In this six-part series, The Nature Conservancy's
LANDFIRE Program Lead
Jim Smith looks at spatial data with a keen eye and offers important insight and advice.
In his final blog of the series, "LANDFIRE Agreement Results," Jim ties all five commentaries together, and offers an overview regarding the LANDFIRE data suite.
More Than Catchy Number -- How does traveling from New York City to San Francisco on I-80 relate to data quality? In how many ways does calculating the mileage between spots like Appalachians, Great Plains, Rocky Mountains, Great Basin, or Sierras describe the essence of a trip? Jim takes these questions and adds references to wine types and alcohol percentages in order to advise data producers on how they can help users apply data correctly.
Overall Agreement -- Looking at the way to obtain quantitative estimates of spatial data accuracy, Jim parses seven simple, practical assumptions being made by those using percent overall agreement that are often glossed over or forgotten and blows them out of the water.
Contingency Table/Error Matrix -- In order to clarify concepts, Jim offers a four-category contingency table (a cross-tabulation of what the reference data indicated at a specific location versus what the map indicated at that same location), and shows how it is used to reach overall agreement metric.
Understanding the Usability of a Map -- Jim’s been building up to this one: a two-sentence summary that takes nine bullets and several paragraphs to explain. Preview: he defines a map producer's responsibility, and advises users to spare no effort when it comes to understanding and applying map information in terms of applications.
Local vs. Non-Local Accuracy -- Point of view matters!
LANDFIRE Agreement Results -- Jim's caveat: what is important and useful to me may be of no interest to you, so in my version of Stop, Drop and Roll, I will ask you to
Visit, Download and Review assessment results yourselves.
More on data: other commentaries by Jim Smith