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Do you know why John Snow is an important character in the data storytelling world?

“The one from Game of Thrones”, you ask?

No, Dr. John Snow who lived from 1813-1858 in London and is considered the father of modern epidemiology. In contrast to his fellow scientists, he believed cholera not to be airborne but the outbreaks to come from contaminated water. 💦

When another cholera outbreak in Soho, London🇬🇧 occurred, Snow used a map to visualize the death toll and location. It seemed that the pump on Broad Street was the epicenter of the break-out. He realized that from the 83 registered deaths, 10 people actually lived closer to a different pump. After in-depth investigation on these “outliers” he found, that 5 of them still preferred the pump on Board Street and another 3 had been school kids, drinking from the pump on Board Street on their way to school.

Another anomality struck him: a nearby brewery with 70 employees and a workhouse with 535 inmates were located near by the pump but had no major casualties. Snow found out that both had their own private well and therefore did not rely on the pump on Board Street.

👉🏻 With this data and the map, Snow was able to convince his colleagues and authorities of his theory and findings and new precautionary measures were implemented.

By the way, it turned out, that the dirty diapers of a baby that had died from cholera were causing the contamination of the pump.

Your data presentation can have a great impact on humanity!

Happy presenting!

Thanks to Brent Dykes for this and many more stories in his great book “Effective Data Storytelling – How to drive change with data, narrative, and visuals”

(Picture Source: and HBO)

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