Washington

The SF1 Supplement file was created for three reasons: (1) to provide users with urban/rural data at the block level (not available on the Summary File 1 State files [ICPSR #3194]), (2) to provide users and American FactFinder with a source for updating SF1 tables P2 and H2 with urban and rural summary counts for all SF1 state summary levels, and (3) to provide users with SF1 tables P2 and H2 for three summary levels (085, 090, and 100) that were not available prior to urban/rural delineation.

Summary File 4 (SF 4) from the United States 2000 Census contains the sample data, which is the information compiled from the questions asked of a sample of all people and housing units.

These Public Use Microdata Sample (PUMS) files contain records representing 1-percent samples of the occupied and vacant housing units in the United States and the people in the occupied units in 2000. Group quarters people also are included. The files contain individual weights for each person and housing unit, which when applied to the individual records, expand the sample to the relevant total.

These files were compiled from Census 2000 responses to the long-form (sample) questions about where people worked. The files present data at the county level for residents of the 50 states and the District of Columbia. The residence file shows the number of people who live in a county and the work destinations for the people who live in each county. The work file shows the origins of the people who work in each county.

Summary File 2 contains 100-percent United States decennial Census data, which is the information compiled from the questions asked of all people and about every housing unit. The Final National component of Summary File 2 describes the entire United States. Population items include sex, age, race, Hispanic or Latino origin, household relationship, and group quarters occupancy. Housing items include occupancy status, vacancy status, and tenure (owner-occupied or renter-occupied).

The numbers contained in this study are released pursuant to the order of the United States Court of Appeals for the Ninth Circuit in Carter v. Department of Commerce, 307 F.3d 1084. These numbers are not official Census 2000 counts. These numbers are estimates of the population based on a statistical adjustment method, utilizing sampling and modeling, applied to the official Census 2000 figures. The estimates utilized the results of the Accuracy and Coverage Evaluation (A.C.E.), a sample survey intended to measure net over- and undercounts in the census results.

Summary File 3 contains sample data, which is the information compiled from the questions asked of a sample of all people and housing units in the United States.

Summary File 2 contains 100-percent United States decennial Census data, which is the information compiled from the questions asked of all people and about every housing unit. Population items include sex, age, race, Hispanic or Latino origin, household relationship, and group quarters occupancy. Housing items include occupancy status, vacancy status, and tenure (owner-occupied or renter- occupied). The 100-percent data are presented in 36 population tables ("PCT") and 11 housing tables ("HCT") down to the census tract level.

Part of the Census 2000 geographic product series, Census Tract Relationship Files (CTRF) show how 1990 census tracts relate to 2000 census tracts. The files consist of one record for each 1990 census tract/2000 census tract spatial set. A spatial census tract set is defined as the area that is uniquely shared between a 1990 census tract and a 2000 census tract. The CTRF consist of sets of four files for each of the United States and territories. The purpose of these files is to assist users in determining the relationships between 1990 and 2000 census tracts.

This data collection contains four tables derived from the Census 2000 100-percent and sample data:Table DP-1. Profile of General Demographic CharacteristicsTable DP-2. Profile of Selected Social CharacteristicsTable DP-3. Profile of Selected Economic CharacteristicsTable DP-4. Profile of Selected Housing CharacteristicsThe 100-percent data were obtained from the questions asked of every person and housing unit enumerated in Census 2000, while the sample data were taken from the questions asked of a sample of persons and housing units.