# Presentation: 934235

## An Overview of the American Community Survey

- An Overview of the American Community Survey

**Notes:**
Have you ever thought about how, or why, new roads, schools, after-school programs, or hospitals are placed in communities? What makes communities attractive to new businesses or tourists? Why there is no ATM or video store on a street corner?

The answers often lie in the numbers: numbers that reflect what our communities look like, how our communities have changed, and how those changes impact our daily lives. Most importantly, the numbers reflect how our communities are meeting the needs created by these changes. Traditionally, these numbers have been collected during the census every 10 years. Those numbers play a critical role for states and local communities in determining their share of federal money for schools, roads, senior citizen centers, and other services.

In today’s world, our communities can change very quickly. Between decennial censuses, local governments, organizations and businesses need timely data to assess and plan for local needs.  Costly mistakes can result when planners do not have current data on which to base their decisions.  That is one of the reasons why the U.S. Census Bureau has moved to a whole new way of gathering data to help answer those questions.  Rather than taking a snapshot of a community once every ten years, the American Community Survey provides a dynamic and much timelier moving picture of the nation, every year. 

## Overview

- What is the American Community Survey?
- Content
- Survey Methodology
- Data Products
- How is it different from Census 2000?

**Notes:**
This presentation will give you an overview of the American Community Survey. We will answer the question “What is the American Community Survey?” and then move on to discuss the content, methodology, and data products. We will wrap up with a brief summary of how the American Community Survey is different from Census 2000.

## What is the American Community Survey?

- What is the American Community Survey?

**Notes:**
The American Community Survey, sometimes referred to as the ACS, is a nationwide survey that collects essentially the same information on people and housing that was collected on the long-form questionnaire used in Census 2000.  The American Community Survey is a continuous survey, in which each month a sample of housing unit addresses receives a questionnaire. About three million addresses are surveyed each year.

The American Community Survey is a critical element in the Census Bureau's new approach to future censuses.  

## Decennial Census 

- Decennial Census

- In Census 2000, the census used 2 forms
- “short” form – asked for basic demographic and housing information, such as age, sex, race, how many people lived in the housing unit, and if the  housing unit was owned or rented by the resident
- “long” form – collected the same information as the short form but also collected more in-depth information such as income, education, and language spoken at home
- Only a small portion of the population, called asample, received the long form.

**Notes:**
Two forms were used during Census 2000. The “short form” asked several questions on the most basic demographic and housing topics. These questions asked about age, sex, race, Hispanic origin, the number of people living in the housing unit, and if the housing unit was owned or rented by the resident.

The “long form” collected the same information as the “short form,” but it also asked questions on additional topics. Thirty-two questions were asked of each resident of the housing unit on such topics as marital status, education, language spoken at home, employment, occupation, and others. Twenty-one questions were asked about the housing unit itself, so only one resident of that housing unit was asked to provide information on such topics as plumbing and kitchen facilities,  type and cost of utilities, value of the property, and others. 

Only a sample of the total U.S. population received the long form. The data from the long form are called “sample data.”  The basic data collected on both the short and the long forms are called “100 percent data” since these questions were asked for 100 percent of the U.S. population.

## 2010 Census and American Community Survey

- 2010 Census and American Community Survey

- 2010 Census will focus on counting the U.S. population
- The sample data are now collected in the ACS
- Puerto Rico is the _only_ U.S. territory where the ACS is conducted
- 2010 Census will have a long form for U.S. territories such as Guam and U.S. Virgin Islands
- Same “short form” questions on the ACS

**Notes:**
The upcoming 2010 Census will include only one form sent to the entire U.S. population. That form will ask only questions similar to those contained in previous census short forms. The 2010 Census will provide a basic count of the U.S. population, collecting only the most basic demographic and housing information. Detailed demographic, social, economic, and housing data will no longer be collected as part of the decennial census. 

The data that were collected from the long form sample are now produced from the American Community Survey. 

The American Community Survey collects data from the 50 states, the District of Columbia, and Puerto Rico, where it is called the Puerto Rico Community Survey. The American Community Survey does not collect data from the other U.S. territories, such as Guam and the U.S. Virgin Islands. The 2010 decennial census will continue to collect long form type data for these areas. 

The questions that are asked on the 2010 Census are also asked on the American Community Survey questionnaire. 

## American Community SurveyContent

- American Community SurveyContent

**Notes:**
The content collected by the American Community Survey can be grouped into four main types of characteristics – social, economic, housing, and demographic. Let’s take a closer look at the type of information each of these categories contain.

