Conclusions  

Census data users are accustomed to use a single data set every ten year and to see linear comparisons between censuses. There has traditionally been little or no use of available quality measures to evaluate the decennial census. The strength of the ACS is the wealth multiple annual data sets. Our challenge is to assess these multiple data sets and the quality measures which we’re less familiar with to use those data effectively. There is a serious hope that the ACS will accurately portray the size, location, and characteristics of the population of California and that selected ACS variables such as vacancy rates, persons per household, and the question on residence one year ago can be used in the future to inform and improve the State of California’s population estimates.