by Waterluvian on 2/27/20, 8:59 PM
As someone with too many GIS degrees, I feel a level of cathartic release in reading this and thinking that laypersons might be able to improve their map making skills, avoiding some of the more serious cartographic gotchas. It was well-written. The beauty of the ubiquity and greatly-improved UX of modern GIS tools is that everyone can dive in to doing geospatial analysis and building static and dynamic maps. It also means people can accidentally author very misleading visualizations.
Despite this ESRI-backed article on the subject, I think the popular ESRI-driven map dashboard for Coronavirus[1] has a major flaw that violates the crux of this article. Dot density maps _MUST_ be set to scale relative to your map scale, or else you get nightmare scenarios like this one[2]. This is doubly true if the dots are varying in size (which I also think is a fundamentally terrible representation, because people suck at mentally comparing areas). If I were to modify it, I would probably use a choropleth-like representation. Keep the dots equally sized and colour them different shades of red. That way nobody's brain will mislead them into thinking "this larger circle means a larger area is all infected."
[1] https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.h...
[2] https://imgur.com/NPhEzk7
by smacktoward on 2/27/20, 7:16 PM
I can't count the number of times I've looked at a data visualization and wished I could sit down with the person who made it and read an Edward Tufte book to them. There's just so few good examples out there of data visualizations that respect basic principles of visual communication, like the ones outlined in this article. They generally seem to aim more for visual
impact (like the useless 3D display in the article, which you've gotta admit is striking) than for
clarity, which I guess is understandable but is still too bad.
(And as long as I'm griping, don't get me started on all the people who think a wall of text slapped into a PNG constitutes an "infographic.")
by danso on 2/27/20, 7:29 PM
Very nice and well-written writeup. Here's one graf that randomly provoked some thoughts:
> But looks can be deceptive. The fact that it looks okay is hiding a dark secret that, if you’re not aware of the fact, won’t even get noticed. The map is using totals (absolute values). There are very very few golden rules in cartography but this is one of them: you cannot map totals using a choropleth thematic mapping technique. The reason is simple. Each of our areas on the map is a different size, and has a different number of people in it. These two innate characteristics of all thematic maps means you simply cannot compare like for like across the map.
> The label tells us that Hubei region has over 65,000 cases of coronavirus. It sounds a lot. But does Hubei have 100,000 people, or possibly 100,000,000 people living there?
I definitely agree with the author: that there are very few "golden rules" in visualization, and that not depicting absolute numbers in a choropleth map is one of them. However, the author does an excellent job (with a bar chart and revised map) showing how this anti-pattern severely obfuscates how much the Hubei region is an extreme outlier.
by at_a_remove on 2/27/20, 9:09 PM
The difficulty I always thrash around with is: proportional by area or proportional by population? I used to do some crime maps and some areas would look quite crime-ridden ... because they were areas with very little population, as the census counts it, like parks and such, so the crime would look rather high. So dividing by population isn't the cure-all, but it beats nothing. For giggles, I would do crimes in a given region, crimes in a region divided by that area, and crimes in a region divided by the population in that region. Very different-looking results.
I have often considered dividing by some kind of combination of area and population, but even that seems not quite right. Disregarding "victimless crimes," much crime is interactive: two or more parties must be involved, therefore the population ought to have some kind of exponent attached to it, like particles bouncing against one another in a container.
I never did puzzle this out, I am sure brighter minds than I would have come to some conclusions.
by Grue3 on 2/27/20, 7:43 PM
The number of cases per people statistic is silly. It might make sense when the virus is common around the world, but when it's just spreading the number of cases itself is more important. For example if you detected 100 people infected with a virus in some region, does it matter if it has 200 million people (Uttar Pradesh) or 10 million (Lombardy)? These political divisions are arbitrary anyway.
by namirez on 2/27/20, 9:42 PM
This is interesting but sadly their service is not accessible in Iran, one of the hardest hit countries by Covid-19, not due to censorship by the Iranian government, but due to server-side blocking of IP addresses originating from Iran. The reason: US sanctions!