## American Community Survey Social Characteristics

- American Community Survey Social Characteristics

-   Education
-   Marital Status
-   Fertility
-   Grandparent    Caregivers
-   Veterans
-   Disability Status

-   Place of Birth
-   Citizenship
-   Year of Entry
-   Language Spoken   at Home
-   Ancestry / Tribal
-    Affiliation

**Notes:**
Social characteristics include topics such as education, marital status, fertility, grandparent caregivers, veterans, disability status, place of birth, citizenship status, year of entry, language spoken at home, ancestry and tribal affiliation.

## American Community Survey Economic Characteristics

- American Community Survey Economic Characteristics

-   Income
-   Benefits
-   Employment Status
-   Occupation
-   Industry
-   Commuting to Work
-   Place of Work

**Notes:**
Economic characteristics include such topics as income, benefits, employment status, occupation, industry, commuting to work, and place of work. Data on the economic characteristics of the population are collected to assess the well-being of individuals and households.

## American Community Survey Housing Characteristics

- American Community Survey Housing Characteristics

-   Tenure
-   Occupancy & Structure
-   Housing Value
-   Taxes & Insurance
-   Utilities
-   Mortgage/Monthly Rent

**Notes:**
Housing characteristics include topics such as tenure, occupancy and structure, housing value, taxes and insurance, utilities, and mortgage or monthly rent. This housing data gives us a measure of the housing stock of the country.

## American Community Survey Demographic Characteristics

- American Community Survey Demographic Characteristics

-   Sex
-   Age
-   Race
-   Hispanic Origin

**Notes:**
The American Community Survey also collects the basic demographic characteristics such as sex, age, race and Hispanic origin. This is the same information that will be collected by Census 2010.

## American Community Survey2008 Content Changes

- American Community Survey2008 Content Changes

- Three new questions
- Health Insurance Coverage
- Veteran’s Service-connected Disability
- Marital History
- Deletion of one question
- Time and main reason for staying at the address
- Changes in some wording and format

**Notes:**
Several changes were made to the American Community Survey questionnaire at the beginning of 2008. Three new questions were added and one question was deleted. The three new questions are on health insurance coverage, veteran’s service-connected disability, and marital history.  These new data will begin to be available during the data release in 2009. The deleted question measured the time and main reason for staying at the sampled address. These data were used for internal research purposes and the data were not published in the data products. Changes were also made to some of the demographic questions so that they are consistent with the questions that will be on the 2010 Census questionnaire.

## American Community Survey Methodology

- American Community Survey Methodology

- Sample includes about 3 million addresses each year
- Three modes of data collection
- mail
- phone
- personal visit
- Data are collected continuously throughout the year

**Notes:**
About 3 million addresses are selected for the American Community Survey sample every year.

The American Community Survey data collection operation uses three modes that take place over a three-month period: mail, telephone, and personal visit. For most housing units the first phase of data collection includes a questionnaire mailed to the sample address for the household to complete and return by mail.  If no response by mail is received, the Census Bureau follows up with computer assisted telephone interviewing, or CATI, if a telephone number is available for the address.  If the Census Bureau is unable to reach an occupant of the unit using CATI, or if the household refuses to participate, the address may be selected for computer assisted personal interviewing, or CAPI.  At any point in this process, receipt of a completed questionnaire from the sampled address results in the address being removed from the data collection workload. 

Data for the American Community Survey are collected continuously throughout the year.  Interviews conducted between January 1st and December 31st of a given year are aggregated to produce annual estimates for calendar years. For example, interviews conducted between January 1st and December 31st of 2009 are aggregated to produce estimates for 2009.

## American Community SurveyTarget Population

- American Community SurveyTarget Population

- Resident population of the United States and Puerto Rico
- Living in housing units and group quarters
- Current residents at the selected address
- “Two month” rule

**Notes:**
Interview and residence rules define the target population for a survey.  These rules therefore identify the units and the people eligible for inclusion in the survey.  The sampling frame reflects this choice of universe, as do the instructions on the forms and in the procedures used by survey interviewers during follow-up. The American Community Survey collects data from all persons without regard to their legal status or citizenship. In 2005 the target population was limited to the housing unit population of the US and Puerto Rico. For the first time in 2006, and for every year thereafter, the American Community Survey has included the resident population living in BOTH housing units and group quarters. 

The American Community Survey residence rules were established to collect data from people who are currently living at the selected address. For inclusion in the survey, these rules require that, at the time the questionnaire is completed, the respondent is living or staying at the housing unit address for more than two months.  

