, , , (Freud, 1958, . 278). , . , . , , . , , , - ( 15-17 ), (McCarthy, Brack, Lambert, Brack & Orr, 1966, p. 277). , , .
1900- , , (Gysbers & Guidance Program Field Writers, 1990) (. 1). , 1930- (Aubrey, 1979). (Brewer) , , . , , , 1970- 1980- (Gazda, 1989).
1960- . , 12 000 1958-1959- 40 000 1969-1970- (Shertzer & Stone, 1981). Occupational Outlook Handbook ( ), 63 000 1986 ; , , 3:1. . , 1980- , , NDEA, , , (Baker, 1992). 100 000, .