United States Government Accountability Office

GAO Report to Congressional Committees

2010 CENSUS 

Census Bureau Needs 

to Take Prompt 

Actions to Resolve 

Long-standing and 

Emerging Address and 

Mapping Challenges 

June 2006 

 

GAO-06-272 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

June 2006

2010 CENSUS

Census Bureau Needs to Take Prompt 

Actions to Resolve Long-standing and 

Emerging Address and Mapping 

Challenges 

Highlights of GAO-06-272, a report to 

congressional committees 

To conduct a successful census, it

is important that the U.S. Census

Bureau (Bureau) produce the most 

complete and accurate address file

and maps for 2010. For this review, 

GAO’s specific objectives were to 

determine the extent to which (1) 

the Bureau’s efforts to modernize 

the address file and maps are 

addressing problems experienced 

during the 2000 Census, (2) the 

Bureau is managing emerging 

address file and map issues, (3) the

Bureau is able to collect and 

transmit address and mapping data 

using mobile computing devices 

(MCD) equipped with global 

positioning system (GPS)

technology, and (4) the Bureau has 

a plan to update the address file

and maps in areas affected by 

hurricanes Katrina and Rita. GAO

reviewed the Bureau’s progress in

modernizing both the address file

and maps. 

What GAO Recommends

GAO recommends that the

Secretary of Commerce direct the 

Bureau to mitigate risks in building

its address file and maps. Specific 

actions include setting firm dates 

to complete research and 

evaluations and develop resulting 

action plans; reevaluating the 

schedule and staffing workloads

for conducting address canvassing;

and developing plans to assess 

resources needed to update the 

address file and maps along the 

Gulf Coast. In commenting on a 

draft of this report, Commerce 

agreed with each of GAO’s three

recommendations. 

The Bureau’s address and map modernization efforts have progressed in 

some areas. The Bureau is researching how to correct addresses that were

duplicated, missed, deleted, and incorrectly located on maps. However,

some deadlines for completing research are not firm, while other deadlines 

that had been set continue to slip. Thus, whether research will be completed 

in enough time to allow the Bureau to develop new procedures to improve 

the 2010 address file is unknown. Also, the Bureau has not fully addressed 

emerging issues. For one such issue, the Bureau has acknowledged the 

compressed time frame for completing address canvassing—an operation 

where census workers walk every street in the country to verify addresses 

and maps—but has not reevaluated the associated schedule or staffing 

workloads. Also, the Bureau has allotted only 6 weeks to conduct address 

canvassing it completed in 18 weeks in 2000 and expanded the operation 

from urban areas in 2000 to the entire country in 2010. 

Mobile Computing Devices for Collecting and Transmitting Field Data 

Whether the Bureau can collect and transmit address and mapping data 

using the MCD is unknown. The MCD, tested during 2006 address 

canvassing, was slow and locked up frequently. Bureau officials said the

MCD’s performance is an issue, but a new MCD to be developed through a 

contract awarded in March 2006 will be reliable. However, the MCD will not 

be tested until the 2008 Dress Rehearsal, and if problems emerge, little time 

will remain to develop, test, and incorporate refinements. If after the Dress 

Rehearsal the MCD is found unreliable, the Bureau could face the remote but 

daunting possibility of reverting to the costly paper-based census of 2000. 

Bureau officials do not believe a specific plan is needed to update the 

addresses and maps for areas affected by the hurricanes. Securing a count is 

difficult under normal conditions, and existing procedures may insufficient 

to update addresses and maps after the hurricanes’ destruction—made 

even more difficult as streets, housing, and population will be in flux. 

www.gao.gov/cgi-bin/getrpt?GAO-06-272.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Brenda S. 

Farrell at (202) 512-6806 or farrellb@gao.gov. 
Contents 

Letter 1

Results In Brief 3 

Background 6

Uncertainties Surround Completion of Ongoing MAF/TIGER 

Modernization Research 10 

Emerging Issues Related to Overlapping and Compressed 

Schedules Pose a Risk to MAF/TIGER Modernization Efforts 18 

Reliability of MCD to Conduct Address Canvassing Activities is

Unknown 20

Bureau Does Not Have a Specific Plan for Updating MAF/TIGER in 

the Aftermath of Hurricanes Katrina and Rita 22 

Conclusions 24

Recommendations for Executive Action 25 

Agency Comments and Our Evaluation 26 

Appendix I Scope and Methodology 28 

Appendix II Comments from the Department of Commerce 30 

Appendix III GAO Contact and Staff Acknowledgments 38 

GAO Contact 38 

Acknowledgments 38

Table 

Table 1: Status of Bureau Efforts to Resolve MAF/TIGER Issues 11 

Figures 

Figure 1: Key Operations Required for a Complete and Accurate 

MAF/TIGER for the 2000 Census 7 

Figure 2: Group Homes Can Resemble Housing Units 16 

Figure 3: TIGER Map Overlay of an Aerial Photograph 17 

Figure 4: Devastation in the Lower Ninth Ward in New Orleans, 

Louisiana 22

Page i GAO-06-272 2010 Census
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Page ii GAO-06-272 2010 Census
United States Government Accountability Office

Washington, DC 20548 

June 15, 2006 

The Honorable Susan M. Collins 

Chairman 

The Honorable Joseph I. Lieberman 

Ranking Member 

Committee on Homeland Security and Governmental Affairs 

United States Senate 

The Honorable Tom Coburn 

Chairman 

The Honorable Thomas R. Carper 

Ranking Minority Member 

Subcommittee on Federal Financial Management, Government 

Information, and International Security 

Committee on Homeland Security and Governmental Affairs 

United States Senate 

The Honorable Tom Davis 

Chairman 

The Honorable Henry A. Waxman 

Ranking Minority Member 

Committee on Government Reform 

House of Representatives 

The Honorable Michael R. Turner 

Chairman 

The Honorable William Lacy Clay 

Ranking Minority Member 

Subcommittee on Federalism and the Census 

Committee on Government Reform 

House of Representatives 

The decennial census is an important, constitutionally mandated activity 

undertaken by the federal government that is complex and costly—

estimated at $11.3 billion for the 2010 Census. The data that the census 

produces are used to reapportion the seats of the U.S. House of 

Representatives; realign the boundaries of the legislative districts of each

state; allocate hundreds of billions of dollars in federal financial 

assistance; and provide a social, demographic, and economic profile of the 

nation’s people to guide policy decisions at each level of government. The 

Page 1 GAO-06-272 2010 Census
U.S. Department of Commerce’s Census Bureau (Bureau) is responsible 

for conducting the decennial census, and the success of the census 

depends in large part on the ability of the Bureau to locate and deliver 

questionnaires to every person residing in the United States. To 

successfully accomplish this monumental task, the Bureau must maintain 

accurate address and map information for every location where a person

could reside. During the 2000 Census, Bureau evaluations estimated that of

the 116 million housing units in the final census count, about 2.3 million 

housing units were incorrectly included in the census and about 

 2.7 million housing units were missed. 

One of the Bureau’s principal objectives for the 2010 Census is

modernizing the Master Address File (MAF)—the Bureau’s repository of 

approximately 130 million addresses to which the Bureau expects to 

deliver census forms for the 2010 Census. The Bureau also works to 

ensure the accuracy of the associated mapping system, the Topologically

Integrated Geographic Encoding and Referencing (TIGER®) database.1

The Bureau hopes to improve the completeness and accuracy of 

MAF/TIGER through a combination of activities, including partnering with 

state and local governments to verify the address lists and maps and 

updating maps to reflect correct geographic features. The Bureau will also 

use satellite-based global positioning system (GPS) technology to correctly 

locate housing units and door-to-door canvassing to verify the status of all 

housing units. The combined cost of these efforts is estimated to be about

$536 million (nominal dollars). 

