole problem, automation surprise, and procedural adaptations. It however maintains that when mishaps happen, the unfolding sequence of events must have made sense to the involved practitioners at the time. This ‘local rationality principle‘ takes into consideration ‘…the complexities, dilemmas, trade-offs and uncertainty’ that accompany most adverse events (page 13).

404 error message something went wrong. i a walsh on Flikr.
404 error message something went wrong. i a walsh on Flikr.

The author dedicates a major part of his book to the investigation of accidents. He criticises the old, retrospective, investigation approach which focuses on the individuals closest to the event (pages 21-22). This approach uses the ‘language of counterfactuals‘ such as ‘they could have’, ‘they shouldn’t have’, and ‘if only they had’ (page 39). The author says this ‘Old View’ attitude is the consequence of the hindsight bias which hinders investigators from exploring alternative or wider explanations of people’s behaviours (page 23).

The author disputes the concept of a primary or root cause for adverse events saying ‘…cause is not something you find…’ but ‘…something you construct (page 76); cause is ‘…simply the place where you stop looking any further’ (page 77). To fully understand the reasons for errors the author urges investigators to ‘…step into the past…’ (page 37); to adopt a perspective ‘…from the inside of the tunnel‘ (pages 26); to avoid cherry picking and micro-matching data (page 31); and to assume ‘the language of understanding and explanation’ (page 53).

In its discussion of the technical aspects of accident investigations, the book refers to human factors data, the nature and language of debriefing, conversation analysis, and the process of building a timeline. He discusses the concepts of ‘reconstruction of mindset‘, and ‘coupling behavior and situation’ (page 111), and discourages the use of alternative labels for human error such as complacency, non-compliance, loss of crew resource management (CRM), and loss of situational awareness (page 120). The author suggests how safety departments could help organisations address failings and create safer systems.” target=”_blank”>

The author on why things go wrong

The central theme of the New View is its systems approach to human error. This advocates the systemic model of accidents, as opposed to the ‘sequence-of-events’ and ‘epidemiological’ models. The systems approach looks beyond ‘the sharp end‘ and addresses the organisational policies generated at ‘the blunt end’ which predispose to errors (page 60). Such policies contribute to behaviours such goal conflicts, procedural drift, and normalization of deviance. The book argues that good systems appreciate failures as opportunities for organisational learning, ‘…a window through which they can see the true internal workings of the system that produced the incident or accident’ (page 61).


This book advocates a refreshing, even if slightly controversial, concept of human error. The author illustrates his arguments with several examples, typically from aviation, but the principles apply equally to healthcare. He points out that many human errors arise from policy decisions taken far removed from the sharp end. He sees mistakes as symptoms of systemic deficiencies and therefore important learning opportunities.

The author often makes his arguments repeatedly to emphasise the views he clearly feels passionate about. That passion shows throughout the book and often comes through as uncompromising. The issue of personal responsibility for errors is not as distinct as he makes it out to be, and some flexibility is required to strike a reasonable balance between individual culpability and organisational responsibility. His strong views may therefore restrict his audience.


The book is a very important contribution to the field of human error. Safety specialists stand to gain the most from the book’s insightful approach to investigating mishaps, but the information is beneficial to all healthcare practitioners. It helps to give a healthy and often contrary view of human error and I recommend it to all doctors.



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