# Local view: District's student density map doesn't tell full story

## There was a small book I was required to read for a public-health class at the University of Minnesota Duluth. "How to Lie with Statistics," by Darrell Huff, gave me a new perspective on persuasion and how numbers can be manipulated to back up un...

There was a small book I was required to read for a public-health class at the University of Minnesota Duluth. "How to Lie with Statistics," by Darrell Huff, gave me a new perspective on persuasion and how numbers can be manipulated to back up untruths.

Recently, I went to the Duluth school district's Long-Range Facilities Plan website (chooseduluthschools.com) because I wanted to see the map the News Tribune raved about in its June 9 editorial about building schools near student density centers (Our View: "Makes sense to build schools near students").

I had seen the map before. It was included with the Environmental Assessment Worksheet put together by the district and Johnson Controls for the construction of a

western-Duluth middle school. The map extended along the waterfront (even into the water!) and up the hillside, with shades of black for higher student density and white representing lower student density. Around the eastern middle school site, the Ordean site, Denfeld High School and the western middle school site, the shading was "so black it's as though ink wells spilled across them," as the editorial noted. Two K-12 student density centers also were tagged east and west of a "secondary boundary."

The map provided pretty substantial evidence to build and remodel schools close to where students are.

Or did it?

There is a function in Geographic Information Systems, or GIS, called "spatial interpolation." It's an extension of map-making software used to create a statistical surface rather than a representation of a physical surface, as a new map layer. This process uses points of known value to estimate values at other points with no recorded data. This map surface can then be displayed with various options, one being shading, by the conversion of point data to a grid surface just like pixels in an image. Many of the parameters of this function are at the user's discretion.

The original points were given an asterisk-referenced explanation, although I saw no asterisk on the district's map. It stated, "The density analysis is based on the concentration of current K-12 student location," In GIS, point locations are a geographic position or address. Many proximal points can speak for themselves as dot density without conversion to a statistical surface with shading.

Unfortunately, with regards to the western middle school, even the original point locations used are potentionally irrelevant. Two years of construction for the western middle school means we should be considering K-6 student point locations only. Certainly this more specific data is available and worthy of use with a \$33 million project.

The school district recently released information of analysis of where some K-6 students fall along achievement lines: At Laura MacArthur and Nettleton/Grant elementary schools, more than half of the students aren't meeting math standards. At Morgan Park Middle School, About 20 percent of students aren't meeting reading standards.

Contrary to the stereotyping in the News Tribune editorial, I inform, not with a hidden agenda to save Central High School, but because of the 22.49 acres of undeveloped land that will be disturbed to build the western middle school. Green space defines this city, draws living things and enriches our existence on this fragile planet. When we give it up to development, we steal from ourselves and those to come.

The need for more consideration of the environmental costs of building the western middle school is the impetus behind an appeal filed against the Duluth Planning Commission ("Lawsuit opposes new western Duluth middle school," April 28). The planning commission voted against the need for an Environmental Impact Statement for the western middle school project. An Environmental Impact Statement would encourage more consideration of the environmental costs of the project and would introduce new and, hopefully, more accurate information.

Linda Ross Sellner of Duluth holds a bachelor's degree in geology and land-use planning, issued by the University of Minnesota Duluth in 1996. Also, she is certified in Geographic Information Systems and is doing research for the University of Wisconsin-Superior.