Metacognition is one of the buzz words in educational psychology, but it is not always clear what is meant by metacognition. Metacognition refers to higher order thinking that involves active control over the cognitive processes engaged in learning. Because metacognition plays a critical role in successful learning, it is important to study metacognitive activity and development to determine how students can be taught to apply their cognitive resources through metacognitive control. The term "metacognition" is most often associated with John Flavell (1979), who proposed that metacognition consists of both metacognitive knowledge and metacognitive experiences or regulation. Flavell further divides metacognitive knowledge into knowledge of person variables, task variables, and strategy variables. Most definitions of metacognition include both knowledge and strategy components. Most individuals of normal intelligence engage in metacognitive regulation when confronted with an effortful cognitive task, but some are more metacognitive than others. The most effective approaches to metacognitive instruction involve providing the learner with both knowledge of cognitive processes and strategies and experience or practice in using both cognitive and metacognitive strategies. The study of metacognition has important implications for instructional intervention. (Contains 16 references.) (SLD)