An important component of the Bureau’s attempts to modernize its 

address listing and mapping activities will be the planned use of relatively

new technology. For the first time, census workers will use a GPSequipped mobile computing device (MCD) to collect data in the field, 

including address and map data. The Bureau anticipates that the MCDs 

will be used in three major census operations, and their successful 

implementation would allow the Bureau to reduce the amount of paper 

used, process data in real time, and improve the quality of the information 

collected. 

Because of the critical importance of complete and accurate address lists 

and maps, under the Comptroller General’s statutory authority, we 

reviewed the Bureau’s progress in modernizing both MAF and TIGER. As 

 1

 TIGER is a registered trademark of the U.S. Census Bureau. 

Page 2 GAO-06-272 2010 Census
agreed with your offices, we are providing this report to you which 

contains information that will be useful for your oversight responsibilities 

of the decennial census. Our specific objectives were to determine the 

extent to which (1) the Bureau’s efforts to modernize the address file and 

maps are addressing problems experienced during the 2000 Census, 

(2) the Bureau is managing emerging MAF/TIGER issues, (3) the Bureau is 

able to collect and transmit address and mapping data using a MCD that is 

equipped with GPS technology, and (4) the Bureau has a plan to update 

the address file and maps in areas affected by hurricanes Katrina and Rita.

To meet these objectives, we analyzed relevant evaluations from the 2000 

Census and other studies conducted by the Bureau, the Department of 

Commerce Office of Inspector General, and other organizations. We also 

reviewed various documents describing the Bureau’s MAF/TIGER 

modernization efforts and interviewed knowledgeable Bureau officials 

about MAF/TIGER, including the Bureau’s plans to update MAF/TIGER in 

the wake of hurricanes Katrina and Rita. Further, to obtain a firsthand 

look at how the Bureau’s address-building operations and MCDs 

performed in a real-world environment, we observed address canvassing 

activities at the 2006 Census Test sites located at the Cheyenne River 

American Indian Reservation and Tribal Trust Lands in South Dakota and 

the central portion of Travis County, Texas. Address canvassing is an 

operation where census workers walk every street in the country, 

verifying addresses and updating maps. We conducted our work from June 

2005 through April 2006 in accordance with generally accepted 

government auditing standards. Additional information on our scope and 

methodology appears in appendix I. 

While the Bureau’s MAF/TIGER modernization efforts have progressed in 

a number of areas, it is not clear if research designed to resolve addressrelated issues from the last census will be completed in sufficient time to 

improve 2010 address-building activities. During the 2000 Census, the 

Bureau encountered a number of problems with the MAF, including 

addresses that were duplicated, missed, deleted, and incorrectly located 

on the maps. To address those problems, the Bureau has been conducting 

research and testing some operational changes. For example, the Bureau

is researching ways to capture missed addresses for housing units that 

were hard to find—often associated with apartments in small, multi-unit 

structures. However, some deadlines for completing research are not firm, 

while other deadlines that have been set continue to slip. As a result, it is 

not known whether the research and evaluation efforts currently under 

way will be completed in sufficient time to allow the Bureau to develop

Results In Brief 

Page 3 GAO-06-272 2010 Census
new methodologies and procedures for improving the MAF by June 2007, 

the Bureau’s announced deadline for baselining all program requirements. 

In addition, one major research effort using software to identify duplicate 

addresses (an estimated 1.4 million duplicate addresses were removed 

during the 2000 Census) did not work any better at identifying true 

duplicates than what the Bureau already had in place and will not be used 

in 2010. As a result, duplicate addresses may still be a problem for the 2010 

MAF, and if not detected, can result in reduced accuracy and increased 

cost. 

As the Bureau has planned for the 2010 Census, issues surrounding the 

schedule of address activities have emerged and have not been fully 

addressed. One such issue revolves around the planning and development 

of the census amid tight and overlapping schedules for updating addresses 

and map files. For example, Bureau officials estimate that TIGER maps for 

600 to 700 counties of 3,232 counties in the United States will not be 

updated in time to be part of the local update of census addresses 

(LUCA)—the Bureau’s program to give local, state, and tribal government 

officials the opportunity to review the address lists and maps and suggest 

corrections. LUCA participation is important because local knowledge 

contributes to a more complete and accurate address file, and not having

the most current TIGER maps could affect the quality of a local 

government’s review. Also, the Bureau has compressed the time frame for 

completing address canvassing—an operation where census workers walk 

every street in the country to verify addresses and update maps. The 

Bureau has allotted 6 weeks for verifying the nation’s inventory of 

116 million housing units, although the Bureau took 18 weeks to complete 

this operation for the 2000 Census. The time to complete address 

canvassing is a concern because the workload for address canvassing has

significantly expanded from including only urban areas in 2000 to 

including the entire country for 2010. Bureau officials acknowledged the 

compressed time frame and that, in some areas of the country, bad 

weather could result in more time being needed to complete address 

canvassing. Bureau officials did not provide a justification for reducing the 

amount of time by 12 weeks, but did state that they would need to adjust 

staffing levels to meet workload demands. 

The Bureau’s ability to collect and transmit address and mapping data 

using the MCD is not known. The performance of these devices is crucial 

to the accurate, timely, and cost-effective completion of address listing, 

nonresponse follow-up, and coverage measurement activities. During 2006 

testing, the MCD used to collect address and map data was slow and 

locked up frequently. As a result, the Bureau was unable to complete 

Page 4 GAO-06-272 2010 Census
address canvassing, even with a 10-day extension. Also, some census 

workers were not always able to get GPS signals for collecting coordinates 

for housing units. Bureau officials have acknowledged that the MCD’s 

performance is an issue, but believe that a new version of the MCD, to be 

developed under the Field Data Collection Automation (FDCA) contract 

awarded on March 30, 2006, will be reliable and functional. However, 

because the 2008 Dress Rehearsal will be the first time this new MCD will 

be tested under census-like conditions, it is uncertain how effective that 

MCD will be, and if problems do emerge, little time will be left for the 

contractor to develop and test any refinements. Further, if after the dress 

rehearsal the MCD is found not to be reliable, the Bureau could be faced

with the remote, but daunting, possibility of having to revert to a costly 

paper-based census used in 2000. 

Finally, Bureau officials do not believe they need to have a specific plan to

update the address and maps files for those areas affected by hurricanes 

Katrina and Rita. Securing a complete count is difficult under normal 

circumstances, and the destruction caused by the hurricanes makes it 

even more difficult because the baseline information the Bureau must 

work with—streets, housing, and the population itself—will be in flux for 

some time to come. Bureau officials stated that by 2009, when address 

fieldwork is set to begin, residents will have decided whether to return to 

the affected region. Therefore, they believe that by 2009, they will be in a 

better position to add or delete addresses in the Gulf region affected by

the hurricanes. However, Bureau officials could not provide support for 

the 2009 date, nor have they identified local partners with whom they can

monitor this situation. Given the magnitude of the area affected and the 

degree of destruction, this approach may not be adequate. As a result, the

quality of the address and map files could be reduced if the Bureau is not 

prepared to conduct address operations in those areas affected by 

hurricanes Katrina and Rita. 

