Motivation has been differently defined from various perpectives of psychology, sociology and linguistics. Some psychologists defined motivation in terms of certain needs. Ausubel (1968) identified some main needs which help construct learner motivation (1) the need for stimulation, the need to be stimulated by the environment, by other people or by ideas, thoughts and feelings; (2) the need for knowledge, which is defined as the need for achievement (Good and Brophy, 1990), the need to process and internalize the results of exploration, manipulation, activity, and stimulation, to resolve contradiction, to search for solutions to problems and for self-consistent systems of knowlege; (3) finally, the need for ego enhancement, for the self to be known and to be accepted and approved by others.