Lesson on Infographics from John Snow (no, not that Jon Snow)

Jan 12

Data visualization. Information architecture. Infographic.

These are buzz words in the modern communications environment where the ability to show processes, statistics, and messages in a visually pleasing way has become communications gold. The growth of communications platforms like Facebook and Twitter has driven the value of graphic content, including infographics, which can be shared with the click of a button.

But what makes a good infographic?

In his 1983 book The Visual Display of Quantitative Information, data visualization pioneer Edward Tufte says that ‘graphical displays’ should:

  • Show the data;
  • Induce the viewer to think about the substance rather than about methodology, graphic design, the technology of graphic production, or something else;
  • Avoid distorting what the data have to say;
  • Present many numbers in a small space;
  • Make large data sets coherent;
  • Encourage the eye to compare different pieces of data;
  • Reveal the data at several levels of detail, from a broad overview to the fine structure;
  • Serve a reasonably clear purpose: description, exploration, tabulation, or decoration; and
  • Be closely integrated with the statistical and verbal descriptions of a data set.

 

He also claims that: Graphics reveal data. That’s an important point.

I’ve always appreciated the power of a good infographic, but during a recent trip to London I got a fortuitous lesson on the history of the tool when I was introduced to John Snow.

Way back in the 1850s (when, forget Facebook, the first transatlantic telegraph cable was laid), Snow was a skeptic of the then-dominant theory that diseases such as cholera and bubonic plague were caused by pollution or “bad air.” The germ theory of disease had not yet been developed, so Snow did not understand the mechanism by which the disease was transmitted. He first publicized his theory in an 1849 essay, On the Mode of Communication of Cholera, followed by a more detailed treatise in 1855 incorporating the results of his investigation of the role of the water supply in the Soho epidemic of 1854.

By talking to local residents, he identified the source of the outbreak as the public water pump on Broad Street (now Broadwick Street). Although Snow’s examination of a water sample from the Broad Street pump did not conclusively prove its danger, his studies of the pattern of the disease were convincing enough to persuade local officials to disable the well pump by removing its handle. This action has been commonly credited as ending the outbreak.

Snow later used a dot map to illustrate the cluster of cholera cases around the pump. He also used statistics to illustrate the connection between the quality of the water source and cholera cases—showing that the Southwark and Vauxhall Waterworks Company was taking water from sewage-polluted sections of the Thames and delivering the water to homes, leading to an increased incidence of cholera. Snow’s study was a major event in the history of public health and geography. It is regarded as the founding event of the science of epidemiology.

Cool, huh?

Original map by John Snow showing the clusters of cholera cases in the London epidemic of 1854.

Original map by John Snow showing the clusters of cholera cases in the London epidemic of 1854.

Snow’s Soho infographic was simple, but brilliant. By plotting cholera deaths by household, as well as the location of the water pumps, it truly revealed the data that pinpointed the source of that cholera outbreak and identified the sewage-polluted water system as the carrier of the disease.

What else made it a good infographic? Well, by Tufte’s standards, it encouraged the eye to compare different pieces of data (volume and location of cholera deaths vis-à-vis the local water pumps). Though the map doesn’t convey the population of the area, it does show that the largest cluster of deaths was closest to the Broad Street Pump—and as you get further and further away from the pump, deaths were less frequent. In part as a result of this map, when the next big cholera epidemic threatened London, authorities acknowledged that water was the problem and told residents to boil their water. And that was the last cholera outbreak to hit London.

As a communications professional, I’ve helped produce my fair share of infographics for clients. I’ve seen plenty of excellent ones that tick off most or all of Tufte’s criteria. (Check out a few of the latest recognized in The Best American Infographics 2015, featured on Popular Science.) But I’ve also seen some bad infographics. I won’t call any out here, but these examples generally forsake the data for creativity or vice versa.

For me, Tufte’s guidelines and Snow’s work reinforce the importance of the Ogilvy twin peaks of creativity and effectiveness—a driving philosophy that we strive for creativity in the unique ways in which we help our clients solve their problems while, at the same time, focus relentlessly on our effectiveness so we have undeniable proof that our creativity makes a meaningful difference.

Not every infographic is going to save lives, but we should remember that they indeed can.

London, January 2016. Outside the John Snow pub with the plaque recognizing the location of the Broad Street Pump and John Snow’s discovery of in 1854 that cholera is conveyed by water.

London, January 2016. Outside the John Snow pub with the plaque recognizing the location of the Broad Street Pump and John Snow’s discovery in 1854 that cholera is conveyed by water.

Please note: I borrowed liberally from Wikipedia for the background on John Snow and the Soho cholera outbreak.

This entry was posted on Tuesday, January 12th, 2016 at 12:42 pm and is filed under Best Practices, Public Health. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.

3 Responses to “Lesson on Infographics from John Snow (no, not that Jon Snow)”

  1. Lauren Plowman says:

    Your timing is impeccable Junia! Working on my MPH in Social Marketing and just this morning finished a lesson on John Snow’s Broad Street pump study. Love how you’ve connected it to the power of visuals.

    And I will definitely be visiting his pub on my next trip to London.

    Cheers!

  2. Junia Geisler says:

    Thanks for reading, Lauren. When you visit the pub, check out all the photos and news clippings about Snow. Good luck with your MPH program!

  3. Khaled says:

    Great post! Thank you for restating the value of Tufte’s guidelines on graphical displays.Thanks for sharing!