TItle from home page (viewed on June 14, 2005). "Summary File 3 (SF 3) contains data on social, economic and housing characteristics compiled from a sample of approximately 19 million housing units (about 1 in 6 households) that received the Census 2000 long-form questionnaire." "The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution."