In How to Lie with Maps, Mark Monmonier warns that map readers “must watch out for statistical maps carefully contrived to prove the points of self-promoting scientists, manipulating politicians, misleading advertisers, and other propagandists. Meanwhile, this is an area in which the widespread use of mapping software has made unintentional cartographic self-deception inevitable.”¹

So which of these two scenarios—careful contrivance or unintentional self-deception—is at play on the Georgia Department of Public Health’s COVID-19 daily status report page?

https://twitter.com/andishehnouraee/status/1284237474831761408

Twitter user @andishehnouraee notes the difference in scale between two county-by-county COVID-19 maps of Georgia. The earlier map maxes out at 4,661 cases per 100,000, the later (and as of this writing, current) map maxes out at 5,165 cases per 100,000. As they point out, there has been a 49 percent rise in total COVID-19 cases between the two maps, but you wouldn’t know it at a glance, because the scales have changed in the meantime.

Is this, as @andishehnouraee suggests, a concerted attempt to hide the severity of the outbreak in Georgia—or, as T. J. Jankun-Kelly thinks might be the case, something that happens when you max out the old scale. In other words: bad faith or bad design? (Or both: it can be both.)

Update 19 Jul: See Twitter threads from Darrell Fuhriman and Jon Schwabish disagreeing with critiques of the Georgia Public Health maps. It’s worth clarifying that only one map is ever viewable at the website: the map’s scale has changed over time, but it’s not like they’re side-by-side except in @andishehnouraee’s tweet.

Update #2: See Jon Schwabish’s blog post critiquing the data visualization critique in more detail.

1. Mark Monmonier, How to Lie with Maps, 3rd edition (University of Chicago Press, 2018), p. 153. Reviewed here.