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theory-in-use
One must treat theory-in-use as both a psychological certainty and an intellectual hypothesis.
Human beings hold two types of theories of action. There is the one that they espouse, which is usually expressed in the form of stated beliefs and values. Then there is the theory that they actually use; this can only be inferred from observing their actions.
People are unaware of the inconsistency between their espoused theories and their theories-in-use.
When people are asked how they would behave under certain circumstances, the answer they usually give is their espoused theory of action for that situation. This is the theory of action to which they give allegiance, and which, upon request, they communicate to others. However, the theory that actually governs their actions is their theory-in-use.