1. Introduction It is generally acknowledged that reflective teaching and reflective practices play an important role in teacher education. Reflection is also an important part in teachers' professional behaviour and relevant in their professional development. Various authors have pointed out the usefulness and necessity of reflection. For example, Killeavy and Moloney (2010) highlighted the ability to reflect on practice as the basis for learning. In addition, personal experiences are important in the teachers' development today, and is one method that supports such development (Shoffner 2009); the ability to reflect evolves out of our experiences both as a professional and a person (Scanlan and Chernomas 1997). In many countries teacher education programmes operate with the notion that is a critically important characteristic of an effective teacher. In Estonia, the ability to reflect on teaching practice is also one of the standards for teaching. Although is key to the development of a professional teacher, several authors have indicated that it is not well defined and this can cause problems in understanding the meaning of (e.g. Kreber 2005, Maaranen and Krokfors 2007). Reflection, however, can be used more deliberately if we realize its meaning and impact on our personal and professional development (Scanlan and Chernomas 1997). In this paper, we initially examine the definition of and theories about because it is important to know how the process of works in practice. Secondly, we conducted an overview of certain instruments used to measure and examined their validity and reliability. The starting point for defining is usually problematic (Akbari et al. 2010), but historically, Dewey is acknowledged as one of the originators of the concept of in the twentieth century (Hatton and Smith 1995). In most articles dealing with reflective teaching, the roots of the term are traced back to John Dewey (1933). According to Dewey (1933:9), is active, persistent, and careful consideration of any belief or supposed form of knowledge in the light of the grounds that support it and the further conclusions to which it. Furthermore, needs communication to formulate experience (Dewey 1930). Scanlan and Chernomas (1997) assert that is a mental process that we all use in our everyday lives. However, can be further developed for specific professional purposes. If we can become more aware of what entails then we should be able to label more accurately the mental processes of and further develop other reflective skills for professional purposes. Gibbs (1988) argued that without reflecting, received experience may be forgotten or the learning potential lost. His model of contains six stages: description, feelings, evaluation, analysis, conclusion and action plan. Mezirow (1991: 104) claimed that reflection is the process of critically assessing the content, process, or premise(s) of our efforts to interpret and give meaning to an experience. It includes thoughtful action with or premise reflection. Premise leads to critical reflection--this means more fully developed perspectives on meaning. Reflective learning can be divided into confirmative or transformative learning. Transformative learning produces new or transformed meaning while focuses on premises. Therefore, does not only involve a simple awareness of our experiences. Non-reflective action may be habitual action that takes place outside of focal awareness or thoughtful action with higher cognitive processes (Mezirow 1991). Discussing the topic of may be based on other well-known theories. For example, the five-factor personality theory describes five basic personality factors (extroversion, agreeableness, conscientiousness, emotional stability, and intellect/autonomy) (Hendriks et al. …