NACIS 2015

Are You Being Served? Debunking Highway Service Claims through Early 20th Century Population Distribution Reconstruction
Jenny Marie Johnson, University of Illinois at Urbana-Champaign
James V. Whitacre, University of Illinois at Urbana-Champaign
During the Good Roads movement era, the National Highways Association promoted the creation of a National Highways network that would be built and maintained by the Federal government. State maps were published illustrating the network and claiming improbable population service levels. Using 1910 Census data, these inflated service estimates can be disproven using geometric and arithmetic techniques explored and developed to overcome the lack of era-appropriate, in particular minor civil division, Census geography.
https://github.com/whitacrej/ILGISA-GIS-Python-Workshops-2015

Census Time Series Tables from NHGIS: An Overview for Cartographers
Jonathan Schroeder, Minnesota Population Center, University of Minnesota
The National Historical Geographic Information System (http://www.nhgis.org) provides free online access to summary tables and GIS boundary files for U.S. censuses from 1790 to the present. In recent years, NHGIS has begun releasing time series tables, which link together comparable statistics from multiple censuses in customized downloadable bundles. There are now thousands of time series available, organized into hundreds of tables, covering statistics from the 1970-2010 censuses and the 2012 American Community Survey. New tables released this year provide 2000 and 2010 statistics for 2010 census areas, using an advanced areal interpolation method to refine 2000 estimates where boundaries changed between censuses. I provide an overview of current and planned NHGIS time series features, focusing on ways time series tables can simplify and augment census mapping endeavors.
https://speakerdeck.com/nacis/jonathan-schroeder-ngis-time-series-tables

Census Mapping Mashup
Paul Hunt, University of Nebraska - Omaha
By mandate, the United States Census Bureau compiles and distributes data on the U.S. population. Initially made available on paper, the data has been available in computer form since the 1970s. Recently, through open data initiatives, the Census Bureau has made it possible to access and analyze this data with simple web-based services. These tools allow for the access and retrieval of data on-the-fly. Cloud-based methods of mapping can then be used to display the data without downloading the census data. With the ability to access large amounts of data, custom web mapping applications can be developed using readily available APIs for both spatial and non-spatial data. This new method for requesting and processing data from the U.S. Census Bureau is described, along with the development of an interface that allows user-defined requests and mapping of the census data.
https://speakerdeck.com/nacis/paul-hunt-census-mapping-mashups

Where the People Are: A Dot Density Metaphor for Cartogram Construction
Barry J Kronenfeld, Eastern Illinois University
Cartograms have enjoyed growing popularity in recent years due to algorithmic construction tools. A mainstay of these tools is a transformation grid relating geographic space to cartogram space. Typically, a regular grid is constructed in geographic space, and this grid is stretched, compressed or otherwise deformed to create “cartogram space”. This approach, however, leads to poor representation of small densely populated regions – the very regions of interest to cartogram readers. More accurate results can be achieved by reversing the transformation grids. The reverse approach leads to a simple metaphor: grid nodes on the source map represent a constant number of people and can be likened to dots on a dot-density map. I will demonstrate user-friendly software for manual construction of cartograms using the reverse transformation. Examples of cartograms constructed using this software are shown that provide more accurate results than algorithmically produced cartograms, especially for small, densely populated regions.
https://speakerdeck.com/nacis/barry-kronenfeld-cartograms