Why Testing? Why Should It Cost You?

Abstract The authors of this essay consider the costs of the errors that occur in any kind of decision making. In a binary decision there are always two kinds of errors that can be made – saying ‘yes’ when you should have said ‘no’ (a false positive) or saying ‘no’ when you should have said ‘yes’ (a false negative). Choosing a decision-making strategy by simply adding up the number of each of two kinds of errors is only sensible if the costs of each of the two errors are equal. This is rarely the case. The authors explore these ideas in the context of college admission and testing.