As the 2010 Census lifts off, the Census Bureau is drawing attention to a complex database that will be a key element of its campaign to achieve a complete and accurate count of the U.S. population.

The central challenge of the census is to count every resident of the United States, many of whom do not know about the census or could be reluctant to participate. Based on housing, demographic and socioeconomic variables correlated with poor response in previous censuses, the U.S. Census Bureau produced a score for every census tract in the nation that predicts how hard it will be to get an accurate count of its residents. Each census tract has about 4,000 people.

In an appearance at the Pew Research Center today, Census Bureau Director Robert Groves said the database has enabled his agency—along with partner groups trying to encourage a complete count—to zero in on neighborhoods where census-promotion efforts are most needed. Starting in late March, as Americans are mailing back their census forms, the bureau will put tract-level data on response rates on its website, he said.

Groves will be in Alaska next week to begin the 2010 Census in a remote native village. Most Americans will not be asked to participate until March, when their forms arrive in the mail with an April 1 due date. The first census results will be released in December.

The database is available on this Census 2010 toolkit page. Groves spoke at “Conducting Census 2010,” a forum co-sponsored by the center, the Washington Statistical Society and the DC-American Association of Public Opinion Research. More about the event will be posted soon.