tant part of census preparation. The exact set of questions has varied in the past, depending in part on legal and regulatory requirements on the collection of data, as has the mix of questions between the short and long forms. In the 2000 census, for instance, marital status was shifted to the census long form along with such questions regarding housing as number of rooms and amount spent on rent (see National Research Council, 2004:App. B). Once questionnaire content has been finalized, the actual questionnaires and mailing materials must be developed and tested (4). Even small changes on questionnaires can be consequential, and so the exact phrasing and layout for questions such as race and Hispanic origin are extensively debated. For 2000, the question on Hispanic origin was moved to immediately precede the race question and—for the first time—census respondents could choose to identify themselves as belonging to more than one racial category.

Critical choices then involve determining exactly which enumeration procedures (5) will be applied to which areas of the country. Most of the population—some 82 percent in 2000—lives in areas with predominantly city-style (street number and name) addresses, and so is assigned for enumeration via mail (questionnaires are sent by mail and are expected to be returned by mail). But mailout/mailback was just one of nine types of enumeration areas (TEAs) used in the 2000 census, with a variety of other methods being applied to count the remaining 18 percent of the population. Among these other options are update/leave, used in predominantly rural areas, in which enumerators drop off questionnaires at specific housing units and update address informa-