Beliefs play an important role in many aspects of teaching as well as in life. They are involved in helping individuals make sense of the world, influencing how new information is perceived, and whether it is accepted or rejected. Teachers' beliefs are a term usually used to refer to pedagogic beliefs or those beliefs of relevance to an individual's teaching (Borg 2001b). Teacher beliefs have been identified by Kagan (1992a) as tacit, often unconsciously held assumptions about students, about classrooms, and the academic material to be taught.The literature on teacher knowledge and beliefs from the primary and secondary levels has developed a number of terminological differences. Kagan (1990, p.456) highlighted this problem by noting: “Terms such as teacher cognition, self-reflection, knowledge and belief can be used to refer to different phenomena. Variation in the definition of a term can range from the superficial and idiosyncratic to the profound and theoretical”. The use of these varying terms makes it difficult to investigate in this area of teacher cognition. Pajares (1992) addressed this difficulty.Defining beliefs is at best a game of player's choice. They travel in disguise and often under alias-attitudes, values judgments, axioms, opinions, ideology, perceptions, conceptual systems, preconceptions, dispositions, implicit theories, explicit theories, personal theories, internal mental processes, action strategies, rules of practice, practical principals, perspectives, repertories of understanding, and social strategy, to name but a few that can be found in the literature. (p.309).Defining beliefs is not a very easy task. There is a “bewildering array of terms” as Clandinin and Connelly (1987, p. 487) put forward including teachers' teaching criteria, principles of practice, personal construct/theories/epistemologies, beliefs, perspectives, teachers' conceptions, personal knowledge, and practical knowledge.