I would map 500 miles

When The Proclaimers released Sunshine on Leith in 1988 I was just about heading off to University (to study cartography and geography - that bit is important). They were not to my musical taste...why would I want to be beaten up for liking such a dreadful duo? Little did I know that over 25 years later I'd be making a map relating to one of their first and most celebrated ditties I'm gonna be (500 miles). If you want the background read on...if you want to see my map, scroll to the bottom.

The song is renowned for the lyric But I would walk 500 miles. And I would walk 500 more...blah de blah blah.... And so fast forward to 2014 and the following popped up in my twitter stream.

An attempt to answer @DragonXVI's fundamental question - Where the hell were the proclaimers actually walking to? pic.twitter.com/AYXs4IXTli
— Hazel McKendrick (@HazelMcKendrick) May 19, 2014

Now it's clearly tongue in cheek and fair play to Hazel McKendrick...I haven't seen anyone tackle this cultural dilemma before and she had a good go. Where, indeed, were The Proclaimers going to walk 500 miles to from Leith? And what about the 500 more? Unfortunately she used two perfect circles at the nominated distance around Leith but too late, another viral map is born and all the usual suspects begin clamoring to heap praise upon it.

I and a number of map-minded people folded our arms and began finding fault because the circles shouldn't be so, well...circular! Yet again someone had done something wrong on the internet (thanks to Barry Rowlingson for reminding me of the well observed XKCD cartoon).

Great idea. Nice bit of fun but...wait...the Web Mercator projection distorts shapes and areas pretty markedly. If you draw a line indicating 500 miles around Leith on that projection it would not be a circle.

Here's the classic example from The Economist on the threat from North Korean missiles that made the same mistake...

And here's the correction they were forced to publish after they had redrawn the lines properly and with respect to the projection used for the map...

Now it's questionable whether marking the range of North Korean missiles incorrectly is more or less dangerous than the lyrics from The Proclaimers (I guess it's a question of taste) but either way McKendrick's map is wrong. And then what about the fact that reaching Iceland would require them to walk on water? Now we're stretching the bounds of their talent just a little far with that one surely!

So, as a self-respecting cartonerd I re-did the map...

I still used Web Mercator and placed 500 mile and 1000 mile geodesic buffers around Leith (using the same huge assumption as McKendrick) to show the real distances as they appear on this map. These represent the theoretical extent of how far they might walk so if they went off-road and walked in a straight line that's where they would end up (notwithstanding the small matter of the wet stuff).

I also went a little further and used a bit on analytic acumen to calculate how far 500 miles would take them using the European road network. Then I calculated how far they could get by going 500 more. Those areas I show as shaded so we can see how far they would walk on land. I took some liberties...I presumed they only walked on roads and of course, they may know of sneaky short-cuts or go roaming cross-country. I also presumed the ferry journey's equated to a walking distance when they most likely sat down and had a rest (though if they walked round the deck then the eventual distances need reducing slightly)

It's not perfect (there's no North Sea ferries to Scandinavia and the Brittany ferry is also missing) but it's better than shoving circles on a Web Mercator projection and calling it cartography. The correct version applies knowledge of how maps work to make a sensible, correct map...even though the theme is distinctly daft and I still hate the song with a passion. I hate poor cartography more though.

That said, McKendrick's map has nearly 2,000 retweets at the time of writing. Mine? 88. Proof positive that actually nobody gives a shit about quality anymore...or when someone has gone to the effort of providing a correction they do their very best to ignore.

Update: Thank you to all the people who have read this since posted. And a particular thank you to all the other nerds out there who have found fault with my version. I have updated the map to make the necessary corrections and disclaimers.

Update 2: I couldn't resist...I did a Where the Streets Have No Name follow-up map...and I'm now thinking of all the other geo-related maps that can be made. I'm calling them Lyric Maps.

Update 3: Funny how frivolous work gets noticed...I've written an update in a new blog post called Pedantic cartography.

Spreading Light, