response follow-up (4-C, see also Appendix C.3, C.5); one that facilitated timeliness but may have had mixed effects on data quality—namely, greater reliance on computers to treat missing data (4-D, see also Appendix C.5); and one that was sound in concept but not well-implemented—namely, the use of multiple sources to develop the Master Address File, or MAF (4-E, see also Appendix C.1). We do not assess an eighth major innovation in 2000, which was the expanded use of the Internet for release of data products to users; see http://factfinder.census.gov [12/12/03].
The final section in this chapter (4-F) assesses the problem-plagued operations for enumerating residents of group quarters. Sections 4-B through 4-F end with a summary of findings and recommendations for research and development for 2010.
The 2000 census, like censuses since 1970, was conducted primarily by delivering questionnaires to households and asking them to mail back a completed form. Procedures differed somewhat, depending on such factors as type of addresses in an area and accessibility; in all, there were nine types of enumeration areas in 2000 (see Box C.2 in Appendix C). The two largest types of enumeration areas in 2000—mailout/mailback and update/leave/mailback or update/leave—covered 99 percent of the household population; together, they constituted the mailback universe. The goal for this universe for the questionnaire delivery and mail return phase of the census was to deliver a questionnaire to every housing unit on the MAF and motivate people to fill it out and mail it back.
The Census Bureau expected that mail response would continue to decline, as it had from 1970 to 1990, due to broad social and economic changes that have made the population more difficult to enumerate. These changes include rising numbers of new immigrants, both those who are legally in the country and those who are not, who may be less willing to fill out a census form or who may not be able to complete a form because of language difficulties; increasing amounts of junk mail, which may increase the likelihood