Roth (2009) Uncertainty

Uncertainty is a topic that I’ve always wondered about in GIS, especially when classifying an area from a raster grid that inherently has to have error if each pixel spans 30m squared in most LANDSAT images and DEMs. I was intrigued to find out uncertainty is an academic subject in GIScience literature, as well as the many issues that one runs into when looking at uncertainty in a GIS lens. I find Roth’s overview and critique of several typologies in uncertainty essential to the paper, and although there’s a lot to draw from it, one can pick and chose aspects from these definitions to try and grasp this convoluted (and ironically uncertain) topic.

I find Roth grasps the importance of uncertainty, and how it’s conveyed to the map interpreter through the qualitative research done with his focus groups. Comments like “You just have to assume the line you draw on the map is a hard and fast line … you’ve got to put the line somewhere”, and “If you put uncertainty on a map, it would probably draw undue attention” really struck me. I find this shows the disconnect between map maker (who plays the Columbus role in a sense, stating where things are), and the map reader who blindly trusts these maps are accurate, despite not fully understanding just how much of this authoritative map was made by the map maker just “drawing a line somewhere” for convenience. I feel this qualitative approach to having focus groups and coding their answers (very much a qualitative GIS technique) very interesting, and very much in sync with the authors comments on data quality and uncertainty, as you can interpret these answers in several ways.

All in all, I feel papers like this should be more prevalent, or at least have aspects transfer into different realms of GIScience as it’s paramount to understand when creating data that others will use in decision making. I feel that even if it may draw unwanted attention to your uncertainty and influence how decision makers view it, it should be noted that maps lie, as there’s often a blind trust associated with where things are when presented to people (both from a GIScience background and not).


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