What Users of Data for American Indians and Alaska Natives Need to Know i

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Issued

October 2009

U.S. Department of Commerce

Economics and Statistics Administration

U.S. CENSUS BUREAU

USCENSUSBUREAU

Helping You Make Informed Decisions

A Compass for Understanding and Using 

American Community Survey Data

What Users of Data for American Indians and 

Alaska Natives Need to Know
Acknowledgments Nancy K. Torrieri, Special Assistant to the Chief of the American Community 

Survey Offi ce, drafted this handbook for the U.S. Census Bureau’s American 

Community Survey Offi ce. Deborah H. Griffi n, Douglas Hillmer, Alfredo 

Navarro, Matthew A. Zimolzak, Wahler S. Sein, Cheryl V. Chambers, 

Cynthia Davis Hollingsworth, Pamela M. Klein, Anna M. Owens, Enid 

Santana Ortiz, Susan L. Hostetter, Colleen D. Flannery, Phillip M. 

Vidal, Michelle H. Lowe, Karen R. Humes, Nicholas A. Jones, 

Stella U. Ogunwole, Victoria A. Velkoff, Mark E. Asiala, Karen E. King, 

Michael R. Ratcliff e, Vincent Osier, Joshua J. Coutts, Janemary G. 

Rosenson, Colleen D. Joyce, Barbara Saville, Jeanne M. Woodward,

Arthur R. Cresce, Paul J. Mackun, Marc J. Perry, Dee A. Alexander,

Jan N. Jacobs, Gerald L. O’Donnell, and other staff from the Field Division 

Regional Offi ces of the Census Bureau; and Sarah Hicks and staff of the 

National Congress of American Indians Policy Research Center, as well as 

Norm DeWeaver, Consultant to the National Congress of American Indians, 

made suggestions or contributions regarding the initial content. Members of 

the Census Bureau’s American Indian and Alaska Native Advisory Committee, 

Deana K. O’Hara, Jacqueline Kruszek, and Emily Wright of the 

Department of Housing and Urban Development’s Offi ce of Native American 

Programs, and Cathy Carothers, Offi ce of Indian Education, U.S. Department 

of Education, also contributed to this review. 

Deborah H. Griffi n, Special Assistant to the Chief of the American Community 

Survey Offi ce, provided the concept and directed the development and 

release of a series of handbooks entitled A Compass for Understanding and 

Using American Community Survey Data. Cheryl V. Chambers, Colleen D. 

Flannery, Cynthia Davis Hollingsworth, Susan L. Hostetter, Pamela D. 

Klein, Anna M. Owens, Clive R. Richmond, Enid Santana, and Nancy K. 

Torrieri contributed to the planning and review of this handbook series.

The American Community Survey program is under the direction of Arnold A. 

Jackson, Associate Director for Decennial Census, Daniel H. Weinberg, 

Assistant Director for the American Community Survey and Decennial Census, 

and Susan Schechter, Chief, American Community Survey Offi ce.

Other individuals who contributed to the review and release of these 

handbooks include Dee Alexander, Herman Alvarado, Mark Asiala,

Frank Ambrose, Maryam Asi, Arthur Bakis, Genora Barber, Michael 

Beaghen, Judy Belton, Lisa Blumerman, Scott Boggess, Ellen Jean 

Bradley, Stephen Buckner, Whittona Burrell, Edward Castro, Gary 

Chappell, Michael Cook, Russ Davis, Carrie Dennis, Jason Devine,

Joanne Dickinson, Barbara Downs, Maurice Eleby, Sirius Fuller, Dale 

Garrett, Yvonne Gist, Marjorie Hanson, Greg Harper, William Hazard,

Steve Hefter, Douglas Hillmer, Frank Hobbs, Todd Hughes, Trina 

Jenkins, Nicholas Jones, Anika Juhn, Donald Keathley, Wayne Kei,

Karen King, Debra Klein, Vince Kountz, Ashley Landreth, Steve Laue,

Van Lawrence, Michelle Lowe, Maria Malagon, Hector Maldonado,

Ken Meyer, Louisa Miller, Stanley Moore, Alfredo Navarro, Timothy 

Olson, Dorothy Paugh, Marie Pees, Marc Perry, Greg Pewett, Roberto 

Ramirez, Dameka Reese, Katherine Reeves, Lil Paul Reyes, Patrick 

Rottas, Merarys Rios, J. Gregory Robinson, Anne Ross, Marilyn Sanders,

Nicole Scanniello, David Sheppard, Joanna Stancil, Michael Starsinic,

Lynette Swopes, Anthony Tersine, Carrie Werner, Edward Welniak,

Andre Williams, Steven Wilson, Kai Wu, and Matthew Zimolzak.

Linda Chen and Amanda Perry of the Administrative and Customer Services 

Division, Francis Grailand Hall, Chief, provided publications management, 

graphics design and composition, and editorial review for print and electronic 

media. Claudette E. Bennett, Assistant Division Chief, provided general 

direction and production management.
A Compass for Understanding and Using 

American Community Survey Data Issued October 2009

U.S. Department of Commerce

Gary Locke, 

Secretary

Dennis F. Hightower, 

Deputy Secretary

Economics and Statistics Administration

Rebecca M. Blank, 

Under Secretary for Economic Aff airs

U.S. CENSUS BUREAU

Robert M. Groves, 

Director

What Users of Data for American Indians and 

Alaska Natives Need to Know
Suggested Citation

 U.S. Census Bureau, 

A Compass for Understanding 

and Using American 

Community Survey Data:

What Users of Data for American 

Indians and Alaska Natives 

Need to Know

U.S. Government Printing Offi ce, 

Washington, DC, 

2009.

Economics and Statistics 

Administration

Rebecca M. Blank,

Under Secretary for Economic Aff airs

U.S. CENSUS BUREAU

Robert M. Groves,

Director

Thomas L. Mesenbourg,

Deputy Director and 

Chief Operating Offi cer

Arnold A. Jackson

Associate Director for Decennial Census

Daniel H. Weinberg

Assistant Director for ACS and Decennial Census 

Susan Schechter

Chief, American Community Survey Offi ce

ECONOMICS

AND STATISTICS

ADMINISTRATION
What Users of Data for American Indians and Alaska Natives Need to Know iii

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Contents Foreword...................................................................................................... iv

Introduction ..................................................................................................1

About the ACS ...............................................................................................2

ACS Data Products ........................................................................................6

ACS Data for Geographic Areas ....................................................................6

Understanding ACS Data: Before You Log On to American FactFinder .........8

Accessing ACS Data Products .......................................................................9

Data Product Examples ............................................................................... 10

Using ACS Data ........................................................................................... 21

Rules of the Road ....................................................................................... 22

Other Resources for Working With ACS Data .............................................. 25

The Census Bureau’s American Indian and Alaska Native Web Portal ........ 25

Conclusion .................................................................................................. 25

Glossary...................................................................................................... 27

Appendixes ................................................................................................A-1

 Appendix 1. The Geography of American Indian and Alaska Native Areas ..........A-1

 Appendix 2. Conducting a Test of Statistical Signifi cance ...................................A-4
iv What Users of Data for American Indians and Alaska Natives Need to Know 

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Foreword The American Community Survey (ACS) is a nationwide survey designed to 

provide communities with reliable and timely demographic, social, economic, and 

housing data every year. The U.S. Census Bureau will release data from the ACS in 

the form of both single-year and multiyear estimates. These estimates represent 

concepts that are fundamentally diff erent from those associated with sample 

data from the decennial census long form. In recognition of the need to provide 

guidance on these new concepts and the challenges they bring to users of ACS 

data, the Census Bureau has developed a set of educational handbooks as part of 

The ACS Compass Products. 

We recognize that users of ACS data have varied backgrounds, educations, 

and experiences. They need diff erent kinds of explanations and guidance to 

understand ACS data products. To address this diversity, the Census Bureau 

worked closely with a group of experts to develop a series of handbooks, each of 

which is designed to instruct and provide guidance to a particular audience. The 

audiences that we chose are not expected to cover every type of data user, but 

they cover major stakeholder groups familiar to the Census Bureau.

General data users Congress 

High school teachers Puerto Rico Community Survey data

 users (in Spanish)

Business community Public Use Microdata Sample (PUMS) data

 users

Researchers Users of data for rural areas

Federal agencies State and local governments

Media Users of data for American Indians and 

 Alaska Natives

The handbooks diff er intentionally from each other in language and style. Some 

information, including a set of technical appendixes, is common to all of them. 

However, there are notable diff erences from one handbook to the next in the 

style of the presentation, as well as in some of the topics that are included. We 

hope that these diff erences allow each handbook to speak more directly to its 

target audience. The Census Bureau developed additional ACS Compass Products

materials to complement these handbooks. These materials, like the handbooks, 

are posted on the Census Bureau’s ACS Web site: <www.census.gov/acs/www>.

These handbooks are not expected to cover all aspects of the ACS or to provide 

direction on every issue. They do represent a starting point for an educational 

process in which we hope you will participate. We encourage you to review these 

handbooks and to suggest ways that they can be improved. The Census Bureau 

is committed to updating these handbooks to address emerging user interests as 

well as concerns and questions that will arise. 

A compass can be an important tool for fi nding one’s way. We hope The ACS 

Compass Products give direction and guidance to you in using ACS data and that 

you, in turn, will serve as a scout or pathfi nder in leading others to share what 

you have learned. 
What Users of Data for American Indians and Alaska Natives Need to Know 1

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

A tribal planner needs current information about his 

reservation to plan for future economic development. 

Some of the information he needs is available from 

tribal administrative records. But other information that 

would contribute to a broad picture of the reservation’s 

characteristics must be obtained from other sources. 

Where can he turn?

A Commission for Indian Aff airs in a southeastern state 

wants to improve access to health services for tribal 

members. What information resources exist to support 

that need?

Tribal college administrators launch a 5-year plan to 

improve the curriculum and accessibility to courses. 

What kinds of data are available to identify the characteristics of potential students? 

A policy analyst at a federal agency wants to measure 

the eff ectiveness of programs that fund critical health 

care services to American Indian and Alaska Native 

populations nationwide. Where could she turn for assistance?

A national organization serving American Indians and 

Alaska Natives wants to advocate for programs that 

improve housing on reservations. What source of information could be important for the research needed to 

develop a legislative agenda?

Detailed information collected by the Census Bureau 

about the nation’s population and housing has served 

as an important resource to answer these questions. 

Until recently, this information was collected once 

every 10 years through a survey of about one-sixth 

of the U.S. population and housing. That survey was 

known as the decennial census long-form survey. It 

added complexity to census-taking and produced 

data that became increasingly outdated in the decade 

following each decennial census. To address these concerns, the Census Bureau proposed that the decennial 

census long-form survey be replaced by a continuous 

survey, called the American Community Survey (ACS), 

that produced more current information. After a period 

of testing and evaluation, the ACS was launched in 

2005, and the fi rst data products from the fullimplementation ACS were released in 2006. 

ACS data products, like the decennial census long-form 

data products of the past, are important to users of 

data for American Indian and Alaska Native populations (the abbreviation, “AIAN,” is occasionally used 

in this handbook to refer to these populations). This 

handbook, one of a series of handbooks targeted to 

specifi c audiences, is designed to explain how ACS 

data diff er from the Census 2000 long-form data and 

to provide information about how to access and use 

ACS data products. Key information is summarized in 

text boxes; charts and tables are used to supplement 

the text. A step-by-step guide to accessing examples 

of ACS data products is included. More detailed 

information about some topics is provided in a set of 

appendixes at the end of this handbook. A separate 

set of appendixes that appear at the end of 

A Compass for Understanding and Using American 

Community Survey Data: What General Data Users 

Need to Know, found at <http://www.census.gov/acs

/www/Downloads/ACSGeneralHandbook.pdf>, 

provides in-depth coverage of technical topics.

Introduction

What Is the American Community Survey and 

Why Are American Community Survey Data Important?

