The answers given by respondents to survey questions arise out of complex cognitive processes which involve more than strategies of recall or the interpretation of specific vocabulary used in questions. Respondents also employ a wide-ranging pattern of social knowledge surrounding the specific content area on which the survey touches. This social knowledge is possessed by every respondent, and is learned not only by direct experience, but by general exposure to cultural models. It may be though of as a set of expectations, both about what actually happens and what should happen, and implicit rules about when and to whom these expectations are applicable.