How Accurate is Too Accurate?

By Jeffery Robichaud

In the world of GIS, accuracy is one of the names of the game. A map is a two (and lately three) dimensional representation of the earth as well as important features found in our environment. We expect maps and the underlying geospatial data used to develop maps to be accurate. In fact we expect them to become more and more accurate as time passes due to advances in technology. Older GPS units used to be notoriously inaccurate, with an accuracy and precision that sometimes could literally be described as in the ballpark, but many of today’s units have sub-meter accuracy. There will always be issues associated with accuracy (or at minimum the illusion/perception of accuracy as Casey previously detailed), but are there situations where too much accuracy is a bad thing? Yes.

If you have ever perused BingMaps or GoogleEarth you know there are certain spots across the country where imagery is not as accurate as it could be. For instance in Washington, DC everything becomes pixilated at the corner of 17th H St NW, not because one moves into the world of Minecraft (if you are old like me…ask your kids) but because of homeland security concerns. I used to drive down 17th when I lived in the Northwest section of DC, and believe me it’s there.

And a quick Google of thoughts and comments on Google Streetview will yield you a lively discussion on issues of privacy, oftentimes because of how accurate or inaccurate images can be. In fact I understand that companies like Google and Microsoft go to great pains to ensure anonymity by fuzzing faces, license plates, and other personal information.

Homeland Security and Privacy are easy to point to as necessitating less accurate information for public consumption but what about the environment and natural resources? Is there ever a need to fuzz data?

Actually there is a data set that is just as important for those of us who care about flora and fauna; the locations of threatened and endangered species throughout the United States. Their locations and ranges are important for federal and state organizations charged with protecting and restoring populations in accordance with the requirements of the Endangered Species Act (ESA). But the presence of exact locations in the hands of individuals with less than scrupulous intentions could result in purposeful takes of species (what the ESA euphemistically calls the killing/harvesting of an endangered species). Thankfully, governance of this sensitive data is tight and is coordinated through an organization called NatureServe. Not all countries are so fortunate to have a coordinated program looking out for endangered species sightings. In the past, well intentioned tourists to Africa have blogged/tweeted about their encounters with endangered mammals, providing poachers with timely and sometimes fairly accurate locational data as well as pictures documenting the whereabouts of Elephants and Rhinos. This Story ran on NPR last December about elephants in Tanzania. Hopefully Social Media continues to be used for positive purposes especially when it comes to protection of human health and the environment.

Jeffery Robichaud is a second generation EPA scientist who has worked for the Agency since 1998. He currently serves as Deputy Director of EPA Region 7′s Environmental Services Division. Jeff freely admits to not “getting” Minecraft even though his kids have it on every device in the house. He still thinks of the Creeper as a villain on Scooby Doo.

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