The American Community Survey (ACS) is a nationwide survey that produces detailed characteristics of 

population and housing. It is part of the 2010 Decennial Census Program. 

Like the decennial census long-form survey that preceded it, the ACS produces data on the characteristics 

of American Indians and Alaska Natives and the areas where they live. ACS data are important to tribal 

government offi cials, such as planners, and to federal and state government agencies and nongovernment 

organizations that provide services to improve the well-being of tribal populations.
2 What Users of Data for American Indians and Alaska Natives Need to Know 

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

The collection of detailed information about the 

nation’s population and housing has been part of the 

decennial census since 1790. The implementation of 

the ACS marks an important transition in collecting 

these data: the ACS design, methods, and data products have important diff erences from the decennial 

census long form that the ACS replaced. At the same 

time, the ACS embodies a data collection tradition that 

is familiar to data users. Like the decennial census 

long-form survey, the purpose of the ACS is to collect 

high-quality, current information. The content of the 

ACS questionnaire is similar to the content of decennial 

census long-form questionnaires of the past. Finally, 

many aspects of data collection for the ACS are similar 

to those used for other surveys. 

The ACS Questionnaire: Content

The ACS asks a broad range of questions on a variety of subjects. The questions are designed to collect 

information that is critical for managing federal programs. The decennial census long-form survey asked 

questions on the same kinds of subjects. The ACS 

includes questions on several new subjects that were 

not included on the decennial census long-form survey. 

Table 1 presents a list of the subjects that are included 

in the ACS.

About the ACS

 Table 1. Subjects Included in the American Community Survey

Demographic Characteristics

Age

Sex

Hispanic Origin

Race

Relationship to Householder 

(e.g., spouse)

Economic Characteristics

Income

Food Stamps Benefi t

Labor Force Status

Industry, Occupation, and Class 

of Worker

Place of Work and Journey to 

Work

Work Status Last Year

Vehicles Available

Health Insurance Coverage*

Social Characteristics 

Marital Status and Marital History*

Fertility

Grandparents as Caregivers

Ancestry

Place of Birth, Citizenship, and 

Year of Entry

Language Spoken at Home

Educational Attainment and 

School Enrollment

Residence One Year Ago

Veteran Status, Period of Military 

Service, and VA ServiceConnected Disability Rating*

Disability

Housing Characteristics

Year Structure Built

Units in Structure

Year Moved Into Unit

Rooms

Bedrooms

Kitchen Facilities

Plumbing Facilities

House Heating Fuel

Telephone Service Available

Farm Residence

Financial Characteristics

Tenure (Owner/Renter)

Housing Value

Rent

Selected Monthly Owner Costs

 *Marital History, VA Service-Connected Disability Rating, and Health Insurance Coverage were added in for 2008.

 Source: U.S. Census Bureau.

ACS Data for American Indian and Alaska Native 

Populations

Figure 1 shows the race question that appears on the 

ACS questionnaire (the 2009 ACS questionnaire may be 

found at <http://www.census.gov/acs/www/SBasics

/SQuest/SQuest1.htm>). A combined “American Indian 

or Alaska Native” category is designed to collect data 

on both American Indians and Alaska Natives. The 

responses to this question provide the information 

from which the estimates for American Indians and 

Alaska Natives are derived. The responses are based 

on self-identifi cation. Respondents are asked to report 

one or more races for themselves and other members 

of their households. Respondents who identify themselves as American Indian or Alaska Native are asked 

to report their enrolled or principal tribe. People can 

report more than one tribe. 

People who answer the question on race by marking 

only the “American Indian or Alaska Native” response 

box, and/or writing in one or more tribes, are referred 

to as the “American Indian and Alaska Native alone” 

population. People who answer the race question 
What Users of Data for American Indians and Alaska Natives Need to Know 3

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

race question, data on American Indians and Alaska 

Natives can be tabulated or shown on data tables in 

two broad minimum and maximum categories, namely, 

the American Indian and Alaska Native alone population and the American Indian and Alaska Native alone 

and in combination population. 

by marking the “American Indian or Alaska Native” 

response box and one or more other races, for example “American Indian or Alaska Native” and “White” or 

“American Indian or Alaska Native” and “Black,” are 

included in the “American Indian or Alaska Native in 

combination” population. Based on responses to the 

White

American Indian or Alaska Native — Print name of enrolled or principal tribe.

Black, African Am., or Negro

Asian Indian

Chinese

Filipino

Other Asian – Print race,

for example, Hmong, 

Laotian, Thai, Pakistani, 

Cambodian, and so on.

Native Hawaiian

Guamanian or Chamorro

Samoan

Other Pacific Islander – 

Print race, for example, 

Fijian, Tongan, and 

so on.

6 What is Person 1’s race? Mark (X) one or more boxes.

Japanese

Korean

Vietnamese

Some other race – Print race.

White

Ameri

Black, 

Asian 

Chines

Filipin

Other 

for exa Laotia Cambo

6 What is Pe

Some 

 Figure 1. The Race Question on the American Community Survey Questionnaire INFORMATIONA

Source: ACS questionnaire, accessed at <http://www.census.gov/acs/www/Downloads/SQuest09.pdf>.

What American Indian and Alaska Native Defi nition Is Used by 

the American Community Survey?

The racial classifi cations used by the Census Bureau adhere to the October 30, 1997, Federal Register

Notice entitled, “Revisions to the Standards for the Classifi cation of Federal Data on Race and Ethnicity” 

issued by the Offi ce of Management and Budget (OMB). These standards govern the categories federal 

agencies must use to collect and present federal data on race and ethnicity. The OMB standard requires 

fi ve minimum race categories (White, Black or African American, American Indian or Alaska Native, Asian, 

and Native Hawaiian or Other Pacifi c Islander). A sixth category, “Some other race,” was added to the ACS 

with OMB approval. In addition to the fi ve race groups, the OMB standard also states that respondents 

should be off ered the option of selecting one or more races. 

The OMB standard defi nes American Indian or Alaska Native as a person having origins in any of the 

original peoples of North and South America (including Central America) and who maintains tribal affi liation or community attachment. Tabulated data for this category include people who (1) indicate their 

race as “American Indian” or “Alaska Native”; (2) report the name of an American Indian tribe (for example, Navajo or Blackfeet) or Alaska Native tribe (for example, Inupiat or Yup’ik); or (3) report entries such 

as Canadian Indian, French American Indian, or Spanish American Indian.
4 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Census Bureau contacts households in person to conduct the ACS. Such areas are common in AIAN areas. 

The ACS is also conducted for group quarters, which 

include college dormitories, correctional facilities, 

and nursing facilities. Field representatives contact 

the selected facilities to arrange a visit to collect the 

required information from those residents. 

Like its predecessor, the decennial census long form, 

the ACS is a mandatory survey. Response is required by 

law. Data confi dentiality is protected by Title 13 of the 

U.S. Code (Title 13, U.S. Code, Sections 141, 193, and 

221). For more information on how the Census Bureau 

protects the confi dentiality of data for the ACS, see 

<http://www.census.gov/privacy/data_protection

/how_we_protect_your_information.html>.

ACS Data Collection, Data Processing, and 

Data Tabulation 

The ACS samples approximately 3 million housing unit 

addresses each year and collects information continuously, essentially every day of the year. Data are collected using three data collection methods or modes: 

mailout/mailback, Computer Assisted Telephone Interviewing, and Computer Assisted Personal Interviewing. ACS materials are mailed to city-style addresses, 

such as 123 Main Street, Anytown, XX 99987, and to 

non-city-style addresses such as Rural Route 1, Box 

54 A, Anytown, XX 99987. Follow-up activities for 

households that do not respond by mail take place by 

telephone or in person. For areas that do not have 

addresses to which questionnaires can be mailed, the 

Who Is Selected to Participate in the American Community Survey and 

How Often Are They Contacted? 

The ACS selects a sample of housing unit addresses and group quarters to participate in the 

ACS. In 2008, about 2.1 percent of all addresses in the United States were sampled. The size 

of the sampling rate varies based on the size of a governmental unit. Governmental units are 

legally defi ned entities that have elected offi cials and pay taxes. Examples of these entities are 

American Indian reservations, counties, and incorporated places.

For small areas, just a few addresses per month are selected for the survey; for other areas, 

many addresses per month are selected for the survey. In remote areas of Alaska, addresses 

are selected for the survey for some, but not all, months of the year because of the unique 

conditions and settlement patterns for those areas. The data collected for any area represent 

the characteristics of population in that area over the entire year. The ACS is designed to 

ensure that no address is selected more than once every 5 years.

The annual ACS sample is much smaller than that of 

the Census 2000 long-form sample, which included 

about one-sixth of the housing unit addresses in the 

United States, or about 18 million housing units. 

Because the overall sampling rate is smaller than that 

used for Census 2000 or previous censuses, the ACS 

needs to combine, or accumulate, population and 

housing data from multiple years to produce reliable 

estimates for small areas and population groups. The 

ACS sample is suffi cient to produce data for large communities or population groups of 65,000 or greater 

based on 1 year of data collection. However, to produce data for smaller communities, multiple years of 

data collection must be used. For areas of 20,000 or 

greater, 3 years of data collection are combined to produce reliable estimates. For areas of less than 20,000, 

5 years of data collection are needed. 

Following the collection of response data, data preparation and processing takes place to produce ACS estimates. During data preparation, the coding of write-in 

responses occurs. Data processing involves editing and 

imputation, as well as weighting and the application of 

disclosure avoidance techniques. Once edited fi les are 

fully reviewed, they are used to produce data products. 

ACS data products include tables, reports, fi les, and 

maps that are described later in this handbook. 

The decennial census long-form data products were 

released over the course of several years following 

a census. The ACS data release schedule appears in 

Table 2. Note that ACS data are released according to 

a schedule that it is distinctly diff erent from the data 

release schedule for decennial census long-form survey 

products. In 2006, the Census Bureau released 1-year 

estimates for 2005. In 2008, the fi rst 3-year estimates 

were released based on data collected in 2005, 2006, 

and 2007. In 2010, the fi rst 5-year ACS estimates will 

be released based on data collected in 2005, 2006, 

2007, 2008, and 2009. Note that each new 3- or 5-year 

estimate represents a period of data collection that is 

updated by one year from the previous 3- or 5-year 

estimate. The 3-year estimate released in 2009 represents data collection for the period 2006–2008. The 

3-year estimate released in 2010 represents data 

collection for the period 2007–2009. 
What Users of Data for American Indians and Alaska Natives Need to Know 5

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

The ACS and the Decennial Census Long-Form 

Survey Compared

The ACS and the decennial census long-form survey 

have many similarities, but there are distinct diff erences as well, as shown in Table 3.

As Table 2 shows, some areas will receive more than 

one kind of estimate. Note, for example, that for the 

2008 data release, areas having population thresholds 

of 65,000 or greater received both 1-year estimates 

and 3-year estimates. Most AIAN areas are small, and 

as a result, they will receive only 5-year estimates. 

 Table 3. Similarities and Diff erences Between the ACS and the Decennial Census Long-Form Survey

Year of Data Release

Data Population 2006 2007 2008 2009 2010 2011 2012 2013

product threshold 

 Year(s) of Data Collection

 1-year 

 estimates 65,000+ 2005 2006 2007 2008 2009 2010 2011 2012

 3-year 2005– 2006– 2007– 2008– 2009– 2010–

 estimates 20,000+ 2007 2008 2009 2010 2011 2012

 5-year 2005– 2006– 2007– 2008–

 estimates All areas* 2009 2010 2011 2012

Source: U.S. Census Bureau, American Community Survey Offi ce.

American Community Survey Decennial Census Long-Form Survey

Questionnaire Topics Cover numerous population and housing 

characteristics such as education, 

employment, disability, and veteran status. 

Cover numerous population and housing 

characteristics such as education, 

employment, disability, and veteran status.

Data Collection Continuous data collection takes place 

essentially every day of every year.

Data collection takes place over approximately 3–4 months during a census year.

