According to Rogers (1959), who is one of the researches on self-concept, self-concept is a combination of organized and at the same time consistent perceptions and beliefs about self. On the other hand, Rosenberg (1989) defines self-concept as a collection of thoughts and ideas about self. Shavelson, Hubner and Stanton (1976) provides another point of view by taking common points of self-concept definitions into account, and they define self-concept as self-perception, created with the effects of past experiences and social environment. Franken (1994) states the importance of one's self-concept that there is a great deal of research which shows that the self-concept is, perhaps, the basis for all motivated behavior. It is the self-concept that gives rise to possible selves, and it is possible selves that create the motivation for behavior (Franken, 1994)