(Editor’s Note: To mark the important opportunities and diversity that exists within the data economy, the iSchool and many others from across the world have joined together to present the second annual Data Innovation Day. We offer this article to celebrate the day as well as a reminder of the profound effects of data innovation throughout history.)
The year is 1854, and you’ve been sent on a simple errand. Your family needs water, and so you make your way to one of the neighborhood water pumps—the pump closest to your house. You fill a bucket with water, and return home. You don’t know it yet, but in choosing to use that particular pump, you’ve just determined whether your family will live or die.
This is the story of the English physician John Snow and the map he created during a devastating cholera outbreak in London in 1854.
On the one hand, it’s a complicated story, inhabited by mysterious, microscopic organisms, a young and crowded metropolis strangled by dung heaps that stood as tall as houses, and factions of scientists and civic leaders at odds over how to eliminate an invisible killer.
On the other hand, it’s a very simple story. About data.
According to Professor Joe Janes, producer of the podcast series Documents That Changed the World, the John Snow map was a compelling topic because “it’s the Nineteenth Century version of big data; coalescing and condensing new and multiple streams of information — textual, numerical and observational — in ways they never had before, to make them far more useable.”
In this episode of the popular podcast series, MLIS grad Andrew Brink tells the story about Snow’s attempts to convince others that cholera was spread by contaminated drinking water rather than by the popularly accepted miasma (air) explanation.
The breakthrough came when he used a London street map and graphed the number and locations of cholera deaths next to neighborhood drinking water pumps. The result clearly showed the Broad Street pump to be at the epicenter of the cholera outbreak: Proximity to this well was directly proportional to mortality risk. The pump was closed, the epidemic abated and the results helped give rise to the discipline of epidemiology.
Why did Brink choose this example for the series?
“The map was a way to visualize and simplify a wide range of data sources that were just starting to emerge: statistical, narrative and observational. If you just had one piece of the puzzle, you weren’t going to solve the mystery of where the cholera was coming from. It took a lot more than just the map, but the map was the key to changing people’s minds about how disease was transmitted and what could be done about it.”
About Documents That Changed the World
DTCW is an ongoing podcast series by iSchool Professor Joe Janes that explores the compelling stories of various “documents” from throughout history. Each of the documents is a product of its time and prevailing technology, as well as an artifact of human activity, emerging from its social context to have a significant impact. The series is available for free through iTunes.