MCDC Highlights


MABLE/Geocorr and CAPS

These are two of the Missouri Census Data Center's most venerable and popular web applications. Both have been around for over ten years (the first version of Geocorr was in 1996) and both are now available in multiple versions. To help users to choose the best version for their needs, we have created a pair of index pages for the two applications.

The CAPS index has brief descriptions of and links to the current four versions of the CAPS application (as follows):

  • ACS Data. This is the current production version that works with the latest available data from the ACS (American Community Survey).
  • ACS Data-Beta. The beta test version is similar to the production version in that it works with the same underlying ACS data. But it has some important new features. The most significant change is in the algorithm used to include/exclude a geographic unit (census tract or block group) within a circle. This module accesses a block-level file with coordinates and 2010 population counts and uses that infomation to estimate the portion of the unit's population within the circle. It then applies that allocation factor to all the data for that unit. This is referred to as BBIA — Block Based Inclusion Algorithm — and is highly recommended for small radii (under 5 miles). This has been the beta version since April of 2016 and appears to be stable and reliable.
  • 2010 Census Data works with census block-level data from the 2010 census (Summary File 1, for those familiar with Census data products). This is a good choice if you want just basic demographic data (age, race, sex, Hispanic, etc.) and can live with the fact that this is 2010 data (starting to get old).
  • CAPS Classic is the orginal version of the application that works with data from the 2000 decennial census. Unlike the 2010 census version that has limited data ("short form" only), these reports show a much richer set of data taken from Summary File 3.
  • Batch CAPS is different from the other web-based applications. This fee-based service is for users who have large files of point-based data (typically address or coordinate files). The CAPSacs service is recommended. It makes use of the same BBIA logic as the latest ACS web module. The output is a CSV file suitable for importing into Excel.

Users should be aware that the "beta" version of the application has been working without any reported problems for the last six months. It has some significant enhancements, especially for users working with smaller radii for their circular areas.

The new Batch CAPS option was created partly in reponse to numerous instances of users running hundreds or even thousands of instances of the application in a short time, creating load problems on the server. We ask users to limit their use of our web applications to no more than 500 a day. Users who consistently exceed that limit may be put on a deny-service list.

The Geocorr index provides similar links to the various versions of our MABLE/Geocorr application. It also has a section with links to doumentation for the application(s).

Presentation: Accessing ACS Data on the MCDC Web Site

The power point file for John Blodgett's presentation at the 2017 ACS Data Users Conference (Alexandria, VA, May 11-12) has been posted to our tutorials directory. There is also a companion page with links to the various pages cited in the presentation. This is a very brief presentation (15 minutes), so it's a pretty light overview of of our ACS-related resources.