The principle of rationality is an idealized account of agency in which actors are assumed to choose actions that are adequate to their objective situation. In AI and decision theory contexts, it is useful as a simplifying model of behavior, while recognizing that real human and organizational decisions may depart from such rational assumptions.
(Also rationality principle.) A principle coined by Karl R. Popper in his Harvard Lecture of 1963, and published in his book Myth of Framework. It is related to what he called the 'logic of the situation' in an Economica article of 1944/1945, published later in his book The Poverty of Historicism. According to Popper's rationality principle, agents act in the most adequate way according to the objective situation. It is an idealized conception of human behavior which he used to drive his model of situational logic.