Outreach and 

Promotion

Limited outreach is conducted to encourage 

participation, although information about 

the program is widely available through the 

Census Bureau.

Data collection takes place amidst the 

large promotion, advertising, and outreach 

campaign that accompanies the decennial 

census.

Residence Rule Persons living at the sample address for 

more than 2 months are included. 

Persons for whom the selected address 

represents their usual residence are included. 

Mandatory Response Response is required by law. Response is required by law.

Uses of Data Data are used to manage federal 

programs; state and local governments, 

nongovernment organizations, and the 

private sector also use the data.

Data are used to manage federal 

programs; state and local governments, 

nongovernment organizations, and the 

private sector also use the data.

Estimates ACS estimates represent data collection over 

12, 36, or 60 months. Data are known as 

“period estimates” because they correspond 

to a specifi c period of time.

Decennial census long-form sample estimates represent data collection over a few 

months around the time of the census. Data 

are known as “point in time” data because 

they are considered to represent a specifi c 

point in time, namely April 1, of a census 

year.

Data Products New data products are released each year. Data products are released following a census. 

New data are produced every 10 years.

 Table 2. Release Schedule for ACS Data

*Five-year estimates will be available for areas as small as census tracts and block groups. 

Source: U.S. Census Bureau.
6 What Users of Data for American Indians and Alaska Natives Need to Know 

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• Selected population profi les present detailed 

characteristics by race, ethnic, and tribal groups, 

as well as country of birth. This kind of ACS 

data product may be particularly useful to tribal 

governments because it provides information on 

many diff erent characteristics for a specifi c population group.

• Detailed tables provide access to a wealth of 

specifi c information on detailed characteristics, 

for example, sex by educational attainment for 

populations living in diff erent areas, including 

American Indian and Alaska Native areas. Many 

of the tables provide data iterated by race, for 

example, “sex by age by veteran status for the 

civilian population 18 years and older” for the 

population group “American Indian and Alaska 

Native Alone” and “geographical mobility in the 

past year by race” for the population “American 

Indian and Alaska Native Alone.”

• Thematic maps provide graphic displays of the 

data available through the geographic comparison 

tables. Variations in data across geographic areas 

are displayed. For some geographic areas, data 

users can highlight areas with statistically diff erent values from a selected area of interest. 

• Public Use Microdata Sample (PUMS) fi les 

are samples of individual records of people and 

households included in the ACS. The records are 

stripped of all identifying information, including 

address. The PUMS fi les permit analysis of specifi c 

population groups and custom variables that are 

not available through AFF. Multiyear PUMS fi les 

(based on 3- and 5-year estimates) may be used 

to produce data for relatively small population 

subgroups. If you wanted detailed characteristics 

of American Indians and Alaska Natives by type 

of occupation (for example, scientists and engineers), PUMS fi les would be of interest to you.

ACS Data Products

ACS Data for Geographic Areas

ACS data products are available through the 

American FactFinder (AFF) on the Census Bureau’s Web 

site: <http://factfi nder.census.gov>. Data are organized 

in two ways: as summary or aggregate data and as 

microdata. ACS data products are listed below.

• Data profi les provide tables summarizing social, 

economic, demographic, and housing characteristics for diff erent geographic areas, including 

American Indian and Alaska Native areas. Data 

profi les might be a good place to look for data 

if you were considering starting a local business 

and wanted to gain a broad picture of the sales 

potential for a particular kind of business, for 

example a bakery or sporting goods store, based 

on demographic, social, or economic information 

about households.

• Comparison profi les compare current-year estimates in the data profi les with estimates from the 

previous year and identify when diff erences in the 

estimates for two consecutive years are statistically diff erent.

• Ranking tables allow users to rank states, the 

District of Columbia, and Puerto Rico on over 80 

key characteristics, such as the percentage of 

the total population that are American Indian and 

Alaska Native alone. Ranking tables are available 

for single-year estimates. 

• Geographic comparison tables compare ACS 

data for a specifi c year across a variety of geographic areas other than states. A geographic 

comparison table can show how American Indian 

and Alaska Native areas vary in the proportion of 

the population having a particular characteristic, 

for example, speaking a language other than 

English at home.

• Subject tables provide information about a wide 

set of subjects, such as education, poverty, and 

housing. Some of these tables are available separately for the American Indian and Alaska Native 

populations. 

ACS data are provided for nearly all areas for which 

decennial census long-form data are available. These 

areas include states, counties, and incorporated places, 

such as cities and towns, as well as American Indian 

and Alaska Native governmental and statistical areas, 

such as American Indian Reservations, Alaska Native 

Village Statistical Areas, or Oklahoma Tribal Statistical Areas. The large majority of American Indian and 

Alaska Native areas have populations of less than 

20,000 and will therefore receive only 5-year data 

products. Detailed information about American Indian 

and Alaska Native areas for which ACS data are (or 
What Users of Data for American Indians and Alaska Natives Need to Know 7

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

will be) available is included in Appendix 1. Table 4 

lists the American Indian and Alaska Native areas for 

which ACS data are currently available as 1-year and/or 

3-year estimates. Alaska Native Regional Corporations, 

unique corporate entities established to conduct business with Alaska Natives, are listed separately. 

American Indian Area/Alaska Native Area 2007 

Estimates

2005–2007 

Estimates

Calista Alaska Native Regional Corporation x

Cook Inlet Alaska Native Regional Corporation x x

Doyon Alaska Native Regional Corporation x x

Sealaska Alaska Native Regional Corporation x x

Adais Caddo State Designated Tribal Statistical Area, LA x

Agua Caliente Indian Reservation and Off -Reservation Trust Land, CA x

Apache Choctaw State Designated Tribal Statistical Area, LA x

Cherokee Oklahoma Tribal Statistical Area, OK x x

Cherokees of Southeast Alabama State Designated Tribal Statistical Area, AL x x

Cheyenne-Arapaho Oklahoma Tribal Statistical Area, OK x x

Chickaloon Alaska Native Village Statistical Area, AK x

Chickasaw Oklahoma Tribal Statistical Area, OK x x

Choctaw Oklahoma Tribal Statistical Area, OK x x

Citizen Potawatomi Nation-Absentee Shawnee Oklahoma Tribal Statistical Area, OK x x

Coharie State Designated Tribal Statistical Area, NC x x

Creek Oklahoma Tribal Statistical Area, OK x x

Echota Cherokee State Designated Tribal Statistical Area, AL x x

Flathead Reservation, MT x

Four Winds Cherokee State Designated Tribal Statistical Area, LA x x

Isabella Reservation, MI x

Jena Band of Choctaw Tribal Designated Statistical Area, LA x x

Kaw/Ponca Joint-Use Oklahoma Tribal Statistical Area, OK x

Kenaitze Alaska Native Village Statistical Area, AK x

Kickapoo Oklahoma Tribal Statistical Area, OK x

Kiowa-Comanche-Apache-Fort Sill Apache Oklahoma Tribal Statistical Area, OK x x

Knik Alaska Native Village Statistical Area, AK x

Lumbee State Designated Tribal Statistical Area, NC x x

MaChis Lower Creek State Designated Tribal Statistical Area, AL x

Nanticoke Indian Tribe State Designated Tribal Statistical Area, DE x

Navajo Nation Reservation and Off -Reservation Trust Land, AZ–NM–UT x x

Oneida (WI) Reservation and Off -Reservation Trust Land, WI x

Osage Reservation, OK x

Puyallup Reservation and Off -Reservation Trust Land, WA x

Sac and Fox Oklahoma Tribal Statistical Area, OK x

Samish Tribal Designated Statistical Areas, WA x

Seminole Oklahoma Tribal Statistical Areas, OK x

Uintah and Ouray Reservation and Off -Reservation Trust Land, UT x

United Houma Nation State Designated Tribal Statistical Areas, LA x x

Wind River Reservation and Off -Reservation Trust Land, WY x

Yakama Nation Reservation and Off -Reservation Trust Land, WA x

 Table 4. American Indian and Alaska Native Areas for Which 1-Year (2007) and 3-Year (2005–2007) 

 ACS Estimates Have Been Released

Source: U.S. Census Bureau, American Community Survey Offi ce.
8 What Users of Data for American Indians and Alaska Natives Need to Know 

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Many data users are familiar with a fi xed 10-year cycle 

associated with decennial census data products. The 

ACS has a diff erent data tabulation cycle, and the data 

products have a diff erent look and feel from the longform decennial census data products that they are 

replacing. Some preparation may be helpful before you 

take a look at ACS data by logging on to the AFF. Here 

are some tips to remember:

The long form provides a snapshot; the ACS 

provides a moving picture

The decennial census is considered a snapshot of the 

population taken once every 10 years. In contrast, ACS 

data are collected continuously, and the data products represent a period of time ranging from 12 to 60 

months. The term “point-in-time” is frequently used 

to characterize decennial census data. Strictly speaking, of course, data collection for the decennial census 

takes place over a few months. But the data collected 

are associated with Census Day—April 1 of a census 

year. In contrast, the ACS “period estimates” cover 12, 

36, or 60 months of data collection and describe the 

average characteristics over that time period.

Selected population profi les and detailed tables: 

popular data products

Among ACS data products, the selected population 

profi les and detailed tables may be of most interest to 

you. For many applications, such as developing a broad 

picture of the characteristics of a tribe, or identifying 

specifi c characteristics suitable for use in a grant application, the selected population profi les and detailed 

tables are particularly useful. 

Margins of error are important

All estimates based on a sample include a range of 

uncertainty associated with them, and this range of 

uncertainty is described by the margin of error. If you 

have used data products from the decennial census 

long form in the past, you may have noticed that the 

information on margins of error did not appear on 

these tables. Instead, this information was provided 

separately from the tables, and data users had to calculate margins of errors for each estimate. Margins of 

error are important to consider when using data from 

the ACS, the decennial census long form, or any other 

survey. Margins of error that are too large may aff ect 

the usability of ACS data. 

The size of a group or area determines ACS data 

product viability and the level of detail provided

The availability of data for a specifi c population group 

will depend on the size of that population group or the 

population size of the geographic area of interest. For 

many topics, only national- and state-level data for the 

American Indian and Alaska Native population will be 

available as 1-year estimates because of the small population size of many American Indian and Alaska Native 

population groups. In addition to population, disclosure rules and confi dentiality thresholds can limit the 

availability of data for small groups and for areas with 

small populations. For example, for a selected population profi le, if fewer than 50 weighted sample cases 

are available for the selected population group, then 

data may not be released for that population group. 

An alternative way to present data for small tribes is to 

present it for the tribal grouping that comprises one or 

more tribes (for example, the Iroquois tribal grouping 

represents the Mohawk, Oneida Nation of New York, 

Seneca Nation, and other tribes). 

Fewer data are available for rare 

characteristics and small populations

The rarer and more detailed the characteristic, the less 

likely it is that data for that characteristic would be 

available for a small population group. There will be 

fewer data available for detailed characteristics, such 

as “households headed by females with children under 

18” than for more general characteristics, such as 

“households headed by females.”

Some ACS questions are asked only of 

specifi c groups

ACS data products cover the population in households 

and group quarters. However, just as was the case with 

some decennial census long-form questions, some ACS 

questions are limited to a specifi c population subgroup, such as the household population. Questions on 

housing characteristics, for example, are only asked of 

the household population. However, other questions, 

for example the question on language spoken at home, 

which provides information on populations that speak 

languages other than English, such as Winnebago, are 

asked of both the household and group quarters populations. 

Understanding ACS Data: Before You Log On to 

American FactFinder
What Users of Data for American Indians and Alaska Natives Need to Know 9

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

The Population Estimates Program, not the ACS, 

is the offi cial source of demographic estimates

Estimates of the American Indian and Alaska Native 

population for the nation, states, and counties are 

produced by the Census Bureau’s Population Estimates 

Program—the offi cial source of demographic estimates 

for these entities. ACS estimates for race and other key 

demographic variables are controlled to these estimates. The Population Estimates Program does not produce estimates by race for American Indian and Alaska 

Native areas. However, this program serves as a critical 

source of information for producing such estimates. 

