Session 9 Reading Response: How do we map uncertainty?

The Columbus Landfall reading is a pointed account of historiography that addresses how we think about uncertainty in the context of history and historical mapping. I was surprised how sure each historian was of their account of Columbus' path, how biased their approach was, and then how much vitriol they were met with when the next historian came along. It seemed like many started with a specific route in mind, and then worked to get Columbus' journals to match with their route. Each criticized the other for a "lack of impartiality and balanced judgment and then produced a drastically difference version of the route.

In reality, there is no "right answer" for those hoping to accurately represent Columbus' journey. How, then, can historians and others convey both their conclusions and uncertainty about those conclusions? As a person with academic training in both history and statistics, I have often marveled at the threshold of evidence that historians need to declare "truth" compared to the (much higher) threshold in statistics. Without offering judgment on which is more valid, I do think that academic history could use more ways to talk about uncertainty. Historical cartography may be the most extreme case of this: maps seem to make uncertain things certain. In the examples presented in the reading, there were question marks, no alternative routes, and no dashed lines. Columbus took one route and one route only, and these historians presented their finding as the only conclusion.

NYC's flood maps face some of the same challenges: while the maps themselves represent a probability, they appear to be unimpeachable markers of the places that will flood and the places that wont flood. Like Columbus' journey, we have certain clues as to where to draw these lines (elevation, past flooding, drainage, etc), but at every point there is uncertainty. Unfortunately, there is not yet a clear way to represent this uncertainty (which also differs from place to place). The result is a mischaracterization of data - one that has sent residents, FEMA, and city government into a 10-year debate that doesn't seem to be ending soon.

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