1. ENT/LIS/GEO 530

2. The Constitution says…
Article 1, Section 2 of the United States Constitution:
“Representatives and direct taxes shall be
apportioned among the several states which may be
included within this union, according to their
respective numbers ... The actual Enumeration shall
be made within three years after the first meeting of
the Congress of the United States, and within every
subsequent term of ten years, in such manner as they
shall by law direct.”

3. Basics of Census 2000
Short Form
Survey of 100% of the
population
Questions about the
basic demographic
characteristics
age, race, number of
people in a housing
unit
Long Form
Sample of one in six
housing units
Basic demographic
questions
PLUS questions about
socioeconomic topics

education, income,
housing characteristics,
employment, and
disability status

4. Basics of Census 2010
Short Form
Continue
constitutionally
mandated short form
counting 100% of the
population
Long Form
Replaced by the
American Community
Survey (ACS)
Census count is focused
on coverage
American Community
Survey is focused on
content

5. Basics of the
American Community Survey
A nationwide, continuous monthly survey
Annual sample size = around 3 million addresses
Data products will be released annually
Profiles available every year for communities of
65,000 or more people
Profiles available in 3 to 5 year estimates for
communities with fewer than 65,000 people

6. Benefits of the ACS
Provides timely data between the decennial censuses
Examples in past decade when would matter?
Provides ability to monitor trends in local
communities between censuses
Examples of how useful?
Permanent, professional interviewers
Why matter?

7. But keep in mind …
Estimates
Sample is small and requires aggregation of data over
time for smaller locations
Point in time versus period data
Counting on April 1 of census year versus counting
continuously throughout year
Margins of error and confidence intervals
Figures are an estimate with a confidence interval of
90%

8. Availability for particular places
Burlington, NC has
49,038 (ACS 20062008)
Reidsville, NC
has 14,485
(Census 2000)
5-year estimate
(2005-2009)
available now
Two 3-year estimates
(05-07 & 06-08) and
one 5-year estimate.
Greensboro, NC has
242,817 (ACS 20062008)
Any 1-year, 3-year, 5year estimate could be
used.

9. Point in time versus period data
Census
American Community Survey
 Point in time data
 Period data
 Reference point is April 1
 Reference period is past 12
months

10. Differences in Questions
Census
American Community Survey
 31. INCOME IN 1999
 47. INCOME IN THE PAST 12
 a. Wages, salary,
commissions, bonuses, or tips
from all jobs - Report amount
before deductions for taxes,
bonds, dues, or other items.
 O Yes
Annual amount – Dollars
$[ ][ ][ ],[ ][ ][ ].00
 O No
MONTHS.
 a) Wages, salary, commissions,
bonuses, or tips from all jobs.
 Report amount before
deductions for taxes, bonds,
dues, or other items
 Yes -->
$____________________.00
(TOTAL AMOUNT for past 12
MONTHS)
 No

11. Margins of Error
Census data has margins of error built in; ACS data
publishes the MoE
Census Bureau data has a confidence interval of 90%
How would we interpret this?
Albany County 258, 649 +/-2,191
We are 90% confident that the true value is between
256,458 and 260,840. There is a 10% probability that
the estimate would be outside this range.

12. Putting it into practice
Question
Questions to ask
• I’m looking for recent
 Time?
information on number of
people by age and race
for census tracts in
Greensboro, NC.
 What is recent? 2000 or
2005-2009 data?
 Geography?
 Census tracts
 Topic of question?
 Age and race of people

13. American FactFinder (AFF)
Contains
American Community Survey
Census 2010 & 2000 data
Economic Census
Population estimates
And more!
http://factfinder2.census.gov/

14. References
 Herman, E. (2008). The American Community Survey: An introduction to the basics. Government
Information Quarterly 25, 504-519.
 Mather, M., Rivers, K. L., & Jacobsen, L.A. (2005). The American Community Survey. Population
Bulletin, 60(3), 3-20.
 North Carolina Office of State Budget & Management. (2008). NC SDC 2008 Annual Meeting
Materials. Retrieved January 27, 2009 from
http://www.osbm.state.nc.us/ncosbm/facts_and_figures/state_data_center/AnnualMeetings/
 North Carolina Office of State Budget & Management. (2008). North Carolina is counting on you!
Retrieved January 27, 2009 from
http://www.osbm.state.nc.us/ncosbm/facts_and_figures/census/nc2010/
 Taeuber, C. M. (2006). American Community Survey for Community Planning. Oxford: Trafford
Publishing.
 U.S. Bureau of the Census. (2008). A compass for understanding and using American Community
Survey Data What general data users need to know. Retrieved December 1, 2009 from
 http://www.census.gov/acs/www/Downloads/ACSGeneralHandbook.pdf