Cartographic hyperbole

Just when you think we've exhausted mapping the 2016 Presidential election maps along comes another. New York Times' 'Extremely Detailed Map' presents precinct level data from the work undertaken by Ryne Rohla.

And thus, my Twitter feed went into a late night tail spin as I saw, in equal measure, exasperated cartographers bemoaning the map and political commentators and everyone else and their dog exclaiming it's sheer wonder. I offered a few comments which drew plenty of agreement, but which also had others telling me that the map wasn't made for master cartographers etc etc. No, Nate Cohn, the map is not 'as I've never seen it before'. It's not 'amazing' or 'Incredible'. No, James Fallows, the map is not 'great'. Such hyperbole simply reinforces people's beliefs because they take their lead from the sort of comments you make. Who cares what a few expert cartographers might have to say on the topic...you know, those people who are actually qualified and experienced in ways that make their perspective worthy.

So what's my beef? First off, the map is not 'wrong'. The data is more detailed than many others (including virtually all I made) by being at the precinct level and not the county, or state level. So you have smaller geographical areas. Detailed, yes. Accurate, certainly. Useful? Absolutely not because of the way the map was made. The very fact that it's made for a public not versed in cartographic wizardry is precisely why maps like this need strong cartographic editorial control. The general public is drawn in by the headline, they are told detail matters and they infer that the map must be bloody great because they are told it is.

It's a straight-up choropleth showing share of vote. Darker shades of red for a higher Republican share and Darker shades of blue for higher Democrat share. It uses a standard diverging colour scheme. Again, not fundamentally 'wrong' but the choice of map type and symbol type lead to a very particular map. A map that, visually, over-emphasizes geography.

You see, there are hundreds of small areas on the map with ridiculously low population counts which are given equal (and sometimes greater) visual prominence as other far more densely populated areas. An area that has 100 voters and 90 of them voted Republican is shown as dark red and a 90% share. Exactly the same symbol would be used for an area that has 100,000 voters, 90,000 of whom voted Republican. The differences between the number of people who live, work, and vote in each area is fundamental to the impact the resulting map has on our senses because we end up seeing a shit load of red. That much red distorts our perception of the result. It exaggerates the election results by persuading our eyes that more red equals more votes and a larger winning margin. That simply isn't true. Many small areas with a lot of people carry far more importance, electorally, than many large areas that have small population counts. And so, the map misleads, it reflects more of the geography of the country than it does of the people of the country. That huge swathe of red down the middle of the country is not a huge crowd of Trump voters, distributed as evenly as people on the two coasts, but simply where sparsely scattered people preferred Trump's pitch.

The very same data was far more eloquently mapped by The Washington Post back in September of 2017.

This map takes the very same data yet is designed to ameliorate the form. It considers the underlying problems of its distribution and the geographies it is bound by. It then reflects on how best to show the same data in a way that a person needs not to have a degree in cartography or electoral geography to disentangle the reality form the mapped form. In short, they thought about how to rid the map of misleading symbols and present a more truthful version. This, is good cartography. Where a cartographer has actively considered the impact of his or her design choices on the map, the message imbued in their choices, and the way the map will be perceived and cognitively processed.

The Washington Post map scales point symbols and uses subtle transparency shifts to take account of geographical and population distribution disparities. Same data. Fantastic map. Still plenty of red but, now, in visual balance with the rest of the map. And comparisons are what maps like this are all about. We see one place and we visually compare with another. That's how we assess our understanding of spatial patterns and the simple processing of where there is less compared with more.

Back to the NYT map for a moment because there are other problems that I honestly cannot believe we're still talking about. The map uses Web Mercator as its projection. This is flat out wrong for a map where you want, sorry, NEED, equal area to be maintained. Just dumping the map across a Web Mercator basemap is downright lazy. Alaska...

And the 3D view...holy crap map. It flips the map to an oblique angle but the map is flat. Flat as a bloody pancake. There's nothing 3D about it whatsoever. A gimmick. A pointless, and mis-labelled gimmick that ends up distorting the relative coverage of colour even more. Foreground gets visual prominence. Background recedes.

