1.Brown thinks that metacognition includes two main parts: knowledge about cognition and regulation of cognition. The knowledge about cognition is the individual's knowledge about his own cognitive resources and the compatibility between learners and learning situations, that is, the individual's knowledge about his own cognitive ability and cognitive strategies. And what cognitive strategies should be used in what problem situations, how to best play his ability and other knowledge. Cognitive adjustment refers to the adjustment mechanism used by an active learner in the process of trying to solve problems, including planning, checking, monitoring and testing. These two parts have different properties. The knowledge about cognition is stable, conscious and expressible, and develops with the growth of individual age. Cognitive adjustment is unstable, usually unconscious, so it is difficult to express. It depends more on tasks and situations than on age. Even young children can use this adjustment process in some tasks, which are usually difficult for individuals, but not too difficult.

2.Flavell thinks that the two main components of metacognition are metacognitive knowledge and metacognitive experience. The so-called metacognitive knowledge refers to the knowledge fragments stored by individuals related to various tasks, goals, activities and experiences. Flavell believes that there are three main types of metacognitive knowledge: ① individual metacognitive knowledge, that is, individual knowledge about certain cognitive characteristics of oneself and others as cognitive processors. ② Metacognitive knowledge of tasks, that is, knowledge about the nature of information provided by cognitive tasks, requirements and purposes of tasks. (3) Metacognitive knowledge of strategies, that is, knowledge about strategies (cognitive strategies and metacognitive strategies) and their effective use. At the same time, fravel emphasized the interaction of these three kinds of knowledge. He believes that different individuals will make judgments on strategies according to specific cognitive tasks. The so-called metacognitive experience is a conscious cognitive experience or emotional experience that accompanies and is subordinate to intellectual activities. Fravel believes that there are many metacognitive experiences about the progress you have made or will make in a cognitive activity. Flavell believes that metacognitive knowledge and metacognitive experience interact in cognitive activities. On the one hand, metacognitive experience can lead to the addition, deletion or modification of metacognitive knowledge. Individuals discover the relationship between goals, strategies, metacognitive experience and tasks in cognitive activities, and then assimilate these findings into the existing metacognitive knowledge system. On the other hand, metacognitive knowledge can help individuals understand the significance of metacognitive experience and its influence on cognitive behavior. The relationship between them is also reflected in: sometimes they overlap, and some metacognitive experiences can be regarded as fragments of metacognitive knowledge entering consciousness.

3. Comparing and contrasting Brown's and Flavell's analysis of metacognitive structure, we can find that both of them think that metacognitive knowledge is one of the components of metacognition, but they have different views on the other component of metacognition. Another part of Brown is the regulation of cognition, but fravel didn't express it. The source of this difference lies in Flavell's analysis of metacognition as a static knowledge structure, while Brown's analysis of metacognition as both a knowledge entity and a dynamic process, that is, different analysis objects lead to different analysis results. In fact, from their definition of metacognition, it can be clearly seen that they all believe that metacognition includes not only knowledge about cognition, but also the regulation of cognition. Another component of fravel is metacognitive experience, which Brown didn't mention. In fact, Brown's adjustment skills, such as planning, checking, monitoring, modifying and evaluating, are closely related to the so-called metacognitive experience. The application of some skills will lead to metacognitive experience, while the application of some skills will be driven and guided by metacognitive experience. In other words, metacognitive experience is accompanied by the whole process of cognitive adjustment. Without metacognitive experience, cognitive adjustment is impossible. Therefore, combined with their views, we believe that metacognition consists of three parts: metacognitive knowledge, metacognitive experience and cognitive adjustment. That is to say, firstly, we think that metacognition has a dual state, which is both a static knowledge entity and a dynamic process. Therefore, cognitive regulation should be one of the basic components; Secondly, metacognitive experience and cognitive adjustment are essentially different. The former is a state of emotion or cognitive experience of cognitive subject, while the latter is a process (or skill). Therefore, metacognitive experience and cognitive adjustment should be separated as two relatively independent components. Although these three aspects are relatively independent, they are inseparable. On the one hand, cognitive adjustment is not only inspired and guided by metacognitive experience, but also based on metacognitive knowledge; On the other hand, every step of cognitive adjustment will make individuals have a new metacognitive experience and enrich and develop their own metacognitive knowledge. Moreover, metacognitive knowledge and metacognitive experience also interact (see Flavell's point of view above). These three aspects interact and circulate, and their dynamic and organic combination constitutes metacognition.