The Missouri Census Data Center has created a family of related applications that provide access to distilled demographic summaries of a wide array of geographic areas based on the results of the 2000 and 1990 decennial censuses. Each application comprises a report-generating web application that accepts standardized parameters (mostly geographic codes) and dynamically generates a profile (a report using HTML) based on those specifications. These reports are sent directly to the web browser. In addition to the demographic data, they include a series of hyperlinks to metadata and related applications. These web applications are all written using the SAS software package.
The underlying datasets that power the applications are organized within special directories, and direct access to the data is available via a web application called Uexplore.
The MCDC has developed several of these profile products. Why so many? Partly because the Census Bureau delivers most of the data from a decennial census in two basic kinds of summary files:
Because the data from the short form is released about a year earlier than the data from the long form, we usually have to create data products based on the short form earlier than those based on the long form. The short-form data is also available at finer units of geography (down to the block level) that the long-form data. Our profile products usually come in pairs, with one being based on short-form data and the other based on long form data. The specific data products (summary files) released by the Census Bureau corresponding to these two kinds of data are "Summary File 1" (complete count) and "Summary File 3" (sample data). There are also summary files 2 and 4, but we do not use those tabulations in our demographic profile products.
The other defining dimension for these data products is the year or years of the data. We have two products that contain data only from the 2000 census, one that has data only from the 1990 census, and two more that are trend reports containing comparable data items for both decades.