A number of researchers have argued that the central function of
accurate metacognition is to provide people with optimal control
of their own learning (Koriat, 2000; Nelson & Dunlosky, 1991;
Nelson & Narens, 1990, 1994) by allowing them to allocate their
study time effectively. Benjamin, Bjork, and Schwartz (1998) put
it this way: “Poor self-monitoring capacity necessarily entails poor
selection and execution of relevant control processes: If you do not
know what you do not know, you cannot rectify your ignorance”
(p. 65). Nelson and Dunlosky (1991) argued, “The accuracy of
JOLs [judgments of learning] is critical because if the JOLs are
inaccurate, the allocation of subsequent study time will correspondingly
be less than optimal” (p. 267). Although these ideas
sound reasonable, at the present time, not only are there no data on
the relation between people’s metacognitions and their appropriate
allocation of study time, there are almost no data about the even
more fundamental question of what constitutes optimal allocation
of study time—a question of focal concern in this article. There
are, however, two theories.