4. Human operators are really people

In human factors and human engineering, the term “human operator” is commonly used. As a dry technical term, it suggests a human component to a system that functions in a predictable and reliable way, like other hardware and software components. I wonder if the broad use of this term predisposes engineers to assume that the “operators”, once trained and qualified, can be treated analytically like any other system component.

So it’s worth remembering that human operators are actually people, and therefore subject to all the faults and frailties of any person. This includes surprise, stress, workload, divided or channeled attention, distraction, cognitive biases, jumping to conclusions, reacting instinctively, and many others. And human performance is ultimately the product of human behavior, which in turn is driven or shaped by an almost infinite set of influences. These include:

• personality characteristics
• culture
• experience
• all of the specific circumstances (environmental, system state, personal, etc.) present in any given situation.

In domains like aviation, the shear number of variables that can affect what people do in a specific situation is so large that it’s impractical to try to predict outcomes probabilistically. Since no amount of training turns people into machines, the human is always the most complex and least deterministic part of any non-autonomous system.