In conversations with Bureau officials, it became apparent to us that they 

are keenly aware of the existing time constraints and challenges detailed

in this report. However, the Bureau had not developed risk mitigation 

plans to address these challenges. Our recommendations, therefore, are 

intended to make transparent for Bureau and congressional decision 

makers how those challenges can and should be addressed. At a minimum, 

the Bureau should have a risk-based mitigation plan in place that includes 

specific dates for completing research on the address file and an approach

for exploring the difficulties the Bureau may face in updating MAF/TIGER 

along the Gulf Coast. Because time is running short, it is imperative that 

the Bureau continue to stay focused on identifying and resolving problems 

Page 5 GAO-06-272 2010 Census
to help ensure that the most accurate and complete address file and maps 

are produced for the 2010 Census. To facilitate this, we recommend that 

the Secretary of Commerce direct the Bureau to address methodological,

timing, and procedural improvements to building its address file and maps. 

Specific actions include (1) establishing firm deadlines to complete 

research, testing, and evaluations of the MAF to prevent missed, deleted, 

or duplicate addresses and map errors, and develop an action plan that 

will allow sufficient time to affect the 2010 MAF/TIGER design; 

(2) reevaluating the 2010 address canvassing schedule in areas affected by 

bad weather as well as staffing levels to ensure that the status of all 

housing units are accurately verified throughout the entire country; and 

(3) developing a plan, prior to the start of LUCA in August 2007, that will 

assess whether new procedures, additional resources, or local 

partnerships are needed to update MAF/TIGER along the Gulf Coast for 

areas affected by hurricanes Katrina and Rita. 

On June 2, 2006, the Department of Commerce forwarded written 

comments from the Bureau on a draft of this report. The Bureau agreed 

with each of our three recommendations and also noted actions it was 

taking to address the recommendations. The Bureau’s comments also 

included some technical corrections and suggestions where additional 

context was needed, and we revised the report to reflect these comments 

as appropriate. The comments are reprinted in their entirety in appendix 

II. 

A complete and accurate address list is the cornerstone of a successful 

census, because it both identifies all households that are to receive a 

census questionnaire and serves as the control mechanism for following 

up with households that fail to respond. If the address list is inaccurate, 

people can be missed, counted more than once, or included in the wrong 

location. MAF is intended to be a complete and current list of all addresses 

and locations where people live or could live. The TIGER database is a 

mapping system that identifies all visible geographic features, such as type

and location of streets, housing units, rivers, and railroads. To link these 

two separate databases, the Bureau assigns every housing unit in the MAF 

to a specific location in the TIGER, a process called “geocoding.” 

Background 

As shown in figure 1, for the 2000 Census the Bureau’s approach to 

building complete and accurate address lists and maps consisted of a 

number of labor- and data-intensive operations that sometimes overlapped 

and were conducted over several years. This effort included partnerships 

with the U.S. Postal Service and other federal agencies; state, local, and 

Page 6 GAO-06-272 2010 Census
tribal governments; local planning organizations; the private sector; and 

nongovernmental entities. The Bureau employed thousands of temporary 

census workers to walk every street in the country to locate and verify 

places where people could live. Determining this was no simple task as 

Figure 1: Key Operations Required for a Complete and Accurate MAF/TIGER for the 

2000 Census

Page 7 GAO-06-272 2010 Census
people can reside in cars, sheds, illegally converted basements and 

garages, and similar nontraditional and often hidden living arrangements. 

For the 2000 Census, the Bureau found that the MAF/TIGER databases 

were less than complete and accurate. Although the number of errors was 

small in proportion to the total number of housing units at the national

level, the errors could be problematic at lower levels of geography for 

certain purposes for which census data are used, such as allocating federal 

assistance to state and local governments. 

According to Bureau evaluations conducted after the 2000 Census, the 

final census count contained approximately 116 million housing units. 

However, the address file used to conduct the 2000 Census also contained 

a number of errors.2

 Bureau evaluations estimate that there were 

• 0.7 million duplicate addresses, 

• 1.6 million vacant housing units misclassified as occupied, 

• 1.4 million housing units not included, 

• 1.3 million housing units improperly deleted, and 

• 5.6 million housing units incorrectly located on census maps. 

In light of these and other problems, the Bureau made enhancing the 

MAF/TIGER one of three critical components to support the 2010 Census. 

The other two components are replacing the long form questionnaire with 

the American Community Survey3

 and conducting a short-form-only 

decennial census that is supported by early research and testing. 

For the 2010 Census, the Bureau is making extensive use of contractors to 

provide a number of mission-critical functions and technologies. One of 

the technologies to be provided by a contractor is the MCD. Under a 

contract awarded on March 30, 2006, a new MCD will be developed for the 

2008 Dress Rehearsal. To date, the Bureau has tested two models of the 

MCD—one during the 2004 Census Test and another during the 2006 

 2

 The address file used to conduct the decennial census is referred to as the decennial 

master address file or DMAF. In this report we refer to the address file as the master 

address file (MAF). 

3

 The American Community Survey (ACS) will contain the same questions as the long form, 

but will be mailed monthly to an annual sample of 3 million housing units. With the smaller 

sample, the ACS is designed to provide the same information at the same level of 

geographic detail as the long form by means of continuous measurement methodology in

which survey responses will be accumulated over time. 

Page 8 GAO-06-272 2010 Census
Census Test. In January 2005, we reported that the MCD used during the 

2004 Census Test to collect nonresponse follow-up data experienced 

problems transmitting, and the mapping feature was slow. Consistent with 

our recommendations, the Bureau took steps to improve the dependability 

of transmissions and correct the speed of the mapping feature.4

Due to the critical role of contractors to help carry out the 2010 Census, 

we conducted a review of major acquisitions for the 2010 Census.5

footnote number should not start a line) In that report issued in May 2006, 

we highlighted the tight time frames the FDCA contractor has for 

developing and implementing systems to support the upcoming 2008 Dress 

Rehearsal and recommended that the Bureau ensure that all systems are 

fully functional and ready to be assessed in time for the Dress Rehearsal. 

In addition, on March 1, 2006, we testified on the status of the FDCA 

project. 6

 In that testimony, we discussed the need for the Bureau to 

• validate and approve a baseline set of operational requirements for the 

FDCA contract, because if not, the FDCA project would be at risk of 

having changes to requirements, potentially affecting its ambitious 

development and implementation schedule; 

• implement an effective risk management process that identifies, 

prioritizes, and tracks project risks; and 

• select detailed performance measures for tracking the contractor’s work. 

In response to our work, the Bureau stated that they plan to complete 

these activities as soon as possible. 

 4

 GAO, 2010 Census: Basic Design Has Potential, but Remaining Challenges Need

Prompt Resolution, GAO-05-9 (Washington, D.C.: Jan. 12, 2005). 

5

 GAO, 2010 Census: Census Bureau Generally Follows Selected Leading Acquisition 

Planning Practices, but Continued Management Attention Is Needed to Help Ensure

Success, GAO-06-277 (Washington, D.C.: May 18, 2006). 

6

 GAO, Census Bureau: Important Activities for Improving Management of Key 2010 

Decennial Acquisitions Remain to be Done, GAO-06-444T (Washington, D.C.: Mar. 1,

2006). 

Page 9 GAO-06-272 2010 Census
While the Bureau’s MAF/TIGER modernization efforts have progressed in 

a number of areas, uncertainties and risks remain in dealing with addressrelated problems that affected the 2000 Census. Currently it is not known 

whether ongoing research to resolve those problems will be completed in 

sufficient time to allow the Bureau to develop new methodologies and 

procedures for improving the MAF by June 2007—the Bureau’s announced 

deadline for baselining all program requirements. One significant cause for 

this uncertainty is that some deadlines for completing research do not 

have firm dates, while other deadlines that have been set continue to slip. 