Geographic boundaries are based on the latest 

information available

ACS data products for legal entities such as reservations and incorporated places refl ect the Census 

Bureau’s information about the legal boundaries for 

those entities as of January 1 of the year of data collection (or, as of January 1 of the last year of data collection for a multiyear data product). ACS data products 

for statistical areas such as State Designated Tribal 

Statistical Areas (SDTSAs) are based on the latest criteria and guidelines, usually refl ecting the last decennial 

census. Appendix 1 provides more information on the 

geography of ACS data products.

Accessing ACS Data Products

Getting started

Finding ACS data products starts with accessing AFF. 

If you are unfamiliar with AFF, use the AFF Site Tour to 

familiarize yourself with its features and options; the 

site tour is available at <http://factfi nder.census.gov

/home/en/epss/sitetour/topics.html>. 

• Log on to <www.census.gov> and click on 

“American FactFinder” (on the left side of the 

page). You will be directed to the “AFF Data Sets” 

page (see Figure 2). 

• Under the section titled “Getting Detailed Data,” 

select “American Community Survey—get data” 

(circled). This will direct you to the “ACS Data 

Sets” page, shown in Figure 3.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 2. The American FactFinder Data Sets Page
10 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• On the right column, you will see a list of data 

products from which to choose and will have the 

option to create a list of all tables and maps that 

are available, identify a table by its table number, 

and download PUMS data. To access a specifi c 

data product, you must select one of these 

options. 

• The “ACS Data Sets” page contains a description 

of the diff erent data sets that are available from 

the ACS. Note that several diff erent data sets are 

available; the fi rst data set listed is the 2005–

2007 ACS 3-year estimates. The most recently 

released ACS data set is considered the default 

ACS data set selection. In 2010, 2005–2009 ACS 

5-year estimates will be available. Data users can 

choose a diff erent data set by simply clicking on 

the radio button for that data set.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 3. ACS Data Sets Page

Example 1—Selected Population Profi les

For the fi rst exercise, we will identify a selected 

population profi le for a tribe, the Lumbee, for the 

nation. Persons identifying themselves as Lumbee 

live throughout the United States, and in relatively 

signifi cant numbers in North Carolina, where they 

have defi ned a State Designated Tribal Statistical Area 

(SDTSA) to represent an area of historic settlement. 

First, we will identify a national profi le of this tribe’s 

characteristics. That means that we will capture not 

only the characteristics of the Lumbee tribe living in 

this SDTSA, and throughout the state of North 

Carolina, but, additionally those of the Lumbee tribe 

living across the nation, whether in another American 

Indian or Alaska Native area, such as a reservation, or 

in a non-American Indian or Alaska Native area, such 

as a city or metropolitan or micropolitan statistical 

area. Once we have a national profi le, we will proceed 

to identify state profi les for this tribe.

Resuming the data access exercise started earlier:

• From the list of data products, highlight 

“Selected Population Profi les,” circled in 

Figure 3.

Data Product Examples
What Users of Data for American Indians and Alaska Natives Need to Know 11

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

 —You can select data for a single race or ethnic 

 group, such as “American Indian and Alaska 

 Native alone” or “Lumbee alone.”

 —Or you can select data for a race or ethnic 

 group in combination with one or more other 

 race and ethnic groups, such as “Navajo alone 

 or in any combination.”

For this exercise:

• Scroll down the list and select, “Lumbee alone 

or in any combination.”

• Click, “Show Result.” Figure 6 displays your 

selected population profi le.

The particular population or housing group covered 

by each data product is known as the universe. The 

universe for which the table in Figure 6 provides data 

is “Lumbee alone or in any combination” (circled).

• You are directed to the “Select Geography” page 

and asked to select a geographic type and one 

or more geographic areas (see Figure 4).

• Using the default selection method, “List,” select 

a geographic type using the drop-down menu. 

For this exercise, select “Nation,” the default 

selection.

 • “United States” appears in the geographic area 

box. 

• Click “Add,” so that “United States” then appears 

in the box of current geography selections. 

Figure 4 illustrates the choices you just made on 

the “Select Geography” page.

• Select “Next” to arrive at the “Select Population 

Groups” page, shown in Figure 5.

• The “Select Population Groups” page includes 

three tab selections, “Race or Ethnic Groups,” 

“Ancestry Groups,” and “Country of Birth.” Select 

“Race or Ethnic Groups,” then scroll down the 

list of choices. Note that two broad choices are 

off ered.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 4. American FactFinder Select Geography Page
12 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

teristic. For example, for the U.S. total population, 6.9 

percent of the population are under 5 and 6.4 percent 

of the population are ages 65–74. For the Lumbee, 8.0 

percent of the population are under 5 and 4.4 percent 

of the population are ages 65–74. 

The selected population profi le shows data for the 

total U.S. population and for the population group of 

interest side by side. This allows a data user to make 

a direct comparison between the population group of 

interest and the total population for a specifi c characSource: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 5. American FactFinder Select Population Groups Page

 Figure 6. Selected Population Profi le for the Lumbee Alone or in Any Combination 

 for the United States, 2005–2007 ACS 3-Year Estimates
What Users of Data for American Indians and Alaska Natives Need to Know 13

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• Using the drop-down menu, select “State,” then 

“North Carolina.”

Note that Figure 6 includes columns with information 

on margins of error. As described earlier, the margin of 

error around an estimate describes the precision of the 

estimate at a given level of confi dence. ACS estimates 

are associated with a 90-percent confi dence level. You 

should conduct statistical signifi cance tests with the 

information provided in the margin of error columns 

if you want to make comparisons. An example of how 

to conduct statistical testing is provided in Appendix 2; a 

comprehensive explanation of statistical testing is provided in Appendixes 3 and 4 of A Compass for Understanding and Using American Community Survey Data: 

What General Data Users Need to Know, accessible at 

<http://www.census.gov/acs/www/Downloads

/ACSGeneralHandbook.pdf>.

Let’s reconsider this example and attempt to identify 

a selected population profi le for the population group 

“Lumbee alone or in any combination” for a state 

instead of the nation.

• From the national selected population profi le 

for the “Lumbee alone or in any combination,” 

select a diff erent geography using the “Change” 

box in the left sidebar. Click on “Change geography.” You are directed to the “Select Geography” page.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 7. Selected Population Profi le for the Lumbee Alone or in Any Combination 

 for North Carolina, 2005–2007 ACS 3-Year Estimates

Why Is Information on Margins of Error 

Important? 

If you have used data products from the 

decennial census long form in the past, you 

may have noticed that margins of error do 

not appear on data product tables. Instead, 

information about sampling error was provided separate from the tables, and data users 

had to calculate margins of errors themselves. 

Users of Census 2000 long-form data products were often unaware of the importance of 

margins of error. As a result, they often used 

decennial census long-form data as if these 

data represented a count or enumeration of 

persons with specifi c characteristics, rather 

than an estimate based on a sample. Margins 

of error are provided for every ACS estimate 

with 90 percent certainty (this is the 90-percent confi dence level). 
14 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Let’s try to identify a comparable profi le for the Lumbee 

for another state:

• Using the same procedure described to obtain 

a selected population profi le for North 

Carolina, use the “Change” box in the left 

sidebar and click “Change geography.” You are 

directed to the “Select Geography” page.

• From the drop-down menus, select “State,” then 

select “South Carolina.” 

• Click “Add.” Remove “North Carolina” from the 

current geography selections box. 

• Next, click “Show Result” to obtain the information shown in Figure 8. 

You expect to see a selected population profi le for 

“Lumbee population alone or in any combination” for 

South Carolina. However, instead of a table, AFF provides a title for the table you expected to see, followed 

by a note stating that data are not available for the 

selected geography. You are directed to change your 

selection to a larger geography to view a table for the 

selected population group. 

This note appears when the available data do not 

make it possible for AFF to provide a particular table of 

choice. In this case, the 20,000-population threshold 

required for ACS 3-year estimates is met by both the 

national and the North Carolina profi les for the 

“Lumbee alone or in any combination” population, but 

not for a comparable profi le for South Carolina. As a 

result, AFF did not provide a table showing a selected 

population profi le for the “Lumbee alone or in any 

combination” for South Carolina based on 2005–2007 

ACS 3-year estimates.

• Click “Add.” The current geography selections 

box should now contain two choices, “United 

States” and “North Carolina.” 

• Next, click “Show Result” to obtain the table 

shown in Figure 7 (scroll down through the fi rst 

table for the United States to see the table for 

North Carolina). 

• If you want to see the table for North Carolina 

alone, without the table for the United States, 

then remove the choice “United States” from 

the current geography selections box before 

selecting “Show Result.” Figure 4 illustrates the 

“Remove” option that is used to limit the choice 

of current geography selections. By removing United States as a choice, the resulting 

table will only provide data for North Carolina. 

Experiment with some of the options described 

in this and other sets of instructions to become 

familiar with their use. Also, you may wish to 

try printing a few of the tables to understand 

the usability of AFF selections as hard-copy 

handouts for conferences or similar events. It 

may not be cost-eff ective or appropriate to print 

large quantities of such documents because of 

their size. For example, when printed without 

modifying the font size or other features and 

using 8.5 x 11-inch paper, a selected population 

profi le is seven pages in length. 

Comparing Figures 6 and 7, we can identify how the 

Lumbee population in North Carolina diff ers from the 

Lumbee population nationally and from the total population, nationally, for North Carolina and for the United 

States. 

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 8. Results of Attempting to Obtain a Selected Population Profi le for the 

 Lumbee Alone or in Any Combination for South Carolina Based on 

 2005–2007 ACS 3-Year Estimates
What Users of Data for American Indians and Alaska Natives Need to Know 15

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• Use the default selection method, “List,” and 

then, from the geographic type drop-down 

menu, select “American Indian Area/Alaska 

Native Area/Hawaiian Home Land.” 

• Scroll down the list of specifi c geographies and 

select “Chickasaw OTSA, OK.” Click “Next.”

You will be directed to a page to select one or more 

tables associated with a specifi c subject (see Figure 10). 

• Use the drop-down menu for “List tables by 

subject,” (identifi ed by a circle) to view a list of 

tables by subject.

• Select “Transportation,” then “Go.” Three subject 

tables are identifi ed, as shown in Figure 11. 

• Select “Means of Transportation to Work by 

Selected Characteristics.”

• Figure 12 displays your requested subject table 

for Chickasaw OTSA, OK.

Example Two—Subject Tables

Subject tables summarize information on a range of 

characteristics that pertain to a particular subject, for 

example, disability, education, employment, aging, and 

children. In this example, we will fi nd data on modes 

of transportation for the American Indian and Alaska 

Native population in an Oklahoma Tribal Statistical Area 

(OTSA). The Department of Transportation uses ACS 

data on modes of transportation to identify needs for 

public transportation and new roads and to identify 

needs for transportation funding to support goals 

such as new transit services for elderly and disabled 

populations.

If you are navigating from one example to the next in 

this document by using the back arrow at the top left 

corner, you should click “Clear all selections” (circled) 

on the “ACS Data Sets” page before proceeding to a 

new example (see Figure 9).

• From the “ACS Data Sets” page, select 2005–

2007 American Community Survey 3-Year 

Estimates, and “Subject Tables” from the list of 

ACS data products. You are then directed to the 

“Select Geography” page.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 9. Clearing Selections in American FactFinder
16 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 10. American FactFinder Subject Tables Page

 Figure 11. Using the Subject Tables Menu in American FactFinder
What Users of Data for American Indians and Alaska Natives Need to Know 17

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• From the AFF “ACS Data Sets” page, clear all 

selections, then select 2005–2007 ACS 3-year 

estimates. 

• Select “Detailed Tables” from the list of ACS 

data product options.

