only strategies to improve mail response (see Section 4-B), but also strategies to facilitate data capture and ensure an adequate work force for nonresponse follow-up, as discussed in Section 4-C. A concern with an aggressive strategy for completion of nonresponse follow-up is that it could have led to higher rates of missing and erroneous data. The evidence to date suggests that the use of new data capture procedures and technology and aggressive goals for enumerator recruitment and work completion were important innovations that had positive effects on timeliness while not impairing data quality.
Finding 4.2: Contracting for selected data operations, using improved technology for capturing the data on the questionnaires, and aggressively recruiting enumerators and implementing nonresponse follow-up were significant innovations in the 2000 census that contributed to the timely execution of the census.
The 2000 census used computers whenever possible to replace tasks that were previously performed in part by clerks or enumerators. Notably, questionnaires went directly to one of the four processing centers for data capture instead of being reviewed first by clerks in local census offices, as occurred for much of the workload in 1990. Editing and imputation of individual records to supply values for missing responses to specific questions or reconcile inconsistent answers were handled entirely by computer; there was no clerical review or effort to telephone or revisit households to obtain more content information as occurred in 1990 and previous censuses. Mail returns for households with more than six members and some other returns that appeared not to have not filled out the basic information for one or more members were followed up by telephone to collect the information for the missing members. However, in contrast to 1990, there was no attempt to collect missing items for already