In addition, one major research effort using software to identify duplicate 

addresses (an estimated 1.4 million duplicate addresses were removed 

during the 2000 Census) did not work any better at identifying true 

duplicates than what the Bureau already had in place and will not be used 

in 2010. As a result, duplicate addresses may still be a problem for the 2010 

MAF, and to the extent they are not detected, can result in reduced 

accuracy and increased cost. 

During the 2000 Census, the Bureau encountered a number of problems 

with the MAF including (1) missed addresses, where the Bureau failed to 

include addresses in the MAF; (2) improperly deleted addresses, where the 

Bureau removed otherwise valid addresses from the MAF; (3) duplicate

addresses, with two or more addresses for the same housing unit; and 

(4) geocoding errors, where addresses were improperly located on a 

census map.7

 All of the errors affect the quality of census data. When 

detected, the errors can increase the cost of the census to the extent they

result in rework. Moreover, these errors are associated with a variety of 

living arrangements and addresses, including small, multi-unit dwellings; 

dormitories, prisons, and other group living facilities, known collectively 

as “group quarters,” as well as hidden housing units, such as converted 

basement apartments. As shown in table 1, to address those problems the 

Bureau has been conducting research and making some operational 

changes. 

Uncertainties 

Surround Completion 

of Ongoing 

MAF/TIGER 

Modernization 

Research 

 7

 Another type of MAF error identified by the Bureau is misclassifying a housing unit as

occupied when it is vacant. However, our focus is on whether an address has been properly

captured in the MAF and not the occupancy status of the address. Therefore, we do not

discuss occupancy errors in this report. 

Page 10 GAO-06-272 2010 Census
Table 1: Status of Bureau Efforts to Resolve MAF/TIGER Issues 

Types of errors

identified in 2000 

Primary reasons for those 

errors 

Type of dwelling most

likely affected Actions taken by Bureau Status of current effort 

Missed addresses Some housing units are 

difficult to identify. 

Small multi-unit 

structures. 

Testing new method to 

identify clusters of small 

multi-units. 

Testing to be completed 

by end of 2006. 

Improperly deleted 

addresses 

Varied. Varied. Tested new method for 

verifying the status of all 

housing units marked as 

deleted in 2006 address 

canvassing testing. 

Evaluation was due 

January 2006 and that 

date has been moved to 

April 2006. The evaluation 

was not available at the 

time of this review. 

Duplicate addresses Redundancy and overlap in

the address list building 

process. 

Address lists were created

separately for group 

quarters and housing units, 

and some addresses were

listed on both lists. 

Housing unit with a citystyle address. (e.g., 123 

Main Street) 

Group quarters. 

Tested address-matching 

software in 2004. 

Tested procedures during 

2004 and 2006 Census 

Tests to integrate group 

quarters and housing unit 

address lists. 

Results indicate matching 

software is not ready for 

2010 Census. 

2004 evaluation indicated 

progress is being made

for integrating address 

lists. Evaluation of 2006 

testing was due May 2006 

but was not available at 

the time of this review. 

Geocoding errors Maps not accurate. Varied. Collected GPS

coordinates for housing 

units in the 2004 and 

2006 tests. 

Hired contractor to update 

maps. 

2004 test results indicate 

that workers only used

GPS 55 percent of the 

time. 

Evaluation was due 

January 2006 and that 

date has been moved to 

April 2006. The evaluation 

was not available at the 

time of this review. 

Contractor updating maps 

and will be finished in April 

2008. 

Source: GAO analysis of Census Bureau data. 

Research to Identify 

Hidden Housing Units Is 

Progressing, but 

Completion Date Is 

Uncertain 

Although research to find hidden housing units holds promise for a more 

accurate census, whether the results will be delivered in time to be useful 

for the 2010 Census is uncertain. While Bureau officials do not have a firm 

date for completing this research, they do estimate it will be completed by 

the end of 2006. 

Page 11 GAO-06-272 2010 Census
According to Bureau evaluations, approximately 1.4 million housing units 

were missed in the 2000 Census. Missed addresses often result when 

temporary census workers do not recognize that particular structures, 

such as tool sheds, are being used as residences. Addresses can also be 

missed when census workers fail to detect hidden housing units, such as 

basement apartments, within what appear to be single housing units. This 

is especially true for urban areas, where row houses have been converted

into several different apartments. If an address is not in the MAF, its 

residents are less likely to be included in the census. 

In May 2003, Bureau staff met with the New York City Planning

Department to discuss and observe the address problems associated with

small multi-unit structures in Queens, New York. After the visit, the 

Bureau concluded that delivering questionnaires to small multi-unit 

structures was a problem that needed to be addressed. In response, the 

Bureau is using the MAF to identify urban areas, including Baltimore, an 

area west of Chicago, and counties in New Jersey, where small multi-unit 

dwellings exist, fitting the description of those that were missed.8

According to Bureau officials, to accurately identify and count these 

missed housing units, the Bureau would use update/enumerate 

procedures—where census workers update the address list and conduct 

interviews to collect census data—instead of using mailout/mailback 

procedures, where census forms are mailed to the housing units. 

Update/enumerate procedures are more labor–intensive and costly than

mailout/mailback procedures. 

In reviewing the research plan on small multi-unit structures,we found no 

milestones for completing this research. Bureau officials could not provide 

a firm completion date, but estimated that the research would be 

completed by the end of 2006. Without clear milestones for completing this 

research and action plans based on research results, it is uncertain 

whether the Bureau will have sufficient time to develop a methodology for 

identifying all the problematic locations across the country where 

update/enumerate methodology would be necessary and to inform 

decision makers on the cost of converting these areas from 

mailout/mailback procedures to update/enumerate procedures. 

 8

 The research project regarding small multiunit structures is also about avoiding duplicate 

enumerations caused by confusion during mail delivery, as well as follow-up operations. 

Page 12 GAO-06-272 2010 Census
The Bureau has tested new procedures to validate whether an address 

initially marked “delete” should be removed from the address file. 

However, the results from that testing, due January 2006, were delayed 

until April 2006, and were not available at the time of this review. 

For the 2000 Census, the Bureau found that it had mistakenly deleted 

1.3 million existing housing units from the address file used to conduct the 

census. In some instances, this occurred when the Bureau deleted an 

address that the U.S. Postal Service had coded as a business address, 

although people were living at that address. According to a Bureau 

evaluation, when this happens, the Bureau relies on census workers to 

find and add back those units. Bureau officials stated that identifying 

residential housing units is difficult for some structures, such as 

apartments in businesses. 

Research to Prevent Valid 

Addresses from Being 

Deleted Is Ongoing, but 

Completion Date Has 

Slipped 

The Bureau would also delete an address if no census form was returned 

from the unit and if two other census operations determined that the 

address should be deleted. A Bureau evaluation found that this process 

identified and removed 8.3 million nonexistent addresses; however, about 

653,0009

 of those addresses were valid and should not have been deleted. 

The evaluation does not provide an explanation for why these valid 

addresses were deleted or what could be done in the future to prevent 

valid addresses from being removed. Concerned that valid addresses were 

deleted, the Bureau, for the 2006 Census Test of address canvassing, tested

a new follow-up quality check procedure designed to verify the status of 

all addresses that were identified as “delete” during the address canvassing 

operation. The 2000 Census did have a follow-up operation, but not one 

specifically for all deleted addresses during the canvassing operation. By

building this quality control operation into the address canvassing 

operation, the Bureau hopes to prevent valid addresses from getting 

inadvertently deleted. An assessment report of address procedures that 

were tested in 2005 as part of the 2006 address canvassing operation was 

to be completed by January 2006. However, the deadline for this 

assessment slipped until the end of April 2006, and was not available at the 

time of this review. 