• On the “Select Geography” page, use the “name 

search” option since you know the name of the 

geographic area of interest. Select the geographic type, “American Indian Area/Alaska 

Native Area/Hawaiian Home Land,” and enter 

“Navajo Reservation” in the “Enter name to 

search for” box.

• Select “Search” and a list of specifi c geographic 

areas will appear. For this example, the only 

geographic area corresponding to a “name 

search” entry of “Navajo Reservation” is 

“Navajo Nation Reservation and 

Off -Reservation Trust Land, AZ-NM-UT.” 

• Click “Add,” then “Next.” 

Figure 12 provides information on means of transportation, including the proportion of workers using cars, 

trucks, or vans driving alone, in carpools, or by public 

transportation. Note that data are available for the race 

category “American Indian and Alaska Native.” The 

margins of error for several characteristics for the race 

“American Indian and Alaska Native” are relatively large 

because the estimate of the population for this race for 

the Chickasaw OTSA is relatively small and because the 

number of persons estimated to have any particular 

characteristic for this population group is relatively 

small. When 5-year estimates are available, the margins 

of error will be smaller, and the data will be more useful as a result. 

Example 3—Detailed Tables

Another example of an ACS data product is the detailed 

table. For this example we want to fi nd information 

about educational attainment for the Navajo Nation 

Reservation and Off -Reservation Trust Land, AZ-NM-UT.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 12. Means of Transportation to Work by Selected Characteristics for 

 Chickasaw Oklahoma Tribal Statistical Area, OK, 2005–2007 

 ACS 3-Year Estimates
18 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Detailed tables are useful for providing estimates for 

a particular variable by one or more demographic 

characteristics, in this case, educational attainment by 

age and sex. This kind of information can be used to 

identify a target population for which the characteristics could have important implications for tribal planning. For example, educational attainment levels less 

than “high school graduate” may attest to a need for 

adult education. Conversely, a population for which a 

large percentage has completed high school may prove 

attractive to businesses or to tribal planners interested 

in attracting economic development. 

Example 4—Working With AFF Features

Using AFF involves navigating data sets with a variety 

of features and options that are displayed in pull down 

menus and links. In this example, we will illustrate 

one of those features, the “geographic components” 

option, to fi nd information for diff erent geographic 

components of the American Indian and Alaska Native 

population.

• From the AFF “ACS Data Sets” page, clear all 

selections, then select 2005–2007 ACS 3-Year 

Estimates. 

• Select “Detailed Tables” from the list of ACS data 

product options.

• On the “Select Geography” page, use the default 

selection method, “List.” Once the geographic 

area “United States” appears, click “Add,” then 

“Next.”

• Identify the specifi c detailed table of interest. If you select the “by keyword” tab, enter 

“educational attainment” and click “Search.” 

You will get a shorter list of tables from which 

to choose. 

• For this exercise, select “Sex by Educational 

Attainment for the Population 25 Years and 

Over” for the population group, “American 

Indian and Alaska Native Alone.” Note that two 

versions of the table are available, one with a 

prefi x of B, and the other with prefi x of C (see 

Figure 13, where the two versions of the same 

table are circled). 

If you don’t know the signifi cance of those prefi xes, 

you should select the link “explain table numbers” 

to fi nd out. The leading “B” designates basic or base 

tables that provide the most detailed estimates. The 

leading “C” means that the table will represent a collapsed version of the B table. By collapsing categories, 

detailed groups are combined into fewer categories, 

and the Census Bureau can present information that is 

less detailed and therefore more reliable. Sometimes it 

is a good idea to select “B” and “C” versions so you can 

review both to see which is better for your needs.

• Once you have identifi ed one or more tables, 

add them to the selection box, then select 

“Show Result.” 

• Figure 14 shows a portion of a basic, or “B” 

table, meaning that it refl ects the most detail 

that is possible to present for this table. 

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 13. Base and Collapsed Tables
What Users of Data for American Indians and Alaska Natives Need to Know 19

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

• Urban

• Rural

• In metropolitan or micropolitan statistical area

• Not in metropolitan or micropolitan statistical 

area

• In metropolitan statistical area

• In metropolitan statistical area—in principal city

• In metropolitan area—not in principal city

• Not in metropolitan statistical area

• In micropolitan statistical area

• In micropolitan area—in principal city

• In micropolitan area—not in principal city

Which geographic component(s) should you choose? At 

fi rst glance, it might seem that choosing to see a data 

product for the “Urban” population would meet your 

needs. However, for many data users, “In metropolitan 

statistical area” or “In metropolitan or micropolitan 

statistical area” may be more useful geographic units of 

analysis. A metropolitan statistical area contains a core 

urban area of 50,000 or more population, and a 

micropolitan area contains an urban core of at least 

10,000 (but less than 50,000) population. Each 

metropolitan or micropoltan statistical area consists of 

• Using the default selection method “show all 

tables,” scroll through the list of tables and 

select Table C17001C, “Poverty Status in the 

Past 12 Months by Sex by Age (American Indian 

and Alaska Native Alone)” to obtain the collapsed version of the table. 

• Click “Add,” then “Show Result,” to obtain the 

table shown in Figure 15. This table provides 

estimates of the number of males and females 

who reported a race of “American Indian and 

Alaska Native alone” by broad age groups, with 

income in the past 12 months below the poverty level.

Suppose we would like to see this table for one of a 

number of broad geographic components of the United 

States so we can distinguish characteristics of the 

urban American Indian and Alaska Native population. 

Point to the “Options” link near the top of the page, 

then scroll down to select “Geo Components.” You are 

then directed to another series of choices in a dropdown menu that includes the following broad geographic categories:

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 14. Sex by Educational Attainment for the Population 25 Years and Over 

 (American Indian and Alaska Native Alone) for the Navajo Nation 

 Reservation and Off -Reservation Trust Land, AZ–NM–UT, 2005–2007 

 ACS 3-Year Estimates
20 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 15. Poverty Status in the Past 12 Months by Sex and by Age (American Indian 

 and Alaska Native Alone) for the United States, 2005–2007 ACS 3-Year 

 Estimates 

 Figure 16. Poverty Status in the Past 12 Months by Sex and by Age (American Indian 

 and Alaska Native Alone) for the United States and for Metropolitan 

 Statistical Areas in the United States, 2005–2007 ACS 3-Year Estimates
What Users of Data for American Indians and Alaska Natives Need to Know 21

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

consider your needs, or the preferences or requirements of the program or application for which you are 

providing data. For this example, we will distinguish 

urban characteristics for the American Indian and 

Alaska Native alone population by choosing the geographic component “In metropolitan statistical area.” 

• Select “In metropolitan statistical area” from 

among the geographic components listed.

• Select “Add,” then “OK,” to be directed to a new 

table, a portion of which is shown in Figure 16.

By comparing statistics for the American Indian and 

Alaska Native alone population in the United States 

to those for the population in metropolitan statistical areas in the United States, one can identify more 

specifi cally which characteristics are diff erent. The differences in characteristics may point to diff erent needs 

for services based on the diff erences in the characteristics for the two populations. 

one or more counties and includes the counties containing the core urban area, as well as adjacent counties that have a high degree of social and economic 

integration (as measured by commuting to work) with 

the urban core. The Census Bureau’s current urban/

rural defi nitions are block and block group based. 

In contrast, metropolitan and micropolitan areas 

are defi ned on the basis of a larger geographic area 

(county) for which there is a greater availability of data 

and for which data tabulations are easier to use. Metropolitan and micropolitan statistical areas are not proxies for the urban population; many counties included 

in metropolitan and micropolitan areas, and many 

other counties, contain both urban and rural territory 

and populations. However, depending on the requirements of the data user, metropolitan statistical areas or 

metropolitan and micropolitan statistical areas may be 

the units of analysis that meet the data user’s needs. In 

considering which geographic component to use, 

How Will Federal Agencies Use ACS Data 

to Benefi t American Indians and Alaska 

Natives?

Federal agencies will use ACS data to manage 

programs providing services such as education, health care, transportation, and housing to American Indians and Alaska Natives. 

For example, the Offi ce of Native American 

Programs at the Department of Housing and 

Urban Development (HUD) will use ACS data 

on population, income, and the physical 

characteristics of housing to implement the 

Indian Housing Block Grant Program. That 

program provides low-income American Indian 

and Alaska Native households with housingrelated services such as new construction and 

housing rehabilitation. HUD will use ACS data 

on rent to determine fair market rents that 

serve as benchmarks for HUD’s evaluation of 

rental costs and the basis for providing rent 

assistance. ACS data on persons per housing 

unit will be used to identify overcrowding and 

potential needs for new housing, water, and 

sewer facilities.

Using ACS Data

You will usually need a combination of data resources 

that may include ACS data to identify needs for services, 

apply for grants, or make the case for changes in public policy. ACS data alone may not be suffi cient; other 

sources of information are needed to supplement the 

ACS. For example, a tribal government planner might 

take advantage of the following information resources 

to come up with an economic development plan:

• ACS data on characteristics of the population 

(a selected population profi le) to identify a 

potential workforce and customer base from 

among those living on or near the reservation.

• The Census Bureau’s County Business Patterns 

data to identify unmet needs for new services 

or retail establishments.

• The Census Bureau’s Census Information Center 

to learn more about how to use all of the 

Census Bureau’s information resources.

• Local Chamber of Commerce information on 

the history of business establishments in the 

area.

• Information on business loan opportunities 

from local or regional banks or the Small 

Business Administration.

• Information from national advocacy organizations on grant programs providing funding for 

child care services.

• Information on business products or services 

from the private sector.

• Courses on business skills off ered through 

a tribal college or other institution of higher 

learning.

Federal agencies will use ACS data for a variety of programs that currently rely on data from the decennial 

census long form. These programs provide services 

such as health care, education, and job training. 
22 What Users of Data for American Indians and Alaska Natives Need to Know 

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

It may take some time to become familiar with ACS 

data. Here are some rules of the road. 

Use the right terminology

ACS 3-year estimates based on data collected from 

2005–2007 should not be called “2006” or “2007” estimates. Nor should 2005–2009 ACS 5-year estimates be 

labeled “2007” estimates, even though that is the midpoint of the 5-year period. Multiyear estimates should 

be labeled to indicate clearly the full period of time 

they represent (for example, “The rate of homeownership in 2005–2007 was X percent.”) 

Consider your needs if you have a choice of 

estimates to use 

As a general rule, unless you have a compelling need 

for the most current data, choose multiyear estimates 

over single-year estimates. Single-year estimates (also 

called 1-year estimates) provide more current information. However, multiyear estimates are based on 

larger sample sizes and will therefore be more reliable, 

particularly for smaller geographic areas and small 

population subgroups. If we compare the estimates 

in Figures 17 and 18, it is clear that the margins of 

error are larger for the 1-year estimates. You might 

conclude that using the 3-year estimates would be the 

right choice, even though you have a preference for 

the more current information refl ected by the 1-year 

estimates. What other information could you consider 

in making a decision about which estimate to use?

If you want to weigh the benefi ts of using multiyear 

estimates over single-year estimates, or using 5-year 

estimates over 3-year estimates, consider information 

about the magnitude of the coeffi cient of variation (CV) 

in making your decision. CVs are measures that can 

be used to judge the level of reliability of an estimate. 

These measures are constructed using information on 

the margin of error (MOE) for the estimate, and the 

value 1.645, which represents the factor corresponding 

to the 90-percent confi dence level associated with ACS 

estimates. Calculate the CV using the steps below.

• First, calculate the standard error (SE) for the 

estimate: SE = MOE/1.645.

• Next, calculate the coeffi cient of variation (CV) 

for the estimate: CV = SE/Estimate x 100%.

We want to determine the benefi t of using a 3-year estimate for renter-occupied units for the American Indian 

and Alaska Native population on the Navajo Nation 

Reservation and Off -Reservation Trust Land (shown in 

Figure 17) over a 1-year estimate for this characteristic 

for the same population in the same geographic area 

(shown in Figure 18). 