## American Community SurveyGroup Quarters 

- American Community SurveyGroup Quarters

- Place where people live or stay that is normally owned or managed by an entity or organization providing housing or services for the residents.
- 2 categories of group quarters:
- Institutional
- Non-institutional

**Notes:**
Group quarters are places where people live or stay that are 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, and residency is commonly restricted to those receiving these services. 

The group quarters population is divided into two categories, the Institutional group quarters population and the Non-institutional group quarters population.

The Institutional group quarters population includes residents under formally authorized supervised care. Examples of these facilities include skilled nursing facilities, adult correctional facilities, and psychiatric hospitals.

The Non-institutional group quarters population includes residents of college/university housing, military barracks, and group homes.

## American Community Survey Period Estimates

- American Community Survey Period Estimates

- ACS estimates are period estimates, describing the average characteristics over a specified period
- Contrast with point-in-time estimates that describe the characteristics of an area on a specific date
- 1-year, 3-year, and 5-year estimates will be released for geographic areas that meet specific population thresholds

**Notes:**
American Community Survey period estimates describe the average characteristics of the population or housing over a specified period of time. In the case of American Community Survey one-year estimates, the period is the calendar year. For example, the 2007 American Community Survey data describe the population and characteristics of an area from January 1, 2007 through December 31, 2007, not for any specific day within the year. 

The American Community Survey collects survey information continuously nearly every day of the year and then aggregates the results over a specific period of time – one year, three years, or five years.  The data collection is spread evenly across the entire period represented so as not to over-represent any particular month or year within the period.  

## American Community Survey Data Products Release Schedule

- American Community Survey Data Products Release Schedule

| Data Product | Population Size |  |  |  | Data rele | ased in:  |   |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | of Area | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 |
| 
1-Year Estimates | 65,000+ | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
| for Data Collected in: |  |  |  |  |  |  |  |  |  |
| 
3-Year Estimates | 20,000+ |  |  | 2005-2007 | 2006-2008 | 2007-2009 | 2008-2010 | 2009-2011 | 2010-2012 |
| for Data Collected in: |  |  |  |  |  |  |  |  |  |
| 
5-Year Estimates | All Areas* |  |  |  |  | 2005-2009 | 2006-2010 | 2007-2011 | 2008-2012 |
| for Data Collected in: |  |  |  |  |  |  |  |  |  |

- * Five-year estimates will be available for areas as small as census tracts and block groups.
- Source: US Census Bureau

**Notes:**
This slide shows the data products release schedule for 2006 through 2013. 

All American Community Survey data are published based on population thresholds. One-year estimates from the American Community Survey are published for geographic areas with a population of 65,000 or more, including counties or county equivalents, all Congressional Districts, metropolitan and micropolitan statistical areas, all 50 states, the District of Columbia, and Puerto Rico.  2007 American Community Survey one-year estimates were released in September 2008.

Data will be available for areas with estimated populations of 20,000 or greater in December 2008. These three-year estimates will be produced with data collected from the 2005, 2006 and 2007 American Community Surveys. 

The Census Bureau plans to release data for all areas, including those with estimated populations of less than 20,000, by the end of 2010. For small areas with populations less than 20,000, it will take five years to accumulate a large enough sample to provide estimates with accuracy similar to the decennial census long form. These five-year estimates will be produced from the data collected from the 2005, 2006, 2007, 2008, and 2009 American Community Surveys. 

Once published for the first time, all American Community Survey data products are refreshed annually.

## American Community SurveyData Products

- American Community SurveyData Products

- Profiles
- Data Profiles
- Narrative Profiles
- Comparison Profiles
- Selected Population Profiles
- Tables
- Detailed Tables
- Subject Tables
- Ranking Tables
- Geographic Comparison Tables
- Thematic Maps
- Public Use Microdata Sample (PUMS) Files

**Notes:**
The American Community Survey data products are similar to those produced from the decennial census long form.  Like the decennial sample data products, the American Community Survey products show the characteristics of the country’s population and housing.  These products include four broad types of products – profiles, tables, thematic maps, and Public Use Microdata Sample, or PUMS, files. There are multiple types of profiles and tables – data profiles, narrative profiles, comparison profiles, selected population profiles, detailed tables, subject tables, ranking tables, and geographic comparison tables.

All of the data products are available on the Census Bureau’s American FactFinder.  The data products are explored in depth in the presentation titled “Data Products from the American Community Survey.”