https://twitter.com/ARTICLE19Iran/status/1231895623789576192...
by yorwba on 2/27/20, 8:09 PM
Also worth considering whether you really need to aggregate all cases in the same province. If you can get higher-resolution data, use it. (E.g. for each prefecture in Hubei province:
https://news.sina.cn/project/fy2020/yq_province.shtml?provin... Their visualization isn't great, but someone else could use their data to do a better job.)
by tasogare on 2/28/20, 8:56 AM
OP wants to give lesson about mapping yet include Taiwan in a map of China. Seriously? He should learn about geography and country borders first before writing any blog post.
by panic on 2/27/20, 7:34 PM
I actually love the 3D map despite how cheesy it is. It shows how much of an outlier Hubei is better than any of the 2D maps do.
by peteretep on 2/28/20, 7:17 AM
A map seems a terrible base layer for any information that isn’t trying to show proximity or proportional landmass. Seems ridiculous to mess around with talking about a projection when it’s still showing provinces related to their shape and size, which is worthless information here. Why not just use a population cartogram as the base?
https://m.facebook.com/457568574373257/posts/this-is-a-popul...
by ggm on 2/28/20, 3:11 AM
If we get 1+ in Alaska and Greenland, for most peoples immediate visual sense "OMG OMG OMG look how much of the map is now .. red"
Because Mercator.
Likewise in soviet russa.. map owns you. How much of the cold war might have been put back to bed, by a better map projection?
by thedance on 2/27/20, 9:51 PM
If anyone from Esri ever reads these comments, please for the love of maps stop using scroll wheel and pinch to move maps north-south. Nobody, literally nobody, has ever wanted that, literally never.
by bilekas on 2/27/20, 11:45 PM
I was thinking today that it would be a good use of that map data thats recorded from our phones GPS for mapping the route of the virus.
Hypothetically: If all infected submitted their map data for the last few days (annonymously - no need to identify people) and all of that data was plotted over maps, you could identify the routes and direction of infections.
I don't know if it would be anything more than an interesting visualisation of the data already collected, but the comment mentioning Edward Tufte really got me thinking how to visualise the data we have properly.
We haven't seen something spreading like this in my lifetime anyway and at the same time, we've never had so much data on ourselves in my lifetime either, might be a good time to put it to good use for once.
by user5994461 on 2/27/20, 7:28 PM
Incidentally, I made a demo app with proportionally sized circles like they suggest, and it allows to move day-by-day to see the progression.
https://coronaprogress.com/I am gonna update the numbers for today.
by alanh on 2/27/20, 8:51 PM
I wish people would stop treating “coronavirus” and COVID-19 (or SARS-CoV-19) as synonyms. They are not. There are many more coronaviruses.
by pnako on 2/28/20, 4:21 AM
by aeontech on 2/28/20, 2:12 AM
by ohmyblock on 2/28/20, 8:37 AM
Is there a map with the exact location (cities) of outbreaks covering Europe? I can only find Country based maps
by xwowsersx on 2/27/20, 7:59 PM
I'm unclear as to whether we should be seriously concerned about Coronavirus in the US at this point. Are there preparations I should be making or precautions I should be taking? People have been WhatsApping me articles about face mask shortages, but I don't know if this is just scaremongering.
by Eliezer on 2/27/20, 8:20 PM
For this application I think you really want one of those maps that equalizes area and population!
by lawrenceyan on 2/27/20, 9:11 PM
As someone living here in the Bay Area, I have little to no interaction with the current ongoing Coronavirus outbreak. Why are Asian countries taking such dramatic measures right now?
To be willing to take on such an economic drain in order to do so makes it seem like they're treating the virus like a potential pandemic. Are the death rates for the current coronavirus outbreak substantially higher than the regular flu? What else am I missing here?
by heartbeats on 2/27/20, 9:26 PM
>We’re mapping a human health tragedy that may get way worse before it subsides. Do we really want the map to be screaming bright red? Red [...] can connotates [sic] danger, and death, which is still statistically extremely rare for coronavirus.