Rules of the Road

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 17. Tenure for the American Indian and Alaska Native Alone Householder, 

 Navajo Nation Reservation and Off -Reservation Trust Land, AZ-NM-UT, 

 2005–2007 ACS 3-Year Estimates
What Users of Data for American Indians and Alaska Natives Need to Know 23

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

high CVs. What is needed instead is the most credible 

and statistically reliable data, so using ACS estimates 

with the lower CVs would be the right choice. 

Using ACS estimates to measure change

One of the important uses of ACS data will be to identify change in communities and populations. Be aware 

that annual fl uctuations in data for 1-year estimates do 

not necessarily constitute change. Use the information 

on margins of error to perform tests of statistical signifi cance before drawing conclusions about diff erences 

between two estimates. When using multiyear estimates to identify change, as a general rule, it is better 

to compare estimates that do not overlap. Consider a 

comparison of two 3-year estimates, one representing the period 2005–2007 and the other representing 

the period 2006–2008. The two sets of estimates are 

unlikely to diff er because 2 of the 3 years overlap (both 

sets of estimates include the same data collected in 

2006 and 2007). The overlap is even greater for two 

consecutive 5-year estimates; for example, 4 of the 5 

years overlap when you are comparing estimates from 

the 2005 to 2009 ACS to estimates from the 2006 

to 2010 ACS. The Census Bureau generally suggests 

comparing estimates for periods that do not overlap—

comparing 2005–2007 estimates with 2008–2010 

estimates, for example. Comparisons of overlapping 

5-year estimates can be useful but need to be undertaken with caution. Specifi c information about dealing 

with overlapping estimates can be found in Appendix 4 

• For the 3-year estimate, SE = 626/1.645, or 

380.5, and the CV = 380.5/8093 x 100, or 4.7 

percent.

• For the 1-year estimate, SE = 1017/1.645, or 

618.2, and the CV = 618.2/7814 x 100, or 7.9 

percent.

There are no hard and fast rules about when a CV is 

considered “too high.” This will be driven by the specifi c application. Some data users have suggested that 

estimates with CVs of 15 percent or more should be 

viewed with caution. For this example, both the 1-year 

and 3-year estimates for renter-occupied units have 

CVs that are well under 15 percent, so either estimate 

can be used with confi dence. If the 1-year estimate had 

exceeded 15 percent, then using the 3-year estimate 

might have been the better choice. For this example, 

there seems to be little advantage in using the 3-year 

estimate over the 1-year estimate, so, in the interest 

of using the more current data, the choice would be to 

use the 1-year estimate. 

This example illustrates that while statistically reliable 

3-year estimates might seem preferable, currency of 

data may outweigh that benefi t in special situations. 

For example, currency of data is often very important 

in marketing. Even slight evidence of change in a community might provide a competitive advantage in marketing a new product or service. On the other hand, it 

might be risky to implement a costly new government 

policy or program based on current estimates having 

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 18. Tenure for the American Indian and Alaska Native Alone Householder, 

 Navajo Nation Reservation and Off -Reservation Trust Land, AZ-NM-UT, 

 2007 ACS 1-Year Estimates
24 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

(for example, American Indian and Alaska Native alone 

or American Indian and Alaska Native in combination 

with one or more other races) or limited to a particular 

tribe (for example, Sioux alone, or Sioux alone or in 

combination). When you are making comparisons, be 

certain you are comparing equivalent universes. 

When comparing, use estimates for the same 

data collection period

Suppose you are responsible for developing and 

administering a grant program. How would you 

instruct potential grant applicants regarding what kind 

of data are acceptable? You should require that all 

potential applicants use the same kind of estimate (for 

example, requiring everyone to submit data based on 

a 5-year estimate, rather than allowing some applicants to use single-year estimates and others to use 

3- or 5-year estimates). In addition, applicants should 

be required to use estimates representing the same 

period of time (e.g., requiring that all applicants use 

the 5-year estimate for a specifi c period, for example, 

2008–2012, rather than allowing applicants to submit 

data representing any 5-year period estimate). The 

same approach should be used in comparing estimates 

for one area to those for another area. Suppose you 

wanted to compare characteristics for one reservation, for which both 3-year and 5-year estimates are 

available, to those for a smaller reservation, for which 

only 5-year estimates are available. You should compare 2005–2009 ACS 5-year estimates for the smaller 

reservation with 2005–2009 ACS 5-year estimates for 

the larger reservation, even though more recent 3-year 

estimates are available for the larger reservation.

of A Compass for Understanding and Using American 

Community Survey Data: What General Data Users 

Need to Know at <http://www.census.gov/acs

/www/Downloads/ACSGeneralHandbook.pdf>. Data 

users also need to use caution in looking at trends 

involving income or other measures that are adjusted 

for infl ation, such as rental costs, home values, and 

energy costs. Appendix 5 of the General Data Users 

handbook provides information on the adjustment of 

single-year and multiyear ACS estimates for infl ation. 

Comparing ACS data with other data sets

Some ACS data items are comparable with Census 

2000 long-form data items, while others are not, and 

still others are comparable under certain conditions or 

restrictions. Compare ACS data to Census 2000 longform data based on guidance provided at 

<http://www.census.gov/acs/www/UseData

/compACS.htm>. ACS data will diff er from many kinds 

of administrative data maintained by tribal governments, such as tribal enrollment records. Diff erences 

in reference periods, question wording, sample design, 

and data collection can all account for diff erences in 

data collected for two diff erent surveys, diff erences 

between data collected for a survey and data collected 

for a census, or diff erences in data collected for a survey and data from administrative records.

Use the right universe 

To distinguish the characteristics of the population 

by race, one needs to use an ACS table for which the 

universe (population group of interest) is limited to the 

American Indian and Alaska Native alone population 

Interpreting ACS Data for American Indian and Alaska Native Areas

ACS data users need to be especially cautious when interpreting ACS data for American Indian 

areas and Alaska Native areas. Many such areas have substantial populations that are neither 

American Indian nor Alaska Native. Socioeconomic or other characteristics for non-American Indian 

and non-Alaska Native populations may diff er, and markedly so, from those for American Indian 

and Alaska Native populations. When ACS tables are iterated by race, such as in the case of the 

subject table portrayed in Figure 12, diff erences can be easily noted for these two populations. 

However, many ACS tables for American Indian areas and Alaska Native areas do not provide iterations by race for the characteristics for which the table provides data. For example, 2005–2007 

ACS data profi les for Flathead Reservation, Montana, or Chickaloon Alaska Native Village Statistical 

Area, Alaska, do not provide characteristics data iterated by race. The universe for the tables is the 

total population. It would be incorrect to interpret an economic indicator such as poverty rate or 

a social indicator such as school enrollment rate for an American Indian or Alaska Native area as 

describing the characteristics of the American Indian or Alaska Native population.
What Users of Data for American Indians and Alaska Natives Need to Know 25

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Data users can fi nd additional information about the 

ACS on the Census Bureau’s ACS Web site, <http://

www.census.gov/acs/www/>. Guidance on the latest 

data products is available at <http://www.census.gov

/acs/www/Products/index.html>. AFF help is available 

at <http://factfi nder.census.gov/home/en/epss

/main.html>. Finally, the ACS Compass Products 

include a series of handbooks (including this handbook) that provide information on understanding and 

using ACS data targeted to specifi c audiences. They 

can be found at <http://www.census.gov/acs/www

/UseData/Compass/compass_series.html>.

From time to time, the Census Bureau develops special 

reports or fi les based on data collected in surveys and 

censuses, including the ACS. One fi le that is planned 

will focus on information on population and housing 

data for American Indians and Alaska Natives collected 

on a sample basis by the ACS. This fi le is designed to 

be similar to Census 2000 American Indian and Alaska 

Native Summary File (AIANSF)—Sample Data, a Census 

2000 fi le that iterates data for the total population, the 

total American Indian and Alaska Native population, 

the total American Indian population, the total Alaska 

Native population, and for additional specifi ed 

American Indian and Alaska Native tribes. 

Other Resources for Working With ACS Data

The Census Bureau’s American Indian and 

Alaska Native Web Portal

Conclusion

You will fi nd information about ACS as well as other 

Census Bureau products focusing on data for 

American Indians and Alaska Natives on <http://

factfi nder.census.gov/home/aian/index.html>, 

the general portal for all information of interest to 

users of census data on American Indians and Alaska 

Natives. You may wish to bookmark this site. In addition to information on data products, the site includes 

information on the Census Bureau’s Advisory Committee for American Indians and Alaska Natives and 

other federal sources of information on American 

Indians and Alaska Natives. 

Readers of this handbook will fi nd that it is important 

to learn how to use and interpret ACS data. For many, 

the focus of interest will be the 5-year estimates, 

which will not be available until late 2010. The Census 

Bureau is off ering a great deal of information on data 

products to ACS data users. In addition, the Census 

Bureau is seeking to help data users learn more about 

data products such as PUMS fi les that may be unfamiliar to them but that off er great potential for expanding 

the use of ACS data for American Indians and Alaska 

Natives. 

The Census Bureau has embarked on a bold mission in 

developing the ACS. An understanding of the ACS data 

products is critical to take full advantage of the availability of these important data. The Census Bureau’s 

Regional Offi ces and Census Bureau headquarters 

staff , as well as our partners in the State Data Centers 

and the Census Information Centers, are ready to help 

users of ACS data for American Indians and Alaska 

Natives embrace the learning process. 

What Users of Data for American Indians and Alaska Natives Need to Know 27

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Glossary

Accuracy. One of four key dimensions of survey 

quality. Accuracy refers to the diff erence between 

the survey estimate and the true (unknown) value. 

Attributes are measured in terms of sources of error 

(for example, coverage, sampling, nonresponse, 

measurement, and processing). 

American Community Survey Alert. This periodic 

electronic newsletter informs data users and other 

interested parties about news, events, data releases, 

congressional actions, and other developments 

associated with the ACS. See <http://www.census

.gov/acs/www/Special/Alerts/Latest.htm>.

American FactFinder (AFF). An electronic system 

for access to and dissemination of Census Bureau 

data on the Internet. AFF off ers prepackaged data 

products and user-selected data tables and maps 

from Census 2000, the 1990 Census of Population 

and Housing, the 1997 and 2002 Economic 

Censuses, the Population Estimates Program, annual 

economic surveys, and the ACS. 

Block group. A subdivision of a census tract (or, 

prior to 2000, a block numbering area), a block 

group is a cluster of blocks having the same fi rst 

digit of their four-digit identifying number within 

a census tract. 

Census geography. A collective term referring 

to the types of geographic areas used by the 

Census Bureau in its data collection and tabulation 

operations, including their structure, designations, 

and relationships to one another. See <http://www

.census.gov/geo/www/index.html>.

Census tract. A small, relatively permanent 

statistical subdivision of a county delineated by a local 

committee of census data users for the purpose of 

presenting data. Census tract boundaries normally 

follow visible features, but may follow governmental 

unit boundaries and other nonvisible features; they 

always nest within counties. Designed to be relatively 

homogeneous units with respect to population 

characteristics, economic status, and living conditions 

at the time of establishment, census tracts average 

about 4,000 inhabitants. 

Coeffi cient of variation (CV). The ratio of the 

standard error (square root of the variance) to the 

value being estimated, usually expressed in terms 

of a percentage (also known as the relative standard 

deviation). The lower the CV, the higher the relative 

reliability of the estimate. 

Comparison profi le. Comparison profi les are 

available from the American Community Survey for 

1-year estimates beginning in 2007. These tables 

are available for the U.S., the 50 states, the District of 

Columbia, and geographic areas with a population of 

more than 65,000.

Confi dence interval. The sample estimate and its 

standard error permit the construction of a confi dence 

interval that represents the degree of uncertainty about 

the estimate. A 90-percent confi dence interval can be 

interpreted roughly as providing 90 percent certainty 

that the interval defi ned by the upper and lower 

bounds contains the true value of the characteristic. 

Confi dentiality. The guarantee made by law (Title 

13, United States Code) to individuals who provide 

census information, regarding nondisclosure of that 

information to others. 

