Definition(s):

“It is a conception of the family as a legally married couple sharing a household. The adult male is in paid employment; his earnings provide the economic basis of the family-household. The adult female may also earn an income, but her primary responsibility is to the care of the husband, household, and children.  Adult male and female may be parents (in whatever legal sense) of children also resident in the household” (Smith, 1993, p. 52).

Smith, D.E.  (1993). The standard North American family: SNAF as an ideological code.  Journal of Family Issues, 14(1), 50-65.