## American Community Survey Learning More

- American Community Survey Learning More

- ACS Main Page
- 2007 Data Product Details
- Subject Definitions
- Guidance on Comparing 2007 Data to Other Sources
- Design and Methodology Report
*The ACS Compass Products*

**Notes:**
The American Community Survey Web site has a lot of information about the program, its data products, and evaluation of the data. The next several slides will present some valuable resources for learning more about the American Community Survey. We will look at the ACS Main page, the 2007 Data Product Details, Subject Definitions, Guidance on Comparing 2007 Data to Other Sources, the ACS Design and Methodology Report, and The ACS Compass Products.

The upcoming slides show static images of the American Community Survey Web site taken in late-September 2008. As the Web site is continually updated, these images may differ slightly from what is currently on the active Web site. At the bottom of each of the upcoming slides are the Internet addresses for the Web page that the slide is referencing.

## American Community SurveyACS Main Page

- American Community SurveyACS Main Page

*http://www.census.gov/acs/www*

## American Community Survey 2007 Data Release

- American Community Survey 2007 Data Release

*http://www.census.gov/acs/www/Products/*

**Notes:**
The 2007 ACS Data Release page includes links to four ways to access American Community Survey data. They are the American FactFinder, the File Transfer Protocol or FTP site, the Public Use Microdata Sample or PUMS files, and Request a Custom tabulation. It also contains data user tools and tips as well as important documentation. This page is where you can access much of the information you may need when using American Community Survey data. In the image on this slide, arrows highlight hyperlinks to 2007 Data Product Details and Comparing ACS Data, both located under the Data User Tools and Tips column. Under the Documentation column, arrows highlight hyperlinks to Subject Definitions, Errata, User Notes, and the ACS Design and Methodology report.

We will now briefly explore each of these resources.

## American Community Survey 2007 Data Product Details

- American Community Survey 2007 Data Product Details

*http://www.census.gov/acs/www/Products/users_guide/*

**Notes:**
The 2007 Data Product Details contains table shells and their ID numbers, maps, geographic areas, and more. 

At the top left of the page, you can use the drop down menu to select the state you’re interested in and it will produce the list of geographic areas that are published for that state. There will be a similar tool for the three-year estimates that will be released in December 2008.

The box in the middle of the page allows you to look at table shells by topic. These table shells do not contain any data, however they are a useful mechanism for seeing the data that are offered and the format of those data before going to American FactFinder to begin your data retrieval.

At the bottom of the page you’ll find some downloadable files that contain detailed documentation on the data products. One of these files allows users to see if the 2007 American Community Survey produced a table that is comparable to a table produced from the Census 2000 Summary File 3. Another file lists all of the tables that are new, have been deleted, or have been modified since the release of the previous year’s data. Also on this page is a document that provides instructions for applying statistical testing to American Community Survey data, so that you can test to see whether changes in the data are statistically valid. Each of these files will open in a new window and can be saved on your computer. 

## American Community Survey 2007 Data Product Details

- American Community Survey 2007 Data Product Details

**Notes:**
The image on this slide shows the table crosswalk that is found by clicking on the link titled “Census 2000 Summary File 3 detailed tables with comparable ACS tables.” The crosswalk offers information about the table’s title, id number and the subject area  for both the Census 2000 Summary File 3 and the 2007 American Community Survey.  It also contains information on how the 2007 American Community Survey and Census 2000 Summary File 3 tables correspond to one another. This is available as a downloadable Excel file from the Data Product Details page. 

## American Community Survey Comparison Guidance

- American Community Survey Comparison Guidance

- Comparing 2007 ACS to 2006 ACS
- Census Bureau supports comparisons made between 2006 and 2007 ACS data
- Comparing 2007 ACS to Census 2000
- Differences between the 2007 ACS and Census 2000 include residence rules, universes, and reference periods.

**Notes:**
The Census Bureau provides guidance to users that want to compare 2007 American Community Survey data with data from other sources. You will also find a link on this web page to guidance on comparing 2006 ACS data to other sources. Guidance is needed before drawing conclusions because in some instances comparisons could be misleading due to differences in questions or methods. 

The Census Bureau supports comparisons made between 2006 and 2007 ACS data.  

When comparing 2007 American Community Survey data to Census 2000 data, the user should keep in mind the differences that exist between the 2007 ACS and Census 2000. As noted earlier, these include differences in residence rules, universes, and reference periods. For example, the 2007 ACS uses a "two-month" residence rule - defined as anyone living for more than two months in the sample unit when the unit is interviewed whereas Census 2000 used a "usual residence" rule - defined as the place where a person lives or stays most of the time.

