In the past 15 years, educators and education researchers have increasingly emphasized the importance of cognitive processes for effective education in mathematics and science. This may be characterized as a shift away from the epistemology which treats knowledge as a compilation and categorization of facts toward the notion that knowledge is the conscious construction of meaning. This document reviews the literature dealing with metacognition in mathematics and science education. It focuses on three major identified variables: (1) "person variables," which are performance-relevant characteristics of the information processor; (2) "task variables," which are performance-relevant characteristics of the memory task or problem; and (3) "strategy variables," which are potential solution procedures. Each of these variables is explored and examples of problems are provided. (TW)