Consumer Price Index (CPI). The CPI program of 

the Bureau of Labor Statistics produces monthly data 

on changes in the prices paid by urban consumers for 

a representative basket of goods and services.

Controlled. During the ACS weighting process, the 

intercensal population and housing estimates are used 

as survey controls. Weights are adjusted so that ACS 

estimates conform to these controls. 

Current Population Survey (CPS). The CPS is 

a monthly survey of about 50,000 households 

conducted by the Census Bureau for the Bureau of 

Labor Statistics. The CPS is the primary source of 

information on the labor force characteristics of the 

U.S. population.

Current residence. The concept used in the ACS to 

determine who should be considered a resident of a 

sample address. Everyone who is currently living or 

staying at a sample address is considered a resident of 

that address, except people staying there for 2 months 

or less. People who have established residence at the 

sample unit and are away for only a short period of 

time are also considered to be current residents. 

Custom tabulations. The Census Bureau off ers a 

wide variety of general purpose data products from the 

ACS. These products are designed to meet the needs 

of the majority of data users and contain predefi ned 
28 What Users of Data for American Indians and Alaska Natives Need to Know

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

sets of data for standard census geographic areas, 

including both political and statistical geography. 

These products are available on the American 

FactFinder and the ACS Web site.

For users with data needs not met through the general 

purpose products, the Census Bureau off ers “custom” 

tabulations on a cost-reimbursable basis, with the 

American Community Survey Custom Tabulation 

program. Custom tabulations are created by tabulating 

data from ACS microdata fi les. They vary in size, 

complexity, and cost depending on the needs of the 

sponsoring client.

Data profi les. Detailed tables that provide 

summaries by social, economic, and housing 

characteristics. There is a new ACS demographic and 

housing units profi le that should be used if offi cial 

estimates from the Population Estimates Program are 

not available.

Detailed tables. Approximately 1,200 diff erent 

tables that contain basic distributions of characteristics. These tables provide the most detailed data and 

are the basis for other ACS products.

Disclosure avoidance (DA). Statistical methods 

used in the tabulation of data prior to releasing data 

products to ensure the confi dentiality of responses. 

See Confi dentiality. 

Estimates. Numerical values obtained from a 

statistical sample and assigned to a population 

parameter. Data produced from the ACS interviews are 

collected from samples of housing units. These data 

are used to produce estimates of the actual fi gures that 

would have been obtained by interviewing the entire 

population using the same methodology. 

File Transfer Protocol (FTP) site. A Web site that 

allows data fi les to be downloaded from the Census 

Bureau Web site.

Five-year estimates. Estimates based on 5 years of 

ACS data. These estimates refl ect the characteristics 

of a geographic area over the entire 5-year period and 

will be published for all geographic areas down to the 

census block group level.

Geographic comparison tables. More than 80 

single-variable tables comparing key indicators for 

geographies other than states.

Geographic summary level. A geographic summary 

level specifi es the content and the hierarchical 

relationships of the geographic elements that are 

required to tabulate and summarize data. For example, 

the county summary level specifi es the state-county 

hierarchy. Thus, both the state code and the county 

code are required to uniquely identify a county in the 

United States or Puerto Rico. 

Group quarters (GQ) facilities. A GQ facility is a 

place where people live or stay that is normally owned 

or managed by an entity or organization providing 

housing and/or services for the residents. These 

services may include custodial or medical care, as well 

as other types of assistance. Residency is commonly 

restricted to those receiving these services. People 

living in GQ facilities are usually not related to each 

other. The ACS collects data from people living in both 

housing units and GQ facilities.

Group quarters (GQ) population. The number of 

persons residing in GQ facilities. 

Item allocation rates. Allocation is a method 

of imputation used when values for missing or 

inconsistent items cannot be derived from the existing 

response record. In these cases, the imputation 

must be based on other techniques such as using 

answers from other people in the household, other 

responding housing units, or people believed to have 

similar characteristics. Such donors are refl ected in a 

table referred to as an allocation matrix. The rate is 

percentage of times this method is used.

Margin of error (MOE). Some ACS products provide 

an MOE instead of confi dence intervals. An MOE is the 

diff erence between an estimate and its upper or lower 

confi dence bounds. Confi dence bounds can be created 

by adding the margin of error to the estimate (for the 

upper bound) and subtracting the margin of error from 

the estimate (for the lower bound). All published ACS 

margins of error are based on a 90-percent confi dence 

level. 

Multiyear estimates. Three- and fi ve-year estimates 

based on multiple years of ACS data. Three-year 

estimates will be published for geographic areas with 

a population of 20,000 or more. Five-year estimates 

will be published for all geographic areas down to the 

census block group level. 

Narrative profi le. A data product that includes easyto-read descriptions for a particular geography. 

Nonsampling error. Total survey error can be 

classifi ed into two categories—sampling error and 

nonsampling error. Nonsampling error includes 

measurement errors due to interviewers, respondents, 

instruments, and mode; nonresponse error; coverage 

error; and processing error.
What Users of Data for American Indians and Alaska Natives Need to Know 29

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Period estimates. An estimate based on information 

collected over a period of time. For ACS the period is 

either 1 year, 3 years, or 5 years.

Point-in-time estimates. An estimate based on 

one point in time. The decennial census long-form 

estimates for Census 2000 were based on information 

collected as of April 1, 2000.

Population Estimates Program. Offi cial Census 

Bureau estimates of the population of the United 

States, states, metropolitan areas, cities and towns, 

and counties; also offi cial Census Bureau estimates of 

housing units (HUs). 

Public Use Microdata Area (PUMA). An area that 

defi nes the extent of territory for which the Census 

Bureau releases Public Use Microdata Sample (PUMS) 

records. 

Public Use Microdata Sample (PUMS) fi les. 

Computerized fi les that contain a sample of individual 

records, with identifying information removed, 

showing the population and housing characteristics of 

the units, and people included on those forms. 

Puerto Rico Community Survey (PRCS). The 

counterpart to the ACS that is conducted in Puerto 

Rico. 

Quality measures. Statistics that provide information 

about the quality of the ACS data. The ACS releases 

four diff erent quality measures with the annual data 

release: 1) initial sample size and fi nal interviews; 

2) coverage rates; 3) response rates, and; 4) item 

allocation rates for all collected variables. The ACS 

Quality Measures Web site provides these statistics 

each year. In addition, the coverage rates are also 

available for males and females separately. 

Reference period. Time interval to which survey 

responses refer. For example, many ACS questions 

refer to the day of the interview; others refer to “the 

past 12 months” or “last week.” 

Residence rules. The series of rules that defi ne who 

(if anyone) is considered to be a resident of a sample 

address for purposes of the survey or census. 

Sampling error. Errors that occur because only 

part of the population is directly contacted. With any 

sample, diff erences are likely to exist between the 

characteristics of the sampled population and the 

larger group from which the sample was chosen.

Sampling variability. Variation that occurs by chance 

because a sample is surveyed rather than the entire 

population. 

Selected population profi les. An ACS data product 

that provides certain characteristics for a specifi c race 

or ethnic group (for example, Alaska Natives) or other 

population subgroup (for example, people aged 60 

years and over). This data product is produced directly 

from the sample microdata (that is, not a derived 

product). 

Single-year estimates. Estimates based on the set 

of ACS interviews conducted from January through 

December of a given calendar year. These estimates 

are published each year for geographic areas with a 

population of 65,000 or more. 

Standard error. The standard error is a measure of 

the deviation of a sample estimate from the average of 

all possible samples. 

Statistical signifi cance. The determination of 

whether the diff erence between two estimates is not 

likely to be from random chance (sampling error) alone. 

This determination is based on both the estimates 

themselves and their standard errors. For ACS data, 

two estimates are “signifi cantly diff erent at the 90 

percent level” if their diff erence is large enough to infer 

that there was a less than 10 percent chance that the 

diff erence came entirely from random variation. 

Subject tables. Data products organized by subject 

area that present an overview of the information that 

analysts most often receive requests for from data 

users. 

Summary fi les. Consist of detailed tables of Census 

2000 social, economic, and housing characteristics 

compiled from a sample of approximately 19 million 

housing units (about 1 in 6 households) that received 

the Census 2000 long-form questionnaire.

Thematic maps. Display geographic variation in map 

format from the geographic ranking tables.

Three-year estimates. Estimates based on 3 years 

of ACS data. These estimates are meant to refl ect the 

characteristics of a geographic area over the entire 

3-year period. These estimates will be published for 

geographic areas with a population of 20,000 or more.

Appendix A-1

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

The ACS provides information for many diff erent geographic areas. American Indian and Alaska Native areas 

for which there are currently ACS data (1-year and 

3-year estimates) are listed in Table 5 of the handbook. 

A detailed description of these areas, and others for 

which ACS data will be available in the future, is provided below. 

ACS estimates refl ect geographic area boundaries for 

legal entities (such as American Indian Reservations) as 

of January 1 of the year of data collection, or the last 

year of data collection in the case of a multiyear estimate. For statistical areas, such as tribal tracts, Alaska 

Native Villages Statistical Areas, or Oklahoma Tribal 

Statistical Areas, ACS estimates refl ect the most current 

defi nitions of statistical areas available at the time ACS 

data products are ready for release. 

Statistical areas are defi ned anew for each decennial 

census. Participant statistical areas—census block 

groups, census tracts, census county divisions, and 

Census Designated Places—are delineated by local 

planners through a Participant Statistical Areas 

Program. A comparable program for tribal governments, the Tribal Statistical Areas Program provides 

for the delineation of tribal statistical areas, such as 

tribal census tracts, by the Census Bureau in conjunction with tribes. As 2010 Census statistical areas and 

tribal statistical areas are delineated, approved, and 

validated, they will be refl ected in ACS data products. 

This will take place on a fl ow basis; some areas will be 

refl ected in ACS data products earlier than other areas. 

For example, 2010 Census tribal block groups, tribal 

tracts, and Census Designated Places defi ned by tribal 

governments will be refl ected in the 2010 1-year ACS 

estimates, 2008–2010 3-year ACS estimates, and the 

2006–2010 5-year ACS estimates, all of which will be 

released in 2011. For the most current information on 

the programs for these areas, including links for the 

Federal Register notices that describe the 2010 Census 

criteria and guidelines for recognizing and delineating 

these areas, see <http://www.census.gov/geo/www

/reference.html> and <http://www.census.gov/geo

/www/tsap2010/tsap2010.html>. `

American Indian and Alaska Native Areas

American Indian Reservations (AIRs) are governmental entities for which the Census Bureau provides 

ACS data. Federal American Indian Reservations 

(federal AIRs) are areas that have been set aside by 

the United States for the use of tribes, the exterior 

boundaries of which are defi ned in fi nal tribal treaties, 

agreements, executive orders, federal statutes, secretarial orders, or judicial determinations. The Census 

Bureau recognizes federal reservations as territory 

over which American Indian tribes have primary governmental authority. Federal reservations can be called 

colonies, communities, pueblos, rancherias, ranches, 

reservations, reserves, villages, Indian communities, 

and Indian villages. ACS data are also provided for 

State American Indian Reservations (SAIRs). The names 

of these reservations are followed by “State” in ACS 

data presentations. ACS data for entire federal AIRs 

and SAIRs are presented. Federal AIRs may cross state 

boundaries; federal AIRs and SAIRs may cross county, 

county, subdivision, and place boundaries; only the 

portions of the reservations in a given state are shown 

in the data products for that state. Lands that are 

administered jointly or claimed by two tribes, whether 

federally or state recognized, are called “joint use 

areas” and are treated as if they were separate 

American Indian reservations for data presentation 

purposes. 

American Indian Off -Reservation Trust Lands 

(ORTLs) are areas for which the United States holds 

title in trust for the benefi t of a tribe or individual 

Indian. Trust lands may be located on or off of a reservation. The Census Bureau recognizes and tabulates 

data for off -reservation trust lands, which are always 

associated with a specifi c federally recognized reservation and/or tribal government. Off -reservation trust 

lands associated with tribes that do not have a reservation appear in ACS data tabulations by tribal name, 

interspersed alphabetically among reservation names.

