ABSTRACT
Human factors as a discipline takes a very realist view. It lives in a world of real things, of facts and concrete observations. It presumes the existence of an external world in which phenomena occur that can be captured and described objectively. In this world there are errors and violations, and these errors and violations are quite real. The flight-deck observer from chapter 3, for example, would see that pilots do not arm the spoilers before landing and marks this up as an error or a procedural violation. The observer considers his observation quite true, and the error quite real.