So there we have it, the latest election map. Not the best by any stretch but another clear demonstration of the vital role cartographers have in educating people to understand that what they are seeing is as much a function of the choices in map design (and laziness in not doing anything to prepare or display the data) than it is the actual data. Making maps for mass public consumption demands good cartography, not technical gimmicks. It demands you reflect on what the map will tell people through your design choices. Cartography mediates understanding. The lens of the map-maker is fundamental to how we see the world. If you choose, actively, or through ignorance, not to bother with cartography then your map is doing your viewers a huge disservice and reinforces the already pathetically poor appreciation of geography that exists in society. Think about it. Do better, and end the nonsensical cartographic hyperbole that this sort of map crap feeds.

I'll end with this...Nate Cohn trolling any and all of us who make comments on the problems of the default choropleth.

Let me be clear...I love a good choropleth map. Modify the map by adding in an alpha channel to visually mute areas with smaller populations and you've got a good choropleth. Put it on an Albers Equal Area projection and you've got a great choropleth. Alternatively, modify the geography to account for population and you've got any number of different cartograms all with choroplethic symbolisation. Do your due diligence and make the map right.

A new map in prospect

We took @wisley_dog to one of his favourite local parks the other day. Prospect Park in Redlands is a lovely spot that sits a little up the hill in south Redlands offering spectacular views across the San Bernardino valley to the mountains beyond. It's a mix of trails, orange groves, places to picnic and also houses an outdoor amphitheatre. It's also next to Kimberly Crest House - one of Redlands historic houses. At 11 acres it's not a large park.

Like many, we parked on Cajon St and entered the park by its North-East access points. There's a shady picnic spot and, as I found, a new information board which houses a new map of the park. Here it is, measuring about 3ft wide:

That's a lot of map for a small park. It kinda ruined my walk. It likely ruined Linda and Wisley's walk too as I bent their ear about the map and its problems. So let me bend your ear too and, hopefully, in the process, show you how to critique a map.

On the face of it it looks nice enough but as with anything that's dressed nicely it can often deceive. So let's deconstruct it a little and have a conversation about some of the cartographic and design choices.

The information board is located on the North-East edge of the park. You look at it facing South-West. Yet the map is oriented with North-West at the top to align Highland Ave with the top edge of the paper. This makes absolutely no sense. Fundamentally, the map is oriented incorrectly. These sort of in situ maps need to be oriented so the map is laid out as you look at the park in front of you. This map should have Cajon St at the foot of the sheet and, as you look (and wander) beyond the map you can then easily process the lefts, rights and other locations of points of interest in the park. Rotate the map and you get this which is far more useful from that location:

This is an all too familiar problem of maps on information boards like this. It simply needs the people who commission the map and those making it to have a conversation about where it's going to be displayed. It means if it's to be displayed at several locations it should be rotated accordingly but that's not difficult if you use a GIS and it's data-driven. It's also not difficult with some forward thinking as this other Redlands park map shows. The Caroline Park map is on a board on the south edge of the park. North is top and you stand looking at the map, looking northwards. Perfect. It's also a beautifully illustrated map that shows you the function of different parts of the park as well as the flora and fauna you may see.

Back to the Prospect Park map. Orientation is not the only problem. The labeling is awful because you have difficulty reading it.

Simply overprinting black text (in boring Arial) over the background is never going to work. There's so many ways of improving this. Masks, Halos, Shadows. Anything! And there's leader lines everywhere. they're unnecessary.

There's so much space on the map which makes should make lettering it an absolute joy compared to most maps. And as far as the overlooks are concerned, a symbol might be more useful and that would obviate the need for a typographic element and three ugly leader lines altogether.

So...overlook. That tells you something. It means that there's some elevation throughout the park. Yet the map displays no information to warn the casual visitor that there nearly a 100ft elevation gain between Cajon St and the highest point. A vantage point that then allows such beautiful vistas towards the San Gabriel and San Bernardino mountains (and the San Andreas Fault but I try to ignore that most of the time). OK, but there's a network of nicely paved paths right? They're all shaded grey so they're all the same?

Imagine you're a wheelchair user or struggle with walking up a moderate incline. You'd not only be frustrated that the map shows no detail of the elevation gain but, worse, many of the trails are nothing more than dirt and gravel making them almost impossible to access for some people.

By making all the paths the same symbol type the map infers they are the same. Yes, you can drive up to the parking lot at the top via Prospect Drive but you can't take your car anywhere else. You can't similarly access it from the other apparent entrance on Cajon St either. the map might not need detailed contours other other ways to show elevation but showing how elevation changes along the trails would, at the very least, be an extremely helpful piece of information.