We encourage you to review the guidance on our website which provides useful information for every variable.

## American Community Survey Comparing Data

- American Community Survey Comparing Data

*http://www.census.gov/acs/www/UseData/compACS.htm*

**Notes:**
The image on this slide shows the page on the ACS website that provides general guidance and item-specific guidance. Examples that demonstrate how the user would navigate through the Web site to get guidance on a specific item of interest are also provided. For all comparisons of differing time periods, users should take into consideration that geographic boundaries for the area of interest may have changed.

This “screenshot” shows the beginning of the item-specific guidance. The item is listed in the left column, guidance on comparing the 2007 ACS to Census 2000 is in the middle column, and guidance on comparing the 2007 ACS to the 2006 ACS is in the right column. Each cell in the middle and right columns offer a “more info” link that will offer explanations of the Census Bureau’s recommendations. In the middle column comparing the 2007 American Community Survey to Census 2000, there is also a “table crosswalk” link that will take you to the same crosswalk that we just discussed. 

## American Community Survey User Notes

- American Community Survey User Notes

*http://www.census.gov/acs/www/UseData/usernotes.htm*

**Notes:**
The user notes section provides important information about the data by specific year.  For example, the first note listed on the screen references the “Modification Made in 2007 ACS Weighting Methodology for Orleans and St. Bernard Parishes in Louisiana.” It states the following:

“The review of the 2007 operational data discovered evidence that suggests a high incidence of misclassification of uninhabitable units as vacant units. The effect of misclassification was almost entirely removed through a modification in the weighting methodology for Orleans and St. Bernard Parishes. The effect of the weighting adjustment was to down-weight units that had the vacancy status of ‘Other Vacant.’ This modification resulted in more consistent and accurate ACS estimates of the number of vacant units and ‘persons per household’ in these two parishes. This modification was also made to the 2006 ACS weighting methodology.”

## American Community Survey Errata Notes

- American Community Survey Errata Notes

*http://www.census.gov/acs/www/UseData/Errata.htm*

**Notes:**
The Errata notes page will provide users with information on any updates made to the data due to detected errors. For example, the errata note 46, which is the first entry on the screen, references “Subject Table S2101 and Base Table B21002 for years prior to 2007, period of military service.” The errata note states the following:

“Due to an editing error, veteran's period of service (VPS) was being incorrectly assigned for some individuals. The majority of the errors misclassified some people who reported only serving during the Vietnam Era as having served in the category “’Gulf War and Vietnam Era.’ The remainder of the errors misclassified some people who reported only serving between the Vietnam Era and Gulf War as having served in the category ‘Gulf War.’ These errors have been resolved for the 2007 tabulations.“

## American Community Survey Subject Definitions

- American Community Survey Subject Definitions

*http://www.census.gov/acs/www/UseData/Def.htm*

**Notes:**
The Subject Definitions document is a glossary of all American Community Survey measures. In the 2007 version, definitions of the quality measures describing American Community Survey data have been added. Versions for the 2002 through 2007 American Community Surveys are available.

## American Community Survey Subject Definitions

- American Community Survey Subject Definitions

**Notes:**
The Subject Definitions document includes explanations of the measures. For example, the partial definition of the “Language Spoken at Home and Ability to Speak English” measure that is shown on this slide tells us that the questions are only asked of people aged 5 years and older. The full definition provides other important information about this measure.

## American Community Survey Design and Methodology Report

- American Community Survey Design and Methodology Report

- Important reference document covering  methods used in producing ACS data

- Available at *http://www.census.gov/acs/www/Downloads/tp67.pdf*

**Notes:**
The ACS Design and Methodology paper describes the basic design of the American Community Survey and details the full set of methods and procedures that are currently in place. An updated version of the paper is forthcoming.

This report can be accessed from the 2007 Data Release page.

## American Community Survey How to Use the Data

- American Community Survey How to Use the Data

*http://www.census.gov/acs/www/UseData.htm*

**Notes:**
The geography notes section provides a brief explanation of the Census Bureau’s geographic terms.  Geography notes are located on the “How to Use the Data” Web page.  The yellow toolbar that sits just below the American Community Survey banner is accessible from all pages on the American Community Survey Web site.  Click on “How to Use the Data,” which is the fourth tab from the right. The image on this slide shows the “How to Use the Data” page. The link to Geography Notes is located in the right hand column.  

