When Should a Decision Maker Ignore the Advice of a Decision Aid?

-This paper provides a simple probability analysis of the usefulness of decision aids that generate fallible advice . The main results are as fol­ lows. The usefulness of a decision aid depends heavily on the ability of the user to identify contexts in which the aid (or user unaided) is likely to be incorrect. Without this ability, attending to (i.e., consider, but not always ac­ cept) the advice of a decision aid is counterproductive -the decision maker would be better off either routinely accepting or routinely ignoring the aid's advice.