 9

 These approximately 653,000 valid addresses that were deleted are a subset of the 1.3

million addresses mistakenly deleted. 

Page 13 GAO-06-272 2010 Census
The Bureau has taken actions to prevent duplicate addresses. However, 

one research effort to identify duplicates using software was found to be 

ineffective because approximately 10 percent of the time the software 

would incorrectly identify a valid address as a duplicate address, and as a 

result, this software will not be used in 2010. According to Commerce 

officials, it is their philosophy to favor the inclusion of addresses in the 

census process over the exclusion of addresses. Nevertheless, preventing

duplicate addresses in the MAF saves the Bureau from having to make 

unnecessary and expensive follow-up visits to households already 

surveyed. Furthermore, preventing duplicate responses also enhances the 

accuracy of the data. 

Research Efforts on 

Duplicate Addresses Have 

Mixed Results 

Bureau studies initially estimated that during the 2000 Census, about 

2.4 million duplicate addresses existed in the MAF. The problem was so 

significant that in the summer of 2000, the Bureau initiated a special 

follow-up operation10 to identify and remove duplicate addresses. Research 

from this special operation confirmed that 1.4 million addresses were 

duplicates, and the Bureau removed those addresses from the census. 

However, the operation was not able to determine with certainty whether 

the remaining 1 million addresses were duplicates. As a result, according 

to Commerce officials, the 1 million addresses were not removed from the 

census because those addresses were believed to be a combination of 

apartment mix-ups and misdelivery of questionnaires, and not duplicates. 

Had the Bureau identified these 1.4 million housing units before 

nonresponse follow-up had occurred, it could have saved 

$39.7 million (based on our estimate that a 1 percentage point increase in 

workload could add at least $34 million in direct salary, benefits, and 

travel costs to the price tag of nonresponse follow-up).11 Even after the 

special operation to remove duplicates was completed, the Bureau still 

estimated that approximately 0.7 million duplicates remained in the MAF 

in error. 

According to Bureau officials, duplicate addresses resulted from the 

multiple operations used to build the MAF. While the redundancy of 

having multiple address-building operations helps produce a more 

 10 An unduplication operation in the summer of 2000 was implemented to identify and 

remove duplicate addresses. This operation was not a part of the original 2000 Census plan, 

but was considered necessary. 

11 GAO, 2000 Census: Contingency Planning Needed to Address Risks That Pose a Threat 

to a Successful Census, GAO/GGD-00-6 (Washington, D.C.: Dec. 14, 1999). 

Page 14 GAO-06-272 2010 Census
complete and accurate address list because more opportunities exist for 

an address to be added to the MAF, any variations in city-style addresses, 

which are addresses with house numbers and street names, could produce 

a duplicate entry. For example, the Postal Service, which is the source of

many addresses in the MAF, might refer to an address in its database as 

123 Waterway Point. A census worker in another address operation might 

record that address as 123 South Waterway Point. If not detected, two 

addresses would remain in the MAF for this single residence. To help 

resolve this problem, in 2004, the Bureau tested whether it could detect

duplicate addresses in the MAF by using computerized matching software 

to link variations in street addresses. In test results, the Bureau found that

90 percent of the potential duplicates identified by the process of 

“probablistic matching” were actual duplicates, while 10 percent were 

valid addresses. Because the number of false duplicates was significantly 

high, the Bureau decided against incorporating this approach into its plans 

for 2010 and planned no further testing of the software. As a result of not 

being able to use this software, duplicate addresses may still be a problem 

for the 2010 MAF, and duplicate addresses that are not detected can 

reduce accuracy and increase costs. 

At the same time, the Bureau has made some progress toward preventing

duplicates. The Bureau is testing new methods to resolve difficulties in 

distinguishing group quarters (which include dormitories, prisons, group 

homes, and nursing homes) from housing units, such as single-family 

homes and apartments. In the 2000 Census, the Bureau used different 

operations and compiled separate address lists for group quarters and 

housing units. Group quarters are sometimes difficult for census workers 

to identify because they often look the same as conventional housing units

(see fig. 2). As a result, these homes were sometimes counted twice during 

the 2000 Census—once as a group quarter and once as a housing unit. 

Page 15 GAO-06-272 2010 Census
Figure 2: Group Homes Can Resemble Housing Units 

One approach to help prevent duplicates that the Bureau tested during the 

2004 and 2006 Census Tests is integrating the two address lists and then 

verifying potential group quarters on that list. Evaluation results from the 

2004 testing showed progress was being made for integrating the address 

lists. The operational assessment report on the 2006 group quarters testing 

validation/advance visit operation that occurred in 2005, as a part of the 

address canvassing operation for the 2006 Census Test, was expected by

May 30, 2006, and was not available at the time of this review. 

Mixed Progress Is Being 

Made to Properly Identify 

and Locate Housing Units 

on TIGER Maps 

The Bureau is using a contractor to update its TIGER maps and intends to

use GPS technology to locate every housing unit across the country 

precisely. Collectively, these two efforts are designed to avoid the 

geocoding errors of the 2000 Census, when residences were sometimes 

counted in the wrong census block. However, progress can be hindered if

technical problems associated with the GPS continue. 

Bureau evaluations estimated that in 2000, of the nation’s approximately 

116 million housing units, 5.6 million (about 4.8 percent) housing units in 

the country were counted in the wrong locations. Resolving geocoding 

Page 16 GAO-06-272 2010 Census
errors will be important, as census data are used to redraw congressional 

lines and allocate federal assistance and state funding. For example, in 

June 2005, we reported that Soledad, California, lost more then $140,000 in 

state revenue when a geocoding error caused over 11,000 Soledad 

residents to be miscounted in two nearby cities.12

Geocoding errors are partly attributable to inaccuracies in the TIGER 

maps that census workers use to verify the locations of residences. As 

shown in figure 3, roads and other features on TIGER maps did not always 

reflect their true geographic locations. 

Figure 3: TIGER Map Overlay of an Aerial Photograph

To help improve TIGER maps, in June 2002, the Bureau awarded an 8-year, 

$200 million contract to correct in TIGER the location of every street, 

boundary, and other map feature so that they are aligned with their true 

geographic locations, among other contractual tasks. This work is to be 

 12 GAO, Data Quality: Improvements to Count Correction Efforts Could Produce More 

Accurate Census Data, GAO-05-463 (Washington, D.C.: June 20, 2005). 

Page 17 GAO-06-272 2010 Census
completed on a county-by-county schedule. According to Bureau officials, 

as of March 2006, nearly 1,700 county maps have been completed, with 

about another 1,600 to be completed by April 2008. 

In conjunction with updating TIGER, the Bureau, as part of its 2010 

address canvassing operations, plans to have census workers capture the 

exact location of every structure on the address list by using GPS 

receivers. This approach has the potential to resolve the cause of many 

geocoding errors; however, as we discuss later in this report, when this 

operation was tested as part of the 2006 Census Test, the GPS receiver did 

not always operate properly, leaving some housing units without a GPS 

coordinate to determine their locations. As part of the address canvassing

operational assessment report, the Bureau will provide the number and 

type of map spots collected (GPS, manual, or attached multi-unit). This 

report, initially due in January 2006, has been delayed and was not 

available at the time of our review. 

Testing GPS coordinates was a part of the 2004 Census Test, and 

evaluations showed that workers only used the GPS receiver to capture 

the location of housing units 55 percent of time. The evaluation, however, 

did not address why census workers did not use the GPS receiver. 