## American Community Survey Geography Notes

- American Community Survey Geography Notes

*http://www.census.gov/acs/www/UseData/geo.htm*

**Notes:**
The geography notes provide an overview of the types of geographic areas that are presented in American Community Survey data products. At the bottom of the page are printable .pdfs for the current year and past years of the American Community Survey.   

## American Community Survey The ACS Compass Products

- American Community Survey *The ACS Compass Products*

- Set of educational handbooks aimed at specific audiences
- Presentation slides on important ACS topics
- E-learning tutorial

**Notes:**
In recognition of the need to provide guidance on new concepts and the challenges they bring to users of American Community Survey data, the U.S. Census Bureau is developing a series of educational materials called The ACS Compass Products.

The ACS Compass Products include user-specific handbooks, PowerPoint presentations, and an on-line tutorial.

The handbooks provide user-friendly information about the ACS and the multiyear estimates available in 2008. Each handbook targets a specific user group including first time ACS data users. 

The PowerPoint presentations, such as this, provide important information on various aspects of the American Community Survey. These presentations were developed for two main purposes: (1) for individual to use to learn more about the ACS and (2) to provide a wide audience with the tools needed to conduct training on the ACS.  Each presentation consists of approximately 35 slides and the accompanying speakers’ notes. The presentations have also been recorded as multimedia files so users can learn about the ACS without having to read the presentations or attend a training session. 

An on-line tutorial that enables users to understand and appropriately use ACS data is also planned for future release. 

## American Community SurveySimilarities with Census 2000

- American Community SurveySimilarities with Census 2000

- Same questions and many of the same basic statistics
- 5-year estimates will be produced for same broad set of geographic areas including census tracts and block groups

**Notes:**
Now that we have explored the American Community Survey program and products, let’s wrap up by answering the question “How is the American Community Survey different from Census 2000?”

As mentioned earlier, the American Community Survey asks many of the same questions and produces many of the same basic statistics as the sample data from Census 2000. 

American Community Survey data will be produced for geographies as large as the nation and as small as block groups. Five-year estimates will be produced for the same broad set of geographic areas that received sample data from Census 2000, including census tracts and block groups. 

## American Community SurveyKey Differences from Census 2000

- American Community SurveyKey Differences from Census 2000

- Beginning in 2010, data for small geographic areas will be produced every year versus once every 10 years
- Data for larger areas are available now and data for mid sized area will be available in December 2008
- Census 2000 data described the population and housing as of April 1, 2000 while ACS data describe a period of time and require data for 12 months, 36 months, or 60 months

**Notes:**
As opposed to the decennial census which produced data once every 10 years, the American Community Survey will provide a continuous stream of updated information for states and local areas. Updated data from the American Community Survey will be released every year. 

Updated data have been available since 2005 for areas with populations of 65,000 or more. Data in the form of three-year estimates will be available for areas with populations of 20,000 or more in December 2008.

American Community Survey estimates provide information about the characteristics of population and housing for areas over a specified period of time. American Community Survey single-year and multiyear estimates contrast with “point-in-time” estimates, such as those from the decennial census long form samples, which are designed to measure characteristics as of a certain date or narrow time period.  For example, Census 2000 was designed to measure the characteristics of population and housing in the United States based upon data collected around April 1, 2000, and thus its data reflect a narrower timeframe than American Community Survey data. 

## American Community SurveyKey Differences from Census 2000

- American Community SurveyKey Differences from Census 2000

- The goal of ACS is to produce data comparable to the Census 2000 long form data
- These estimates will cover the same small areas as Census 2000 but with smaller sample sizes
- Smaller sample sizes for 5-year ACS estimates results in reductions in the reliability of estimates

**Notes:**
In Census 2000 approximately 17 percent of the housing units received a long form. Statistics from this sample were produced for a broad set of geographic areas including the nation, all states, counties, census tracts, and block groups.

Five years of American Community Survey data are needed to produce estimates comparable to the estimates produced from the Census 2000 long form. A benefit that users will gain from the American Community Survey is the more timely issuance of the data and the greater frequency with which the data are released. Also, it produces information for small areas, including tracts and block groups, which will be updated every year instead of once every decade.

The sample sizes for the 5-year ACS estimates will be smaller than the sample sizes were for Census 2000. This will result in a reduction in the reliability of the estimate. 

## For more information

- Subscribe to “ACS Alert”
- http://www.census.gov/acs/www/Special/Alerts.htm
- Visit the ACS/PRCS website:
- http://www.census.gov/acs/www
- Contact by telephone:
- 1-800-923-8282
- Contact by email:
- acso.users.support@census.gov