DC/SLA Program on Census Data Tools 9/21/2010

by Eileen Boswell
On September 21 the Chapter held a program on using data from Census 2010 and the American Community Survey for research, with a presentation by Census Bureau Services Statistician Troy King. The main differences between the decennial census and the American Community Survey (ACS) are how often the data are collected and from how many people, as well as the level of detailed information resulting from each one.

Census data are collected once every ten years, and the primary purpose of the Census is a population count, to be used for Congressional reapportionment. Census data sets are released through the American FactFinder website. (See projected release dates for 2010 Census data here.) ACS is conducted annually, but not everyone in the country will have an opportunity to participate, unlike the decennial census. The main purpose of ACS is to provide up-to-date information about the social and economic characteristics of American communities. For example, results may be used to decide where new schools, hospitals, and emergency services are needed. There is always a one-year delay in the release of ACS data. (See projected release dates for 2010 ACS data here.)

The group discussed the relative value of using 1-year, 3-year, and 5-year data estimates from ACS. King walked us through a very helpful table (see below) that shows under which circumstances you would use each data set. For example, 1-year estimates are best used when currency is more important than precision, and when analyzing large populations.
Caption: Distinguishing features of ACS 1-year, 3-year, and 5-year estimates (See this information online here).

Among the other great resources we learned about were:

* kids' pages with games and age-appropriate information
* data users' handbooks
* thematic maps
* PowerPoint training presentations complete with speaker notes, and
* the Census Bureau Training and Education schedule, including a course called Understanding Federal Statistics.

One attendee, Michelle Polchow, had this reflection on the program: "The Census Bureau offers a great model of information literacy. Supporting complex electronic data with free training opportunities, offered in a variety of instructional formats, is a socially responsible solution."

Many thanks to Steve Mellin at Jenner & Block for hosting this program in a beautiful and comfortable venue!