As the Bureau has planned for the 2010 Census, issues surrounding the 

schedule of address activities have emerged and have not been fully 

addressed. One key challenge in conducting the 2010 Census is the 

Bureau’s ability to keep the myriad of census activities on track amid tight 

and overlapping schedules for updating addresses and maps. For example, 

in planning the various 2010 address list activities, Bureau officials 

estimate that TIGER maps for 600 to 700 counties (out of 3,232 counties in

the United States) will not be updated in time to be part of the local update 

of census addresses (LUCA)—a program through which the Bureau gives 

local, state, and tribal government officials the opportunity to review and 

suggest corrections to the address lists and maps for their jurisdictions.13

LUCA is to begin in August 2007, when, according to the current schedule, 

Emerging Issues 

Related to 

Overlapping and 

Compressed 

Schedules Pose a Risk 

to MAF/TIGER 

Modernization Efforts

 13 LUCA is an example of how the Bureau partners with external entities, tapping into their 

knowledge of local populations and housing conditions in order to secure a more complete

count. In the Census Address List Improvement Act of 1994, Pub. L. No. 103-430, codified as

13 U.S.C. § 16, Congress required the Bureau to develop a local address review program to

give local and tribal governments greater input into the Bureau’s address list development

process.

Page 18 GAO-06-272 2010 Census
the Bureau will still have to update 368 counties in 2008 alone. Because all 

updates will not have been completed, some counties will not have the 

most current maps to review, but instead will be given the most recent 

maps the Bureau has available. According to Bureau officials, some maps 

have been updated for the American Community Survey, but others have 

not been updated since the 2000 Census. LUCA participation is important 

because local knowledge contributes to a more complete and accurate

address file. Not having the most current TIGER maps could affect the

quality of a local government’s review. The Bureau is aware of the 

overlapping schedules, but officials stated that they need to start LUCA in 

2007 in order to complete the operation in time for address canvassing—

an operation where census workers walk every street in the country to 

verify addresses and update maps. Further, Commerce officials stated that 

the primary focus of the LUCA program is to review and update the 

address list and not to review and update maps; therefore, not having the 

improved maps should not affect the ability of LUCA participants to add or 

make corrections to the census address list. We, however, believe that 

improved maps would help LUCA participants to provide more accurate 

address data. 

The census schedule will be a challenge for address canvassing in 2010.

The Bureau has allotted 6 weeks for census workers to verify the nation’s 

inventory of approximately 116 million housing units. This translates into a 

completion rate of over 2.75 million housing units every day. The challenge 

in maintaining this schedule can be seen in the fact that for the 2000 

Census, the Bureau took 18 weeks just to canvass “city-style” address 

areas, which are localities where the U.S. Postal Service uses housenumber and street-name addresses for most mail delivery. However, a 

Bureau official could not explain why the schedule had been shortened by 

12 weeks, compared to the 2000 Census. 

Although Bureau officials agreed that more time will be needed to conduct 

the address canvassing operation, especially in the northern sections of 

the country where bad weather can hinder those operations, they have not 

reevaluated the schedule. A Bureau official stated that the Bureau would 

need to assess staffing levels to ensure it will be able to meet workload 

demands. Meeting the demands of the shortened time frame for 

completing address canvassing is a concern because the workload for 

address canvassing has significantly expanded from including only urban

areas in 2000 to including the entire country for 2010. Furthermore, in the 

summer of 2005, when address canvassing was conducted for the 2006 

test, the Bureau was unable to finish in 6 weeks because of problems with 

the new MCD and GPS technology. In its comments to a draft of this 

Page 19 GAO-06-272 2010 Census
report, Commerce officials said it would work to expand the address 

canvassing schedule to ensure that it can be done without having a 

negative impact on other critical decennial activities. 

The Bureau’s ability to collect and transmit address and mapping data 

using the MCD is not known. The performance of these devices is crucial 

to the accurate, timely, and cost-effective completion of address listing, 

nonresponse follow-up, and coverage measurement activities. During 2006 

testing, the MCD used to collect address and map data was slow and 

locked up frequently. As a result, the Bureau was unable to complete 

address canvassing, even with a 10-day extension. Also, some census 

workers were not always able to get GPS signals for collecting coordinates 

for housing units. Bureau officials have acknowledged that the MCD’s 

performance is an issue but believe that a new version of the MCD, to be 

developed under the Field Data Collection Automation (FDCA) contract 

awarded on March 30, 2006, will be reliable and functional. However, 

because the 2008 Dress Rehearsal will be the first time this new MCD will 

be tested under census-like conditions, it is uncertain how effective that 

MCD will be, and if problems do emerge, little time will be left for the 

contractor to develop, test, and incorporate any refinements. Moreover, if 

after the Dress Rehearsal the MCD is found to be unreliable, the Bureau 

could be faced with the remote, but daunting possibility of having to revert 

to the costly paper-based census used in 2000. 

During the address canvassing operation, the technical problems with the 

MCDs were so significant that the operation did not finish as scheduled.

14

The 6 week operation was expected to run through September 2, 2005, but 

had to be extended by 10 days (through Sept. 12, 2005). However, the 

Bureau was still unable to finish the operation, leaving six assignment 

areas in Travis County, Texas and four assignment areas at the Cheyenne

River Reservation, South Dakota not canvassed. 

Reliability of MCD to 

Conduct Address 

Canvassing Activities 

is Unknown 

Bureau Is Unable to 

Complete Address 

Canvassing Operation 

Because of Technical 

Difficulties with the MCD 

To conduct address canvassing, each MCD was loaded with address 

information and maps and was also equipped with GPS. Census workers 

were trained to locate every structure in their assignment area, as well as 

 14As noted earlier in this report, during the 2004 Census Test the Bureau also experienced 

problems with the MCD (different model than the one used in the 2006 Census Test) used 

to collect nonresponse follow-up data. Specifically, that MCD had difficulties transmitting 

work and was slow to load maps. 

Page 20 GAO-06-272 2010 Census
to compare the locations of housing units to address and map data on the 

MCD and update the data accordingly. They also were instructed to 

capture each housing unit’s GPS coordinates. However, workers we 

observed and interviewed had problems updating address and map data as

well as collecting GPS coordinates, largely because the device’s software 

and GPS receiver were unstable. For example, we observed census 

workers unable to complete their planned assignments for the day 

because it took too long to complete address and map updates, as the 

device was slow to pull up and exit address registers, accept the data 

entered by the worker, and link a map spot to addresses for multi-unit 

structures. Furthermore, the devices would often lock up, requiring 

workers to reboot them. 

Census workers also experienced problems with the GPS receiver 

acquired by the Bureau. Some workers had problems getting a signal, but

even when a signal was available, the GPS receiver was slow to locate 

assignment areas and provide coordinates for map spots. Bureau officials 

were not certain why the Bureau’s equipment was unreliable, but provided 

several possible explanations: (1) the software, hardware, or both did not 

function properly, (2) GPS units were not correctly inserted into the 

device, and (3) too few satellites were available for capturing coordinates.

Given the importance of GPS to collecting precise coordinates for housing 

units, it will be important for the Bureau to understand and correct the 

source of the problems that affected the reliability of the GPS. 

Going into address canvassing, the Bureau was aware that the MCDs had 

software problems and delayed the address canvassing operation by a 

month to try to resolve them. The Bureau was unable to resolve the 

problems, but wanted to test the feasibility of the MCD and decided to go 

forward with the operation with the goal of learning as much as possible. 