And what of the parking to the left of the map that you can access via Highland Ave? Well, technically, you have to go through the entrance to Kimberly Crest house to get there and that has a gate that is locked at times when the adjacent park is open. Useful information, particularly so you don't get locked inside with no way out. In fact, that car park is not really part of Prospect Park at all. It's the access to Kimberley Crest House and Prospect Court as this OpenStreetMap map helpfully symbolises by specifically not including it in the green that designates the park boundary.

View Larger Map

Take a look at the OSM map again - it shows one route into the park for cars to get to the central parking lot. It shows clearly how you access it via Prospect Drive. It shows other trails inside the park differently to distinguish their use. But while we're at, it there is an error on this map too. If you access Prospect Drive from Highland Ave you cannot drive through and round the bottom edge of the park and into the Prospect Park lot that way. There's a chain across the road to prevent access. And neither OSM or the new Prospect Park map has the new footpath included between the Kimberley Crest car park and Highland Ave.

Zoom in to the OSM map. See those water fountains? Redlands can get kinda hot. Water fountains are important for dogs and humans alike. They should be on the map. The Prospect Park map has restrooms (labelled - maybe another case for a symbol?) but not water fountains. Makes the map a little partial with basic information.

And back to the map's background. At first glance the Prospect Park map appears to be a hand-drawn and painted map. I think it's based off some form of digital data (possibly even just traced off imagery). It looks OK but it could be so much better. Each orange tree gets a uniform symbol. A bit of rotation on each would make the groves look more organic and 'real'. And what about all the other vegetation? There's palms, giant mature specimen trees, a bamboo forest, seating and grassy areas to name a few major parkland types of ground cover. yet pretty much everything other than orange trees and the palms along Cajon St gets the same smudgy fill. This could have been so much more exciting with other tree species canopies or symbology.

There's also a small creek than runs between the picnic area beside Cajon St and the park beyond. Why wouldn't you mark that? It has 6ft walls despite not always having much water in it. It's hard to miss in reality yet the map makes no mention of it. It's a prominent feature yet all the map has to indicate anything is a bridge label next to a cross-hatched rectangle that is presumably supposed to represent the bridge itself. A bridge over what?

Possibly a spelling mistake too...lower left 'Orange trees on Terrance'. I think they mean 'terrace' though I can't be absolutely sure. I've never seen Terrance there. I don't know anyone named Terrance.

The north point thing seems to be a small apology wandering aimlessly in a vast space because there was a space and to cap off the entire map the title and credit lines are in Comic Sans - that font that every map-maker loves to hate. Is this a subtle bit of carto-trolling? Could be. Could just be a pointless use of Comic Sans that makes no sense on a map that otherwise uses Arial. And why on earth would set the title in horizontal letters aligned vertically? Use Comic Sans with purpose. Reserve it for the uses it was designed for (children, comics and, latterly, to support those with dyslexia). It has no place on an information map like this - in the same way Papyrus has no place on restaurant menus.

So...what to do. Well, I've had a moan. I've justified my thoughts based on what I know about cartography. I tell you what, I'll make another version (for free) and offer it to the City of Redlands Parks Division. I'll post back when it's done and invite anyone and everyone to critique my map. In the meantime, you'll find me at Caroline Park where I hope they're not planning to update the current map with a similarly weak replacement.

Too much rain for a rainbow

National Weather Service today updated its rainbow colour scheme because of the unprecedented deluge caused by Hurricane Harvey in Texas.

#Harvey in perspective. So much rain has fallen, we've had to update the color charts on our graphics in order to effectively map it. pic.twitter.com/Su7x2K1uuz

— NWS (@NWS) August 28, 2017

Bravo for NWS in modifying its cartographic approach given a change in the phenomena it's mapping. Except they didn't do a very good job.

Old:

New:

The previous classification had 13 classes. the new one simply adds two more at the top end to deal with larger rain totals. In fact, all they've done is added detail to the 'greater than 15 inches' class and sub-divided it into three classes '15-20', '20-30' and 'greater than 30'. It'd be pedantic of me to note they still have overlapping classes (they do) but the bigger problem is they retained the same rainbow colour scheme and then added two more colours...a brighter indigo and then a pale pink.

Does that light pink area in the new map above look more to you? Or perhaps a haven of relative stillness and tranquility amongst the utter chaos of the disaster?  Yes, the colours are nested and so we can induce increases and decreases simply through the natural pattern - but the light pink could just as easily be seen as a nested low set of values than the more it is supposed to represent.

For a colour scheme that is trying to convey magnitude...more rain...more more more, you need a scheme that people perceive as more, more, more too. Different hues do not, perceptually, do that. Light pink does not suggest hideous amounts of rain compared to the dark purples it is supposed to extend.

We see light as less and dark as more. Going through a rainbow scheme where lightness changes throughout (the mid light yellow at '1.5-2.0' inches is a particular problem) isn't an effective method. Simply adding colours to the end of an already poor colour scheme and then making the class representing the largest magnitude the very lightest colour is weak symbology. But then , they've already used all the colours of the rainbow so they're out of options!

The very least they should have done is re-calibrated the classes to make the largest class encompass the new, out-of-all-known-range range. You can't simply add more classes when you're already maxed-out of options for effective symbolisation.

Better still, look around and learn how it should be done. The Washington Post has made a terrific map using a colour scheme that does have a subtle hue shift but whose main perceptual feature is the shift in lightness values. So we see more, more more as the colour scheme gets darker. It's simple. it really is.

The scientific community continues to use poor colour schemes and poor cartography to communicate to the general public. At least the mainstream media is doing a much better job.

[Update 29.8.2017 to include the New York Times piece]

New York Times today published one of the best maps I have seen in a long while. I mean 'best maps' of anything, not just the continuing deluge in Texas. Its simplicity belies its complexity and that's the trick with good cartography. Here's a pretty lo-res grab but go to the site and take a look.

They've got the colours spot on, A slight hue shift to emphasize light to dark but cleverly hooking into the way in which we 'see' deeper water as darker blue. Of course, it isn't really deeper blue but the way light is reflected, refracted and absorbed by water gives us that illusion. So, it acts as a visual anchor that we can relate to.

There's other symbology too - small gridded proportional circles that show the heaviest rainfall in each hour. The map is an animation so this gives a terrific sense of the pulsing nature of the movement of successive waves of rain (literally, waves!). The colours morph towards the higher end as the animation plays to build a cumulative total. This also has the effect of countering the natural change blindness we see when we're trying to recall the proportional symbols.

The two symbols work in harmony. And then, for those who want detail a hover gets you a graph showing the per hour total over the last few days.

These aren't the only maps in the NYT piece. The article is full of them. Each one carefully designed to explore a specific aspect of the disaster: the history of storms, reports, evacuations etc.

It's maps like those from The Washington Post and New York Times that prove that good cartography does exist and it matters. We really don't deserve the sort of maps that NWS pumps out. They're just really awful to look at, fail on a cognitive level and prove they haven't the first clue about how to effectively communicate their own science and data.

The irony is that the NYT map uses the NWS data of the rainfall data to make their own version and prove that it's perfectly possible to make terrific maps that communicate and which once again give us more reasons to #endtherainbow. Well played.

#endtherainbow

Map Mediocrity

I often get accused of holding maps and map makers to too high a standard. I can live with that. The people who make such accusations generally demonstrate low cartographic standards and tend to use them as an excuse for their lack of taste in cartographic decency or the standard of their own maps. It's a very easy accusation for people to make to justify their own lack of standards.

In a few weeks I'm presenting at the Society of Cartographers/British Cartographic Society Maps for Changing Reality conference in Durham in the UK and then, a short time after, the TOSCA 25th anniversary celebration conference on Enlightening Maps in Oxford. Both talks are loosely based on the idea of fake maps so I've been mulling over this idea of map mediocrity and why it is that there's a general malaise. Sure, we see some terrific maps but where are our standard bearers? What are we comparing maps to and what is the baseline of quality that we should seek?

I spent some time recently leafing through some beautiful maps from the 1950s and 1960s. Maps made over half a century ago by people who had nothing more than pens, rulers, scribecoat and so on. Now, granted, the collection is obviously heavily slanted towards a set of high quality work so there weren't many duds but my word, the maps were just simply beautiful. They were intricate, clear, made with a meticulous eye for detail and just superb works of art. This isn't to say fake maps never existed. They did and they came in many guises. And I'm not trying to yearn for a glorious golden age of cartography to resurface. What I hope to do is persuade people that we can up our modern game by simply taking on board some of the ethos of our cartographers of yesteryear or, at the very least, properly promote true quality in both maps and the cartographers that make them in our contemporary mapping landscape.

So many modern maps are fêted and held up as 'great maps' or they go viral or they're liked a gazzilion times but compare them to maps made 50+ yrs ago by likes of Hal Shelton and you'll see them for what they are. They are mediocre at best. People's general standards are at an all time low and despite many attempts to improve people's level of expectation it seems to be against a huge tidal swell of populist, pointless and poorly made maps.

Part of the presentation in Durham will be Steve Chilton and I sharing our list of #cartofail maps ahead of the 2017 Society of Cartographer's Gromit award. And there's dozens of contenders. This will be the fourth or fifth annual award. It doesn't matter much - it's just a bit of fun really; but there is an important subtext. The need to change people's expectations and reset them to something better has to take hold at some point else we'll forever be looking at rainbow colour scales, incorrectly projected data, non-normalized choropleths, glitzy animations (and sometimes all of these on one map!) and, worse, people constantly saying how a particular map is great, or trending, as if that actually matters.

What matters is that these people who clearly don't know the difference between a good and bad map need to stop. They need to give up the rhetoric, stop trying to sell shit and spend a little more time being considerate about cartography. Not every map is made equally. We should reserve our praise for those maps that really do offer something both functionally and visually. We should help people learn the difference and if they don't want to then they should be politely be invited to go find something else to comment on.

Mediocrity breeds mediocrity. It should embarrass people that their map, made with modern tech that supports so much gets nowhere near what someone with a pen could do decades ago. Yet it so often doesn't. I know people who brazenly showcase maps and talk about them as if they are something genuinely new, innovative, creative and beautiful when they are anything but. The sadness is they likely aren't aware they don't know the difference. I've tried talking to some of these types of people but it's intriguing that the old accusation of holding too high a standard resurfaces. It seems that the idea that if you say it, it must be true, is the only mantra they believe because these sort of people don't care anyway. But if we held maps to a higher standard and had more quality with which to challenge their mediocrity they would eventually have to step up or move on.

We live in an era where a lack of thinking, awareness and time spent on map design is accepted. Study old maps. Explore the craft. See how modern gems evidence lineage and show a development in the craft. As Bruce Lee said "Absorb what is useful. Discard what is not. Add what is uniquely your own". But to be able to make a decent map you must first know a little about what makes one and, importantly, what makes a poor one.

Far too many people just make noise with their daily claims of another 'great map'. Hold it up to scrutiny. Hold them up to scrutiny. Beware hyperbole and don't give mediocrity a place in the cartographic canon.

I don't have particularly high standards. But I do compare work across the ages and wonder how we became satisfied with mediocrity. I simply think if a job is worth doing it's worth doing right and that's really what I hold my own work accountable to. Mediocrity leads to fake maps or, put another way, a load of maps that ought to be considered fakes. They are dressed up but they all too often mislead the innocent.

We should be making maps that are so much better. A few are. Far too many fool themselves with their own acceptance of mediocrity and they consequently translate that to their readers. We can all do better.

I'll be talking about this at #mapreality & #TOSCA25. Don't forget to share your examples for the 2017 #Gromit award by tweeting your favourite #cartofail maps to either me @kennethfield or Steve Chilton @steev8. If you're coming to either event then bring something to wipe that eye - you'll either be laughing or crying or both!

Warp Factor Eleven

The UK Onshore Geophysical Library's William Smith - Interactive has wound me up.  It represents a cartofail that's extremely common.

William Smith produced his classic and beautiful maps of the Geology of England and Wales in the early 1800s. They are stunning. making them available digitally is also wonderful but...and this drives me nuts - why oh why, time and time again do we see people scan these wonderful old maps and then warp them to Web Mercator?

There's a reason Smith chose the right projection for his maps....because it was the right projection.

Would it not be easier to just change the projection of the web map service you're using and then allow the maps to be seen as intended? Instead we get the maps stretched and distorted. Horizontal text also becomes stretched and sits on a curve. It looks absurd.

200 years ago Smith made his map right. The very least we can do is honour it by using modern technology to re-present his work properly, not turn the warp factor up to eleven.

What's the point?

Campaign group 38 degrees have produced a map of the NHS crisis in the UK that purports to show the location of signatories to a petition demanding improved resources for the NHS.

Click here to put in your own UK postcode and here if you want to just see the map I've screen grabbed below
.

Each signatory is shown with a lovely blue Google map pin (zoom out to get the full 'death by map pin' effect just for kicks). Here's the cartography bit: "To protect anonymity, we randomly assign locations in the constituency for each signature. No real locations are shown."

Say what?

So you take data, you ignore location other than it exists within a certain boundary, you give it a false location and then put it on a map. Let's just zoom in a bit...

There you go. Mr Gordon Bennett in that lovely house round the corner signed the petition. Except he didn't, did he, because this is a randomly placed marker. Someone in the area whose postcode cannot define a particular property has had their data pinned to Mr Bennett's house. I suspect that pisses them both off.

This sort of map tells this huge lie while at the same time purporting a level of precision that assigns the unreality to very particular houses on the map.  It's a verson of the ecological fallacy in the interpretation of statistical data where  inferences about the nature of individuals are deduced from inference for the group to which those individuals belong. In this case precise location...albeit randomly assigned.

If you're going to randomize the data for display (a good thing) then aggregate it into a choropleth (you clearly have the boundaries which you're using to demarcate the selection) or show the postcode totals as a proportional symbol or do anything other than use point markers that make no sense and, worse, impute nonsense. Total cartojunk that obfuscates the real message. Put the damn numbers on the map. Make them big. Make those crucial messages the visual.

ht @StevenFeldman

Dangerous times. Dangerous maps.

A map showing the distribution of people on Trump's foreign banned nationals Executive Order appeared recently.

Map shows location of foreign-born people from 7 banned countries + elected official contact info https://t.co/uOCkECQI9Z #executiveorders pic.twitter.com/TKYzMLeNOI

— Azavea (@azavea) January 31, 2017

You can read the full blog post by the publishers here but here's a screen grab in case the tweet is taken down:

There's a few things that upset me about this map.

Firstly it's non-normalized. It shows totals. Choropleths need a rate or ratio. It was pointed out to me that the map uses Congressional Districts as boundaries and that means the populations are 'roughly' the same so it's all ok.

I'm afraid 'roughly' doesn't cut it. Each Congressional District represents about 711,000 people but you'll notice it's also split by state boundaries so, in fact, it's the data per state that's reapportioned into roughly equally populated areas. That'd be fine for mapping if you discounted Montana, Wyoming, North and South Dakota which encompass one Congressional District each. But they have populations of 1 million, 584,000, 740,000 and 853,000 respectively. None of these population totals can be easily split further without resulting in numbers even further away from 711,000 but it means the map of totals fails to respect these differences. This means the visual message is warped when you're trying to compare across the map. The primary function of the choropleth is to support visual comparison and unless you accommodate the underlying discrepancy in populations it doesn't.

The problem is exacerbated because those States are very large anyway so they inevitably dominate the map. Also, because the map uses the inappropriate Web Mercator projection those northern states are enlarged in relation to the rest of the country too - a further warping that our brains won't adjust for in deciphering the map's message.

There's plenty of other techniques that the map's maker could have used - cartograms, proportional symbols, dot density, hex-binning and so on. Each have benefits and each have drawbacks. The authors said they "wanted to stick with the district boundaries so people could see which district they reside in". So they chose to go with geography so people have less of a barrier to understanding the map. Fine - but the consequence of that decision is you have to be prepared to deal with the inherent cognitive bias and work hard to mitigate it properly.

Even if you think I'm being too nerdy about the issue of totals on choropleths (I'm not) then think about it this way...the map suggests around 3,400 as the bottom value of the highest class in the legend per Congressional District that's a lot of people right? Three and a half thousand of them.  As a percentage? Less than 0.5% and, frankly, that doesn't make the map nearly as persuasive.  Dig a little further:

So the upper class actually goes from 3,400 to 51,652.  And look at how tiny that little place is in downtown Los Angeles. 51,652 people all crammed into Congressional District CA-28 which you can hardly see, compared to 1,620 in North Dakota which you can really, really see. The choropleth doesn't help at all here. A different technique altogether would help. But even at 51,652 that's only 7% of the population. Still not exactly a huge proportion.

The data is also a little misleading. Libya cannot be extracted as a separate country from the American Community Survey used as a source for the map so the 'Other North Africa' designation was used - meaning people not on the banned list are included in the map. How many? Hard to know.

And reds? Hey, this is a sensitive issue. I mean a really f*cking sensitive issue. Red is not the colour to use because it's value-laden. We process it in a particular way and it means 'danger'. If the map is supposed to be an impartial display of the data then red is not the colour to use.

