While certain parts of the dicennial Census have remained the same, a sociologist outlines some data collection changes between 2000 and 2010:

In 2000 the short form included only eight questions for the householder and six for every person living in the household. These were the same basic questions that would be asked in 2010 about sex, age, relationship to the householder, race and Hispanic status.

About one in six households received the “long form,” which included some 53 questions. In addition to the basic questions in every census form, this survey also contained questions on a whole panoply of characteristics, including housing, moving in the last five years, employment, detailed income sources, military service, disability status, ancestry, place of birth and education.

Until 2010, the long form and short form were distributed in tandem, but then the government split them. Beginning in 2005, the Census Bureau began to collect data for the American Community Survey, which is very similar to the old long form. That survey gets responses from about 2 million households and residents of group quarters (prison, dormitory, institution) every year, and tracks the same sort of data that was produced by the long form sample. The survey takes place all year and interviews, where necessary, are conducted by permanent staff — not the temporary workers who interview for decennial census.

The Census Bureau releases three sets of data each year from the community survey: the one-year, the three-year and the five-year files. The one-year file is released for areas of at least 65,000 in population, the three-year file for areas of at least 20,000 and the five-year file for all of the areas for which the long form was released (block-groups, tracts and higher). The census releases data only for certain locations with larger populations at one and three-year intervals. This is because, since the ACS is a sample, its reliability depends on sample size.

So on Dec. 14, 2010, the Census Bureau released the first five-year file from the American Community Survey, including all the data that used to be released from the census long form. This totaled 32,000 columns with 675,000 rows of data. These data are comparable to what was compiled from the 2000 Census and allow one to answer many questions at the neighborhood level, where data are needed beyond the few questions in the 2010 census.

In summary, two things have changed:

1. The Census has been moving toward more frequent data collection for a while. Some of the stuff that used to be asked every 10 years is now being asked more frequently, providing more up-to-date information.

2. Beveridge goes on to explain a couple of issues with the American Community Survey data, one good and one bad. On the bad side: although it may be more frequent, the sample size is not as large as a decennial census, meaning that we can’t be as certain about the results. On the good side: the Census will no longer have to rely on large teams of temporary staff every ten years but will have trained professionals collecting data year after year. In the coming years, it will be interesting to see how researchers treat these new figures.

Overall, this is a reminder that official figures don’t simply happen. They are the product of particular methodologies and definitions and when these protocols change, so can the data.

Additionally, the data is easily accessible (here are the 2010 figures). I’m sure it will continue to get easier to access and analyze the data. This is good for democracy as it is relatively easy for citizens to see the current status and changes in their nation. I wish more people could or would use this data frequently to better understand their surroundings.