For the 2008 Dress Rehearsal, the Bureau plans to test a new MCD that is 

being developed under the FDCA contract. However, less than a year 

remains for the contractor to develop the MCD that will be used in April 

2007 for the canvassing operation of the 2008 Dress Rehearsal. In a May

2006 report,15 we reported on the tight time frames to develop the MCD 

and recommended that systems being developed or provided by 

contractors for the 2010 Census—including the MCD—be fully functional

and ready to be assessed as part of the 2008 Dress Rehearsal. In

commenting on a draft of this report, Commerce noted that the Bureau 

 15 GAO-06-277. 

Page 21 GAO-06-272 2010 Census
designed the FDCA acquisitions strategy to reduce risks related to cost, 

schedule and performance, stating that the Bureau required offerors to 

develop and demonstrate a working prototype for address canvassing. 

Nevertheless, because the previous two MCD models had performance 

problems, the introduction of a new MCD adds another level of risk to the 

success of the 2010 Census. 

The Bureau does not have a plan to update the MAF/TIGER for areas 

affected by hurricanes Katrina and Rita. On August 29, 2005, Hurricane 

Katrina devastated the coastal communities of Louisiana, Mississippi, and 

Alabama. A few weeks later, Hurricane Rita plowed through the border 

areas of Texas and Louisiana. Damage was widespread. In the wake of 

Katrina, for example, the Red Cross estimated that nearly 525,000 people 

were displaced. Their homes were declared uninhabitable, and streets, 

bridges, and other landmarks were destroyed. Approximately 90,000 

square miles were affected overall and, as shown in figure 4, entire 

communities were obliterated. 

Bureau Does Not 

Have a Specific Plan 

for Updating 

MAF/TIGER in the 

Aftermath of 

Hurricanes Katrina 

and Rita 

Figure 4: Devastation in the Lower Ninth Ward in New Orleans, Louisiana 

The task of updating MAF/TIGER for 2010 to reflect these changes will be 

a formidable one, as much has changed since the 2000 Census. For the 

2010 Census, locating housing units and the people who reside in them will 

be critical to counting the population of places hit by the hurricanes, 

especially since it is estimated that hundreds of thousands of people 

Page 22 GAO-06-272 2010 Census
have—either temporarily or permanently—migrated to other areas of the 

country. To ensure an accurate count, it will be important for the Bureau 

to have accurate maps and an updated address file for the 2010 Census in

those areas affected by hurricanes Katrina and Rita. 

Bureau officials do not believe a specific plan is needed to update the 

address and map files for those areas affected by hurricanes Katrina and 

Rita. Although Census Day is still several years away, preliminary 

activities, such as operations for building the MAF, have to occur sooner.

Consequently, a key question is whether the Bureau’s existing operations 

are adequate for capturing the dramatic changes to roads and other 

geographic features caused by the hurricanes, or whether the Bureau 

needs to develop enhanced or additional procedures before August 2007 

when LUCA is scheduled to begin. For example, new housing and street 

construction in the areas affected by the hurricanes could require more 

frequent updates of the Bureau’s address file and maps. Also, local 

governments’ participation in LUCA might be affected because of the loss

of key personnel, information systems, or records needed to verify the 

Bureau’s address lists and maps. Further, the Bureau has not identified 

local partners with whom it can monitor this situation. 

The Bureau’s short-term strategy for dealing with the effect of the 

hurricanes on MAF/TIGER is to see who returns and whether communities 

decide to rebuild. Bureau officials stated that by 2009, as census workers 

prepare to go out in the field for address canvassing for the 2010 Census, 

residents will have decided whether to return to the region. The Bureau 

believes that by then it will be in a better position to add or delete 

addresses for areas in the Gulf region affected by the hurricanes. However, 

Bureau officials could not provide us with information on the basis of their 

conclusion that by 2009, most affected persons will have made final 

decisions about whether they are returning to the region. This approach 

may not be adequate, given the magnitude of the area, population, and 

infrastructure affected. Therefore, it would be prudent for the Bureau to 

begin assessing whether new procedures will be necessary, determining 

whether additional resources may be needed, and identifying whether 

local partners will be available to assist the Bureau in its effort to update 

address and map data, as well as in other census-taking activities. In its 

comments on a draft of this report, Commerce officials stated that there 

was a team working on how to reflect the impact of the hurricanes in the

MAF and that they were aware of the sensitive nature of working with 

local officials on using data that had not been updated since the 

catastrophe.

Page 23 GAO-06-272 2010 Census
Securing a complete count, a difficult task under normal circumstances, 

could face additional hurdles along the Gulf Coast, in large part because 

the baseline the Bureau will be working with—streets, housing, and the 

population itself—will be in flux for some time to come. According to 

Bureau officials, different parts of the agency work on hurricane-related 

issues at different times, but no formal body has been created to deal with

the hurricanes’ impact on the 2010 Census. 

The success of the 2010 Census relies on an accurate and complete MAF, 

and the Bureau has taken steps to improve the MAF. For example, many of 

the problems identified in the 2000 Census are being addressed through 

sequential address list building, the collection of GPS coordinates, and the 

verifications of deleted addresses. However, several key challenges and

sources of uncertainty remain. The management of some of the Bureau’s

research efforts to resolve problems from the 2000 Census are negatively 

affected by a lack of specific end dates for that research or because those 

end dates have slipped. Also, one research effort to prevent duplicate 

addresses was found to be ineffective and was abandoned altogether. 

Time to complete research and take the appropriate resulting action is of 

the essence, as the Bureau has announced that all design features should 

be baselined by June 2007. If long-standing problems are not resolved, the 

address file could experience the same problems with missed and 

incorrectly included housing units as it did in the 2000 Census. 

Conclusions 

The Bureau must also manage the planning and development of the census 

amid tight and overlapping schedules. In our view, changing milestones to 

complete MAF research, the Bureau’s tight development schedule for the

MCD, and the interdependence of the various address activities could 

affect the Bureau’s ability to develop a fully functional set of addressbuilding operations that can be tested along with other census operations 

during the 2008 Dress Rehearsal—the Bureau’s last opportunity to assess 

MAF/TIGER under near census-like conditions. If the MCDs do not 

function as planned in the Dress Rehearsal, little time will remain for the 

Bureau to develop, test, and incorporate any refinements. This uncertainty

places the accuracy and completeness of data collected using the MCD at 

risk. 

Because the MCD has not yet been developed, it will be important for the 

Bureau to closely monitor the contractor’s progress for developing the

MCD. In May 2006, we reported on the tight time frames to develop the 

MCD and recommended that systems being developed or provided by 

contractors for the 2010 Census—including the MCD—be fully functional

Page 24 GAO-06-272 2010 Census
and ready to be assessed as part of the 2008 Dress Rehearsal. However, if 

after the Dress Rehearsal the MCD is found to be unreliable, the Bureau 

could be faced with the remote but daunting possibility of having to revert 

to the costly paper-based census used in 2000. 

Finally, the destruction and chaos caused by hurricanes Katrina and Rita

underscore the nation’s vulnerability to all types of hazards and highlight 

how important it is for government agencies to consider emergency 

preparedness and continuity of operations as part of their planning. 

However, the immediate concern for the 2010 Census is that the Bureau 

has no plan for how it will successfully update MAF/TIGER in the affected 

hurricane zone. If problems updating the address file and maps do occur, 

the census count in those areas affected by hurricanes Katrina and Rita 

could be inaccurate or incomplete. 

In conversations with Bureau officials, it became apparent to us that they 

are keenly aware of the existing time constraints and challenges detailed

above. However, the Bureau had not developed risk mitigation plans to 

address these challenges. Our recommendations, therefore, are intended 

to make transparent for Bureau managers and congressional decision 

makers how those challenges can and should be addressed. At a minimum, 

the Bureau should have a risk-based mitigation plan in place that includes 

specific dates for completing research on the address file and an approach

for exploring the difficulties that the Bureau may face updating 

MAF/TIGER along the Gulf Coast. Because time is running short, it is 

imperative that the Bureau continue to stay focused on identifying and

resolving problems to ensure that the most accurate and complete address 

file and maps are produced for the 2010 Census. 