Finally, a friend of mine noted to me that they were concerned that the map even existed given it shows WHERE people on the banned list live. Popups even provide broken down summaries by country.  I countered by suggesting that at Congressional District level there's enough generalization to mask real locations but I take the point and it raises an ethical issue for cartography. In a time of unpresidented [sic] political turmoil, is it morally OK to publish this sort of map just because you can easily scrape the data? What purpose does it support? Given the general outrage that the ban on entry from nationals of 7 countries is tantamount to a partial ban on Muslims then the map could easily incite or inflame the situation further. If the intent is to be impartial then you have to be ridiculously careful to ensure you do just that and this map doesn't. Unless you are setting out to be explicitly persuasive or even propagandist, cartographers and map-makers have a responsibility to make maps that are not misleading and when dealing with sensitive subject matter it becomes crucial.

I am absolutely sure that the map-makers here actually had the opposite intention because they include contact details for Congressional Representatives - presumably as a call to action to encourage people to call in their opposition to the ban. Trouble is, for every one that might go to that effort there will be many more that look at a sea of red and interpret it differently. That's the power of maps.

As it stands the map is dangerous. It shows where people live that are currently on a banned list and that serves no purpose. It uses a good technique but poorly which is nothing more than creating visual alternative facts. It uses the wrong projection which exacerbates the problem. It uses slightly dubious data and, certainly, a bad choice of colours. I'd ban this sort of mapping. Period.

The NYT election map

It's election time in the US. It has been for well over a year (which is madness in itself) but we're down to the wire now with only a week to go before polling in what must be one of the most hate-fueled, vitriolic contests ever. Lies and misinformation have taken centre-stage but the sad truth is there are people (people who vote) who are easily taken in by lies and misinformation. They are sold it as a version of the 'truth' they can relate to and in which they wholeheartedly believe. And so that's how propaganda becomes reality and how candidates gain disciples. It's often the same with maps because they too sell a version of the truth.

We're arguably on the cusp of something far more important than worrying about a map in a newspaper but to my mind, at least, today's HUGE map in the New York Times warrants some cartonerd attention.

In today's print NYT: the most detailed election map we've ever printed: 30,000+ zip codes across a 4-page spread. pic.twitter.com/yjUHNSEvU2

— NYT Graphics (@nytgraphics) November 1, 2016

It is a truly magnificent piece of work. Large format. Eye-catching. Detailed. The US is a big country so if you want to show 30,000+ zip codes you better make your map big. I am a huge admirer of the New York Times graphics team and their cartographic work but this map, I'm afraid, contributes to the misinformation that has become so toxic this election season. Let's not worry about the periphery because it's the main map that takes centre-stage. It's that image which is defining and the impression that people see.

So what do they see? RED...lots of red. Any map that attempts to summarise a sparsely populated data set into a surface that exhausts space will mislead. It's inevitable. And with the USA, with a very heterogenous population distribution and vast swathes of land with barely a single rattlesnake of voting age it's a problem that is accentuated. The map uses Zip Code Tabulation Areas instead of counties, voting precincts or other geographies. There are problems with how ZCTAs mis-shapes the view but, frankly, any arbitrary boundaries have the same problems - the Modifiable Areal Unit Problem - statistical (and ultimately visual) bias that results with how you aggregate data into areas. The geography is what it is...but rather than perpetuate visually incongruous issues it's beholden on map-makers to deal with it.

For the last few years in my day job I've given a workshop at the Esri International User Conference that takes a single dataset of the 2012 election results and explores a range of about 20 different ways to present the very same data - each of which tells a very different story. Some of the maps can clearly be used to portray a particular dimension of the result and some can be used in deplorable ways (pun intended). Some reveal detail. Some mask it. Some show red. Some blue. You can see the full range of maps here if you're interested. The point of the session is to open people's eyes to the inherent biases that maps contain. What surprises me year on year is that an audience of people heavily invested in geo are equally surprised at the problems we explore. I guess it's to be expected - not every geo-expert is going to be a cartographic expert and they come to the session to learn and that's a great thing. But they are merely a small fraction of the population. The vast majority have no access to this sort of education. More than that - they have no idea they might even benefit from it or that there's a problem with how they read the maps they are served.