Oklahoma Tribal Statistical Areas (OTSAs) are 

statistical entities identifi ed and delineated by the 

Census Bureau in consultation with federally recognized American Indian tribes in Oklahoma that do not 

currently have a reservation, but once had a reservation in that state. OTSAs primarily represent the former 

reservation boundaries and are not required to conform 

to any other geographic entity for which the Census 

Bureau tabulates data. Lands that are administered 

jointly or claimed by two OTSAs are called “joint use 

areas” and are treated as if they were separate OTSAs 

for data presentation purposes.

Appendix 1. 

The Geography of American Indian and Alaska 

Native Areas
A-2 Appendix

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

off -reservation trust land such that statistics for these 

populations were adversely aff ected. To address this 

situation, and provide a more eff ective program for 

identifying small-area geography on reservations, the 

Census Bureau provides tribal offi cials for federal reservations and off -reservation trust lands the opportunity to defi ne tribal tracts and block groups for federal 

reservations and off -reservation trust lands. Tribal 

tracts and tribal block groups are conceptually similar 

to census tracts and block groups defi ned within the 

standard state-county-tract-block group geographic 

hierarchy used for tabulating and publishing statistical data. Also, just as in the case with standard census 

tracts and block groups, the Census Bureau emphasizes in its guidelines for defi ning tribal tracts and 

block groups the need for consistent boundaries to 

enhance the comparisons of ACS and other data across 

time.

Census Designated Places (CDPs) represent locally 

known, unincorporated communities that contain a 

mix of residential, commercial, cultural, and/or retail 

uses similar to that of an incorporated place of similar 

size in a similar geographic setting. CDP boundaries 

are updated and revised periodically to refl ect changes 

to the geographic extent of a place, for example, the 

annexation of part of a CDP by an adjacent incorporated place, such as a city. In ACS data products, CDPs 

on federal reservations are not included in separate 

lists of entities that are American Indian. Instead, these 

entities appear interspersed alphabetically among lists 

of places by state. 

Alaska Native Village Statistical Areas (ANVSAs) 

represent the residents, permanent and/or seasonal, 

for Alaska Native members of the defi ning Alaska 

Native Village (ANV). ANVSAs are located within the 

ANV’s historic/traditional region and are designed to 

represent the most densely populated portion of each 

ANV where Alaska Natives represent a majority of the 

population during at least one season of the year.

Alaska Native Regional Corporations (ANRCs)

are corporate entities established to conduct both business (for profi t) and nonprofi t aff airs of Alaska Natives 

pursuant to the Alaska Native Claims Settlement Act 

of 1972 (Public Law 92-203). Twelve ANRCs are geographic entities that cover most of the state of Alaska. 

The Annette Island Reserve—an American Indian reservation—is excluded from any ANRC; a thirteenth ANRC 

represents Alaska Natives who do not live in Alaska 

and do not identify with any of the 12 corporations. 

The Census Bureau does not provide data for this ANRC 

because it has no geographic extent. The boundaries 

of ANRCs have been legally established; the Census 

Bureau updates those boundaries with assistance from 

the 12 nonprofi t ANRCs. In AFF, ANRCs are listed separately from American Indian and Alaska Native Areas.

American Indian Tribal Subdivisions are legal subdivisions of federally recognized American Indian reservations, off -reservation trust lands, or OTSAs. These 

entities are internal units of self-government or administration that serve social, cultural, and/or economic 

purposes for American Indians living on a reservation, 

off -reservation trust land, or OTSA.

Tribal Designated Statistical Areas (TDSAs)

are statistical entities identifi ed and delineated for the 

Census Bureau by federally recognized American Indian 

tribes that do not currently have a federally recognized 

land base (that is, a reservation or off -reservation trust 

land). A TDSA generally encompasses a compact and 

contiguous area that contains a concentration of people who identify with a federally recognized American 

Indian tribe and in which there is structured or organized tribal activity. A TDSA may be located in more 

than one state, and it may not include area within an 

American Indian reservation, off -reservation trust land, 

Alaska Native Village Statistical Area, state designated 

American Indian statistical area, or OTSA. The intent of 

the TDSA program is to collect and tabulate data analogous to the data provided to tribes with a reservation 

and/or off -reservation trust land.

State Designated Tribal Statistical Areas (SDTSAs)

are designed to provide recognized tribes without 

a reservation and/or off -reservation trust land with 

meaningful statistical data for a geographic area relevant to their current data needs and present-day 

location. SDTSAs are delineated by a state liaison 

identifi ed by the governor’s offi ce in each state. Like 

the TDSA, the SDTSA generally encompasses a compact and contiguous area that contains a concentration 

of people who identify with a state-recognized Indian 

tribe and in which there is structured or organized 

tribal activity. Also, like the TDSA, the SDTSA may not 

include area within an American Indian reservation, 

off -reservation trust land, Alaska Native Village 

Statistical Area, TDSA, or OTSA. However, unlike the 

TDSA, a SDTSA may not be located in more than one 

state unless the tribe for which it is associated is recognized by these states. The intent of the SDTSA program 

is to collect and tabulate data analogous to the data 

provided to tribes with a reservation and/or off -reservation trust land.

Tribal Tracts and Tribal Block Groups are defi ned 

by the Census Bureau in cooperation with tribal offi -

cials to provide meaningful and relevant data for small 

geographic areas within the boundaries of federally 

recognized reservations and off -reservation trust lands. 

In the past, census tracts and block groups defi ned 

by state and county offi cials have sometimes had 

the eff ect of separating American Indian populations 

located within a single reservation and/or 
Appendix A-3

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

2005–2007, the estimates refl ect the boundary updates 

as of January 1, 2007. In the future, the Census Bureau 

plans to provide documentation indicating the geographic areas aff ected by boundary changes during a 

data collection period. 

Figure 1 depicts a hypothetical American Indian area 

(we’ll call this area a reservation for the purposes of 

this example). The area most lightly shaded depicts the 

boundaries of this reservation in 2004. Other shaded 

areas were added by boundary changes that took place 

in 2005 and 2006. The January 1, 2007, boundary is 

used to tabulate data for this reservation. Sample data 

collected from the entire shaded area are refl ected in 

the 3-year estimates that were released for this reservation in 2008. 

Boundaries for Geographic Entities

ACS data products refl ect the Census Bureau’s latest 

information on boundaries (for governmental entities, 

such as American Indian Reservations), and criteria and 

guidelines (for statistical areas). Information on boundaries for governmental entities is updated through the 

Boundary and Annexation Survey (BAS). As previously 

stated, boundary updates and corrections are collected 

and processed through the BAS and the information 

available as of January 1 of the last year of data collection is applied to data products. For example, for 

1-year estimates released in 2008 that represent data 

collected in 2007, the estimates refl ect the boundary 

updates as of January 1, 2007. For 3-year estimates 

released in 2008 that refl ect data collected in 

County C

State A

County B

Legend

State Boundary

County Boundary

January 1, 2007 Boundary

American Indian Area - January 2005

2005 Annexations

2006 Annexations

0 20 40 60 80 100 River

Miles

±

Boundary Changes - American Indian Area (2005 - 2006)

County A

State B

County A

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 1. Eff ect of Boundary Changes for a Hypothetical American Indian Area on 

 3-Year Estimates
A-4 Appendix

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Appendix 2. 

Conducting a Test of Statistical Signifi cance

Figure 1 presents a portion of a selected population 

profi le for Oregon showing data for educational attainment for the total population and the population group, 

“American Indian Alone or in Any Combination.” The 

data show the highest level of educational attainment 

for each group. Suppose you are conducting research 

designed to inform education policy of the American 

Indian population for the state of Oregon. You want to 

compare characteristics for the American Indian alone 

or in any combination population with the characteristics of the total population and want to focus on data 

for the percent of the population that has completed 

high school or completed a high school equivalency 

program. Note that the estimate for the total population is 26.9 percent and the estimate for the American 

Indian alone or in any combination population is 

26.0 percent. Can you draw the conclusion that the 

percent of the population that has completed high 

school or the equivalent is lower for the “American 

Indian alone or in any combination” population? You 

might be inclined to do so, but a better approach 

would be to perform a test of statistical signifi cance 

for these estimates. The next section shows you how 

to proceed.

Comparing Two Estimates in a Selected 

Population Profi le

A set of technical appendixes included with A Compass 

for Understanding and Using American Community 

Survey Data: What General Data Users Need to Know

is designed to provide data users with interest in 

technical details with the information they need. For 

example, Appendixes 3 and 4 provide information on 

sampling error and detailed instructions on how to 

work with margins of error. One of the most important sets of instructions relates to tests of statistical 

signifi cance. Tests of statistical signifi cance should 

be performed to compare two estimates, for example 

for diff erent populations, geographic areas, or time 

periods. Tests of statistical signifi cance will help you 

determine whether two estimates that might appear to 

be diff erent are, in fact, statistically diff erent. By conducting such tests, you can strengthen your analysis of 

data and report diff erences in estimates that are true 

diff erences and worthy of note.

Here’s how you should conduct such a test to determine if the diff erence between two estimates for 

diff erent populations is statistically signifi cant. 

Source: U.S. Census Bureau, American FactFinder, accessed at <http://factfi nder.census.gov>.

 Figure 1. Selected Population Profi le, Oregon: Total Population and American 

 Indian Alone or in any Combination, 2005–2007 ACS 3-year Estimates
Appendix A-5

U.S. Census Bureau, A Compass for Understanding and Using American Community Survey Data

Conducting a Test of Statistical Signifi cance 

1. Calculate the standard error, , associated with 

each of the two estimates:

 Where is the published margin of error 

for the ACS estimate.

 The estimate for the total population is 26.9 percent. The standard error of this estimate is

 The estimate for the American Indian alone or in 

any combination population is 26.0 percent. The 

standard error of this estimate is

2. Test whether the diff erence between the two estimates is signifi cant at the 90-percent confi dence 

interval using the formula:

 

 Where is the estimate for the total population,

 is the estimate for the American Indian alone 

or in any combination population, is the standard error for the total population, and is the 

standard error for the American Indian alone or in 

any combination population. 

 If the diff erence 

 between the two estimates is statistically signifi -

cant at the 90-percent confi dence level.

3. Perform the required calculations.

Because 0.77 is less than 1.65, you cannot conclude 

that the two estimates are statistically diff erent.1 The 

percentage of the population completing high school 

or a high school equivalency program are not statistically diff erent for the two population groups (the total 

population and the population representing American 

Indian alone or in any combination).

This information could be helpful in demonstrating that 

both populations have relatively comparable estimates 

regarding the percentage of the population for whom 

high school or a high school equivalency program is 

the highest level of educational attainment. The fi nding 

that these estimates are not statistically diff erent for 

the two populations might be important in an assessment of programs to improve educational achievement 

among the American Indian population. 

SE = 

1.645

MOEACS

SE =

= 1.645

0.3

 = 0.18

= 1.645

1.9

 = 1.16

ZCL

SE SE

X X

!





2

2

2

1

2

^

1

^

2 2 (0.18) (1.16)

26.9 26.0



 >1.645,

2 2 (0.18) (1.16)

26.9 26.0



 = 0 .77

X 1

X 2

SE1

SE2

MOEACS

SE1

SE2

1 In this example we compared an estimate of a portion of the total 

population (“American Indian alone or in any combination”) with an 

estimate of the total population. Because the “American Indian alone or 

in any combination” population is included in the total population, the 

two estimates are considered to be correlated. When such comparisons 

are made, usually an adjustment is needed to account for this correlation. However, in this example, the correlation is expected to be small 

because the “American Indian alone or in any combination” population 

is such a small fraction of the total population. Therefore the simple 

test for statistical signifi cance that we used is reasonable.

^

^

^

^