This report presents the results of the 2010 Census Coverage Measurement Initial Housing Unit Independent Listing, Matching, and Followup Operations. The results are from an operational standpoint and are not the final Census Coverage Measurement estimates of coverage. These Census Coverage Measurement Operations built the address list later used for the Census Coverage Measurement Person and Final Housing Unit operations and provided initial data for housing unit estimation. The 2010 Census Coverage Measurement survey operations were conducted in the survey sample areas in the United States, including Puerto Rico, but excluding Remote Alaska. The only living quarters in scope for the survey operations were housing units; that is, group quarters were excluded. There are four components to the Census Coverage Measurement Initial Housing Unit Independent Listing, Matching, and Followup Operations – Independent Listing, Initial Housing Unit Computer Matching, Initial Housing Unit Clerical Matching, and Initial Housing Unit Followup.

During Independent Listing, conducted in the United States and Puerto Rico in the fall of 2009, listers canvassed each block cluster assigned, which consists of one or more contiguous census blocks, and independently listed all housing units and units that could become housing units by Census Coverage Measurement Person Interview Day in August of 2010. Listers also map spotted each unit they listed and updated maps by adding and deleting streets on paper maps, when necessary. Once the listing was complete, Dependent Quality Control listers recanvassed a sample of addresses in each block cluster during the Dependent Quality Control operation to check the listers’ work. The data collected were keyed at the National Processing Center in Indiana.

In September 2009, the Census Bureau launched an initiative to reduce nonsampling error in the Census Coverage Measurement program. In order to do so, the sample size for operations after the Independent Listing was decreased and resulting surplus funds from the reduced workload were put towards approaches to reduce the nonsampling error. Independent Listing was in the field at the time discussions about this initiative started, therefore no change was made to the Independent Listing sample.

As a result of the sample reduction, in addition to the pre-specified subsampling of small block clusters which occurred before Initial Housing Unit Computer Matching, the sample clusters were reduced from 12,364 to 6,416 block clusters. During Initial Housing Unit Computer Matching, the housing unit addresses in these 6,416 block clusters were computer matched against the housing units and group quarters addresses in the 2010 Census Universe Control and Management file within each remaining in-sample block cluster and one ring of surrounding blocks^/1. The results of computer matching were preprocessed with clerical matching software to assign initial match codes to the Census Coverage Measurement and census addresses. Addresses were assigned one of four initial/computer match codes: match, possible match, nonmatch, and duplicate.

During Initial Housing Unit Before Followup Clerical Matching, the National Processing Center matching staff used computer-assisted clerical matching techniques, along with Census Coverage Measurement and census maps, to attempt to match addresses presented to them after preprocessing^/2 of the Initial Housing Unit Computer Matching results. In addition, the matching staff searched for possible duplicate addresses in the census or Census Coverage Measurement files. A technician first coded each case flagged for review and then a sample of the cases was reworked for quality control by the matching analysts (a higher level of matching staff). Analysts also worked more difficult cases referred to them by the technicians. Cases that remained unresolved were eligible for Initial Housing Unit Followup. The Initial Housing Unit Followup operation attempted to collect additional information to resolve discrepancies between the survey and census listings, and between census or survey possible duplicates. In Initial Housing Unit After Followup Clerical Matching, the matching staff reviewed the followup data to make several important decisions, including: determining if records were duplicated; determining whether or not the address was a housing unit at the time of Initial Housing Unit Followup; identifying addresses that were incorrectly geocoded; verifying possible matches; and identifying additional matches. The results of this operation were files containing the final Initial Housing Unit match codes for Census Coverage Measurement and census housing units in the sample block clusters.

All Census Coverage Measurement field operations were managed from the 12 Regional Census Centers. Overall the field and matching operations for the 2010 Census Coverage Measurement Initial Housing Unit Independent Listing, Matching, and Followup operations were on schedule, although some special arrangements had to be made to complete the translation of materials for Puerto Rico operations and finish the followup field work in Puerto Rico. These special arrangements did not negatively affect any later operations.

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¹ Surrounding blocks include all blocks that are in the first ring of census collection blocks surrounding a block cluster. (Blocks in the first ring share one or more geographic points with the block cluster.) Any land block completely enclosed by blocks that are in the first ring, is also considered to be a surrounding block.

² The results of computer matching which had linked and non-linked addresses were preprocessed for clerical matching and assigned one of the four initial match codes – match, possible match, nonmatch, and duplicate.