5[4]WEBB,N.J.,& CRIB,T.F.,Teaching process as a le[M].(Final Report,HE-000-882).Washington,DC:Department of Health,Education and Welfare.1967.10:116 ~ 129.
6[5]BABBIE,E.The Proctice of Social Science (8th Edition)[M].Belmont,CA:Wadsworth.1998.2:6 ~ 14.