We can distinguish two viewpoints about the practice as ideal types. The viewpoint A is of the personalization of practice; the experience as knowledge source, the personality as main attribute of practitioner, and the skill as behaving mechanism. The viewpoint B is of the depersonalization of practice; the theoretical knowledge as knowledge source, the qualification as main attribute of practitioner, and the technique as behaving mechanism. These superficially opposing viewpoints need to be integrated or structured in terms of the competence-performance perspective in linguistics. In this article, by using of Popper's idea of the third world in "objective knowledge", Polany's idea of the tacit knowledge, Mauss' idea of the habitus, Bourdieu's idea of pratique, Ikuta's idea of " waza ", and Goldstein's idea of three variables in the style of social worker, we offerd the scheme of practice as following; (a) the competence is transformed into the performance through the medium of habitus, (b) the practice is transformed into habitus, and (c) the habitus is transformed into the instrumental form for the practice.
