As summer rolled into fall and the data from the 2005 American Community Survey just kept coming, one thing became clear: Its maturation will be slower and more difficult than even the Census Bureau anticipated. This year's release, the first of the full national sample of three million households per year, is already the sixth in the series stretching back to the Census 2000 Supplementary Survey. ACS won't emerge in full form until 2011.
In journalism, that's almost geological time. ACS has been changing all the time. This year, the data changed significantly from last year. The same thing will happen in each of the next two years. For example: The 2005 data was produced from a nationwide sample that included all states and congressional districts. PLUS: This allowed comparisons from place to place that could never be made before. CAVEAT: comparisons to earlier years were often suspect.