To mitigate potential risks facing the Bureau as it plans for 2010 and to

ensure a more complete and accurate address file for the 2010 Census, we 

recommend that the Secretary of Commerce direct the U.S. Census Bureau 

to take the following three actions: 

Recommendations for 

Executive Action 

• Establish firm deadlines to complete research, testing, and evaluations of 

the MAF to prevent missed, deleted, and duplicate addresses, as well as 

map errors, and develop an action plan that will allow sufficient time for 

the Bureau to revise or establish methodologies and procedures for 

building the 2010 MAF. 

• Reevaluate the 2010 address canvassing schedule in areas affected by bad 

weather, as well as staffing levels, to ensure that the status of all housing 

units are accurately verified throughout the entire country. 

Page 25 GAO-06-272 2010 Census
• Develop a plan, prior to the start of LUCA in August 2007, that will assess 

whether new procedures, additional resources, or local partnerships may 

be required to update the MAF/TIGER databases for areas along the Gulf 

Coast affected by hurricanes Katrina and Rita. 

On June 2, 2006, the Department of Commerce forwarded written 

comments from the Bureau on a draft of this report. The Bureau agreed 

with each of our three recommendations and also noted actions it was 

taking to address the recommendations. The Bureau’s comments also 

included some technical corrections and suggestions where additional 

context was needed, and we revised the report to reflect these comments 

as appropriate. The comments are reprinted in their entirety in appendix 

II. 

In responding to the first recommendation to develop an action plan that 

will allow sufficient time to revise or establish methodologies or 

procedures for building the 2010 MAF, the Bureau stated that it would 

revise its action plan to reflect final milestones for research to be 

completed in time for the 2010 Census. Regarding the second

recommendation to reevaluate the 2010 address canvassing schedule, as 

well as its staffing, the Bureau stated that this will be a challenge but that 

it is committed towards developing a new schedule. Finally, in addressing 

our third recommendation to develop a plan to assess whether new 

procedures, additional resources or local partnerships may be required to

update the MAF/TIGER databases for areas affected by hurricanes Katrina 

and Rita, the Bureau stated that it was working on a proposal for 

additional work in the areas affected by hurricanes Katrina and Rita. The 

Bureau also noted that conducting additional work will be subject to 

obtaining funding. 

We are sending copies of this report to other interested congressional 

committees, the Secretary of Commerce, and the Director of the U.S. 

Census Bureau. Copies will be made available to others upon request. This

report will also be available at no charge on GAO’s Web site at 

http://www.gao.gov. 

Agency Comments 

and Our Evaluation 

Page 26 GAO-06-272 2010 Census
Please contact me at (202) 512-6806 or farrellb@gao.gov if you have any 

questions about this report. Contact points for our Office of Congressional 

Relations and Public Affairs may be found on the last page of this report. 

Key contributors to this report are listed in appendix III. 

Brenda S. Farrell, Acting Director 

Strategic Issues 

Page 27 GAO-06-272 2010 Census
Appendix I: Scope and Methodology Appendix I: Scope and Methodology 

To determine the extent to which the Bureau’s MAF/TIGER modernization 

efforts are addressing problems experienced during the 2000 Census, we 

reviewed pertinent documents, including evaluations of the 2000 Census 

conducted by GAO, the Bureau, the National Academy of Sciences, and 

the Department of Commerce’s Office of Inspector General. To determine 

the status of those efforts, we also interviewed cognizant Bureau officials 

in the Geography Division and Decennial Management Division 

responsible for implementing the modernization efforts. To assess the 

extent to which past problems were being addressed, we compared the 

Bureau’s current efforts—including, but not limited to, the 2010 LUCA 

draft plan, 2004 and 2006 test plans, other research efforts, and TIGER 

improvement documents—to problems identified in evaluations of the 

2000 Census conducted by GAO, the Bureau, the National Academy of 

Sciences, and the Department of Commerce’s Office of Inspector General.

We reviewed the MAF/TIGER contract that was awarded in June 2002 to 

update the street and geographic features for the TIGER maps, as well as 

monthly earned-value management system (EVMS) cost and performance 

reports, to determine whether the deliverable schedule for the contract 

was on time and on budget. We did not independently verify the accuracy 

of the data contained in the EVMS cost and performance reports, but we 

did obtain a certification from the contractor that its EVMS was adequate 

to provide timely and accurate data from the Defense Logistics Agency. 

To determine the extent to which the Bureau is managing emerging 

MAF/TIGER issues, we focused on planning documents that described 

proposed 2010 plans. Specific documents we reviewed included the 2010 

LUCA draft proposal, 2010 Census decision memorandums, and Bureau 

papers from National Academy of Sciences and Census Advisory 

Committee meetings. We also reviewed and compared the timeline for 

conducting 2000 Census address operations to the proposed plan for 

conducting 2010 Census address operations. We interviewed officials from 

the Bureau’s Geography Division and the Decennial Management Division 

on the 2010 plans, 2010 time lines, current status of work, and areas of 

concern. 

To assess the extent to which the Bureau is able to collect and transmit 

address data using new, GPS-enabled mobile computing devices, we made 

site visits to census offices on the Cheyenne River Reservation, South 

Dakota, and in Travis County, Texas, where we observed the address 

canvassing operation conducted during the summer of 2005 as part of the 

2006 Census Test. During these site visits, we also interviewed local and 

regional census managers and staff, observed address data collection 

Page 28 GAO-06-272 2010 Census
Appendix I: Scope and Methodology 

activities using the MCD, and attended census worker training sessions. 

We observed and interviewed a total of 38 census workers (16 in South 

Dakota and 22 in Texas) about the address canvassing operation and the 

use of the MCD to collect address data. However, the results of these 

observations are not necessarily representative of the larger universe of 

census workers. After our visits, we discussed our observations with the 

Bureau’s Technology Management Office, Field Division, Geography 

Division, and Decennial Management Division. 

Finally, to determine the extent to which the Bureau has a plan to update

the address file and maps in areas impacted by hurricanes Katrina and 

Rita, we interviewed Bureau top management officials. Specifically, we 

discussed whether the Bureau had taken any steps to assess the 

difficulties it may encounter as it attempts to update the address file and 

maps and count persons affected by hurricanes Katrina and Rita. We 

conducted our work from June 2005 through April 2006 in accordance 

with generally accepted government auditing standards. 

Page 29 GAO-06-272 2010 Census
Appendix II: Comments from the Department Appendix II: Comments from the Department of Commerce 

of Commerce 

Page 30 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 31 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 32 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 33 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 34 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 35 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 36 GAO-06-272 2010 Census
Appendix II: Comments from the Department 

of Commerce 

Page 37 GAO-06-272 2010 Census
Appendix III: GAO

St

 Contact and 

aff Acknowledgments

Page 38 GAO-06-272 

Appendix III: GAO Contact and Staff 

Acknowledgments 

GAO Contact Brenda S. Farrell, (202) 512-6806 or farrellb@gao.gov

In addition to the contact named above, Carlos Hazera, Assistant Director; 

Sheranda Smith Campbell; Betty Clark; Tim DiNapoli; Robert Goldenkoff; 

Shirley Hwang; Sonya Phillips; Lisa Pearson; Ilona Pesti; and Brendan St. 

Amant made key contributions to this report. 

2010 Census

Acknowledgments 

(450420) 
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