The Bureau goes to great lengths to develop a quality address list and maps,  working with the U.S. Scope and Methodology

Our objectives were to (1) review the adequacy of the Bureau’s operations  for locating migrant farm workers and their dwellings during the 2000  Census, and (2) identify how, if at all, the Bureau can improve those  operations for the next decennial census in 2010. The Bureau’s Listing Operations Addressed Some of the Barriers to Locating Migrant and Seasonal Farm Workers but Significant Challenges Remain

The Bureau used more than a dozen operations to help ensure a complete  and accurate address list. Although the operations were designed to locate  various types of dwellings, not population groups as a whole, if properly  implemented their design appears to have been adequate for identifying the  hidden living arrangements in which a number of migrant and seasonal  farm workers live. However, the operations were generally not as well  suited to overcoming language and other challenges associated with  locating these population groups. Overall, to the extent that they were properly implemented, the design of  the Bureau’s MAF-building operations appears to have been adequate for  identifying the hidden and unconventional dwellings in which many  migrant farm workers reside. However, most of these operations were not as well suited to overcoming  other challenges to locating migrant farm workers, such as a distrust of  outsiders and language and literacy issues. The Bureau appeared to do a  better job surmounting these challenges when it worked with local people  who knew where and how migrant farm workers lived, and could help  facilitate the Bureau’s access to those communities. Greater Use of Partnership Program and Innovative Practices Could Improve the Bureau’s Ability to Locate Migrant Farm Workers in the Future

Bureau officials told us that because it is relatively early in the decade, its  plans for locating and enumerating migrant farm workers are still being  developed. The Bureau partnered with state, local, and  tribal governments as well as religious, media, educational, and other  community organizations to improve participation in the 2000 Census  and to mobilize support for other operations. Make use of address information from local organizations. Use Census data strategically to help plan and manage address listing  operations. 2000 Census: Lessons Learned for Planning a More Cost-Effective 2010  Census.
Why GAO Did This Study

One of the U.S. Census Bureau's (Bureau) long-standing challenges has been counting migrant farm workers. Although the Bureau goes to great lengths to locate these individuals, its efforts are often hampered by the unconventional and hidden housing arrangements, distrust of outsiders, and language and literacy issues often associated with this population group. To help inform the planning for the 2010 Census, we were asked to review the adequacy of the Bureau's procedures for locating migrant farm workers and their dwellings during the 2000 Census, and the steps, if any, that the Bureau can take to improve those procedures.

What GAO Found

The Bureau used over a dozen operations to ensure a complete address list and accurate maps for the 2000 Census. To the extent that the operations were properly implemented, their design appears to have been adequate for identifying the hidden dwellings in which some migrant farm workers live, such as basement apartments. However, the operations were not as well suited to overcoming other difficulties associated with locating migrant farm workers such as language and literacy issues and a distrust of outsiders. These challenges were surmounted more effectively by relying on local advocacy groups and others in the community who knew where and how migrant farm workers lived, and could facilitate the Bureau's access to those areas. The Bureau's plans for the 2010 Census include an ambitious program to make its maps more accurate. However, additional steps will be needed. Local and regional census offices employed innovative practices during the 2000 Census that could help improve the Bureau's ability to locate migrant farm workers in 2010. They include partnering with state and local governments earlier in the decade when many address-listing operations take place (during the 2000 Census, the Bureau's partnership program was used largely to get people to participate in the Census, but these activities took place after the Bureau had completed most of its address list development activities). Other innovations included making use of address information from local advocacy groups to help find migrant farm workers, and using census and other demographic data strategically to plan operations and target resources to those areas with high numbers of migrant farm workers.