This really seems like a case of "it's not a bug, it's a feature". It may be rare (so far, anyway), but few would argue "danger and death" is an inaccurate characterization.
by eliben on 2/28/20, 4:26 AM
What caught my eye is that in Hubei province, which we all imagine as a zombie apocalypse now, only ~110 out of every 100,000 got infected, and at this point the new infection rate is going down.
Which is quite amazing, given that the virus was spreading there for weeks (at least) without anyone being aware of anything before all the mess was uncovered and announced.
by daveslash on 2/27/20, 8:15 PM
If you enjoyed this post, then I'd
really recommend
"The Wall Street Journal Guide to Information Graphics: The Dos and Don'ts of Presenting Data, Facts, and Figures" by Donna Wong.
http://www.donawong.com/by Aeolun on 2/28/20, 1:25 AM
Even if people knew this, they’d still use red and make a heatmap. Gotta get those pageviews.
I really like the article though.
by PeterStuer on 2/27/20, 7:56 PM
by gchokov on 2/28/20, 11:35 AM
by inferiorhuman on 2/27/20, 5:31 AM
Thanks for posting this, and not just because it's immediately relevant. ESRI goes over some really good guidelines for visualizations as well as interpreting them that can be applied to anything you see in e.g. the New York Times.
by mkj on 2/28/20, 12:46 PM
A proportional symbol map doesn't seem very useful. It's meant to scale by area of the symbol, but at least personally I find myself comparing the diameter of the symbol.
Maybe thick 2d lines would work better?
by crmrc114 on 2/27/20, 7:20 PM
Its funny that for a software company ESRI basically owns the GIS market. I really liked how this article goes over processing a projection and communicating reality w/o panic and sky is falling insanity.
by sanguy on 2/28/20, 11:10 AM
This is ironic from ESRI. Nothing they do is responsible - but all they do is for domination and control of the industry.
Jack would happily watch people die if it sold more licenses.
by c3534l on 2/28/20, 6:34 AM
I'm not convinced the 3D map isn't the most illustrative and compelling graph of them all. It says way more than the sprinkle of hard-to-parse dots does.
by Thorentis on 2/27/20, 9:24 PM
In what data visualisation situation would you use anything other than an area equal map? What advantage does the web projection offer over area equal?
by btomtom5 on 2/27/20, 9:28 PM
As a point of reference for how deadly the corona virus is, you are more likely to die by murder in New York city than you are to die by corona virus in Hubei, assuming a death rate of 2.5 percent. The murder rate in NYC is 5 per 100K whereas the infection rate in Hubei is 111 per 100K.
Edit: This isn't really a fair assessment. See the comments below.
by microcolonel on 2/28/20, 5:06 AM
>
It can easily connotate danger, and death, which is still statistically extremely rare for coronavirus.No, no, no. 2.2% (conservatively) is not extremely rare for a virus that we have been helpless to stop from spreading to every continent except Antarctica.
by tidenly on 2/28/20, 3:28 AM
Really interesting article.
Ironically, though, an article about mapping responsibly is using a map of China with Taiwan on it.. That's a pretty huge oversight.
Edit: Downvote all you like guys - but Taiwan is an independent nation. :)
by perennate on 2/27/20, 7:19 PM
The article raises several good points, but inexplicably includes Taiwan in a map of coronavirus in China. Might as well include North/South Korea as well.
by ska on 2/27/20, 8:28 PM
Good data visualization is hard, and most mapped data that isn't geographical in nature is poorly done (cue xkcd cartoon).
Some of the point in this discussion are pretty good, but the thing I missed is a good commentary on the temporal nature of anything like virus spread.
by justlexi93 on 2/28/20, 1:59 AM
It is scary knowing that the number of cases increases.
by tzvsi on 2/28/20, 1:33 AM
Ok, I have doubts. You can literally put ", Responsibly" behind anything and it sounds legit.
Google, Responsibly
Facebook, Responsibly
AirBNB, Responsibly
Prove me wrong.