2.1 Concept of Reflection
Rodgers(2002:842-866) characterized Dewey’s four criteria for reflection as follows：

Reflection
1．Is a meaning-making process that moves a learner from one experience into the next with deeper understanding of its relationships with and connections to other experiences and ideas．
2．Is a systematic, rigorous, disciplined way of thinking, with its roots in scientific inquiry．
3．Needs to happen in community, in interaction with others．
4．Requires attitudes that value the personal and intellectual growth of oneself and of others. Constructivist thinks that the students' learning is a process of constructing information. Students carry on machining, transforming and adjusting in order to gain knowledge. Reflection is the advanced stage of self-construction. It has great meanings for the enhancement of students’ self-driving power, critical thinking, creativeness, and other qualities.

Reflection or critical reflection refers to the behaviors or processes of memorizing, thinking and evaluating of some experiences. Reflection is different from the systematic and groundless habits of thinking, and it is a preliminary study of the problem, a review of assumptions and beliefs in a logical sequence, testing the established concepts and strategies, being verified for practice, focusing on finding a way to solve the problem more effectively.

2.2 Concept and Characteristics of Reflective Learning
It is generally believed that reflective learning is the way to enhance learners’ self-consciousness and learning abilities so as to carry out learning activities smoothly. Reflection itself is a kind of critical, reflective, and exploratory thinking activity. And reflective action refers to the discussion, thinking, evaluation and solution to the problems. It is the critical thinking based on the analysis of inpidual ego experience, monitoring and evaluation according to the standard of some of experience and behaviors.

Students in higher education should be responsible for their own process as independent learners. They must take notice of their own feedback and their thoughts of learning. Programs of study explicitly require learners to do this, but even if they don’t, they can benefit from developing reflective skills themselves. The process that learners develop reflective skills is just the process of reflective learning. Tu Rongbao(2000) defined reflective learning as “learners reversed thinking of the process of self study activities and the learning characteristics of the events involved in the process.” This definition has been affirmed by lots of educators.
Reflective learning has the following basic characteristics:

Exploration: Reflection is not only a "memory" or "review" of the existing psychological activities, but also the ones that  find the "problems" and "answer". That is, to explore the questions and answers in the activity of their experience, to reconstruct their own understanding, to activate the wisdom of the inpidual, and to produce other information under the interaction of all aspects. The soul of reflective learning is “ask questions - to explore the problem - to solve the problem”. So, exploration is the basic characteristics of it.

Autonomy: The process of reflective learning is the process to act automatically. It is powered by the rationality of the pursuit of their own learning, to carry out the conscious and active inquiry. Students are both actors and directors, the real master from the beginning. They get the experience by self-awareness, self-analysis and self-assessment. The reflective learning is “willing to learn” and “insisting on learning” established on the basis of students’ learning motivation and the persistence. So, reflective learning is strongly autonomous. 建构主义学习理论大学生英语学习反思能力培养策略(3):http://www.751com.cn/yingyu/lunwen_34385.html