It's really a much bigger problem of geographical illiteracy and the lack of the basic need to view maps and graphics critically. With all these much larger issues it therefore becomes crucial for media organisations and those involved in communicating information to be cognisant of the limitations of the consumer. It's not really their fault - we're all born that way and we have a natural tendency to believe what we see, especially if it comes from a so-called reputable, impartial source. Maps should portray reality in a way that deals with the biases people inevitably see - to counter them rather than feed them. You only have to read the comments in reply to the NYT tweet to see how the map has been viewed and interpreted.

The problem with this New York Times map is the country itself which, admittedly, there isn't much they can do about but they could deal with the problem using different maps.  The size of the areas used to summarise the data are unequal. Some are therefore more visually prominent than others. Republicans hold on to large swathes of centrally located territory. Democrats get a shed-load of votes from the smaller, peripheral northeast. Additionally, they contain very different numbers of people so population density is unequal across the map - yet in terms of the symbology, each area is treated the same.

So you end up with large swathes of sparsely populated large areas in the mid-west being seen prominently and very small, densely populated areas on the coasts being seen much less prominently. The problem is compounded by two other factors - colour and focus. Red for republican is a colour that is seen more brightly than blue for Democrat. It is cognitively processed as 'more important'. Our eyes also naturally tend towards the centre of an image and a map on first inspection - so that's our initial focus. this all adds up to one massively misleading picture of the political geography of the USA. It screams REPUBLICAN which given Trump's persistent comments about the corrupt media is either an attempt for NYT to redress the balance or the Russians are to blame. And yellow for the marginal areas? I understand the desire for a neutral colour but in a generally two-horse race (mule, elephant, whatever) adding in other colours paints a different picture as well.

It can be different as these following maps of the 2012 election results, mapped by county, show. Using a value-by-alpha approach that overlays a layer of population density that is symbolised so that sparsely populated areas are more opaque will modify the image. It tunes out sparsely populated areas and brings a little focus to the areas with more people (more voters). All that deep red on the NYT version has now gone. Focus is shifted.

A cartogram does a similar job but by changing the shape of the areas - either warping them in relation to population density (e.g. a population equalising cartogram) or by giving each unit area the same shape (e.g. a hexagon grid). Yes, these are abstract and there's sometimes a challenge understanding the geography but they deal with the problems.

There's even the simple, yet effective, proportional symbol map that often gets overlooked. Symbol overlaps are often hard to reconcile but the symbol sizes do a good job of showing where there is more and where there is less as well as encoding the different colours.

Finally in this small selection of the myriad of alternatives, a dasymetric technique which uses a secondary layer of data into which you can reapportion the data can also show a more accurate distribution of information (e.g. dasymetric dot density) though, of course, any map of population data presented in this way will take on a similar appearance because, well, that's where people live!

Ultimately, there are dozens of different ways that the map can be made. None are 'right' and none are 'wrong' but they all tell different versions of the truth. This isn't cartographic pedantry. It's an important issue because it plays to people's views, opinions and search for the truth. My point here, is that maps can be extremely dangerous graphic tools. The NYT have, in my opinion, contributed to the misinformation that has enveloped this election by publishing this map in the form they chose. It presents a version of the truth that suits a particular view of reality. It is biased and dangerous. It's also too late because it's out there now and is simply just another piece of rhetoric people can use to support their own version of the facts.

By the way, I don't get to vote in the US election but I have lived and worked in the US for 5 years and call it home. Please...do yourselves a favour and go vote. You only have to look at what happened in the UK a few months ago where the vote was to leave Europe...a vote massively impacted because many people failed to turn out to vote who would otherwise have voted not to leave. You can't vote by liking or re-tweeting. Whatever the map says to you...just go and vote and help redraw the one you want.

UPDATE: Since writing this less than an hour ago the Washington Post has published a very well-timed piece entitled Election maps are telling you big lies about small things. They've been advocating cartograms based on one area per electoral college vote which I like. It retains a State-based appearance (which isn't as difficult to read as the population equalising versions) while doing a good job of presenting a visually balanced view of the data. I encourage you to read.

UPDATE 2: And now a good review of past approaches from NYT here. A rebuttal of the criticism they've faced? Maybe. They try and frame the big map as an attempt to look at the way physical geography impacts political patterns. That's a very nuanced way to explore the distribution of voting and I'd still argue that most who read the map will take away one message...more red = more Republican. Seven days out from the election is not the time to be playing with people's inherent perceptual and cognitive bias.