2.1.1 Definition of Metacognition

The term “metacognition” was first put forwarded by J.H. Flavell (1976), the famous American psychologist, in the late 1970s. A more specific definition of metacognition was also given by Flavell, that is “Metacognition refers to learners’ knowledge about their own cognitive process and product and other things related to them”. What’s more, Flavell also classified metacognition into three aspects: metacognitive knowledge, experience and strategies (1979). Metacognitive knowledge can help learners to understand the reading material easier and better, while metacognitive experience helps learners to choose appropriate learning strategies. The three aspects of metacognition are linked closely in learning process.

With the further study of metacognition, a large number of researchers put forwarded many different views to define the concept of metacognition. Baker and Brown (1984) pide the definition of metacognition as two parts: metacognitive knowledge and metacognitive monitoring. One is one's knowledge about his cognitive capability and actual cognitive tasks, the other one is metacognitive monitoring. According to Weinstein and Mayer (1986), metacognition is the inpiduals’ knowledge about their cognitive process, as well as their abilities to control these processes by planning, implementing, monitoring and modifying them as a function of learning products and feedback.

From definitions mentioned above, we can conclude that metacognition is mainly comprized by metacognitive knowledge and metacognitive strategies, the former is one's knowledge about thinking process, and the latter is how to apply these metacognitive knowledge to solve problems or monitor cognitive activities.

2.1.2 Definition of Metacognitive strategy

Learning strategies are the specific actions taken by the learners in language learning. And the classification of learning strategies by O’Malley & Chamot (1990) is most representative, namely, metacognitive strategies, cognitive strategies, social and affective strategies. And metacognitive strategies focuses on processing the information input in the brain.

As for the definition of metacognitive strategy, Cohen (2000) thought that metacognitive strategy is an behavior before the language learning plan, monitoring a plan and evaluating the language learning. O’Malley & Chamot (1990) defined that metacognitive strategy includes planning, monitoring, evaluation and the higher order execution techniques in learning processes. They also pointed out that metacognitive strategies utilize cognitive knowledge and construct all attempts to regulate language through planning, monitoring, and evaluation. Meanwhile, Anderson (2003) states that various metacognitive skills will be beneficial for learners in the foreign language learning, following steps of making preparation for learning, choosing proper strategies, having supervision of strategy use, making regulations and making assessment of results.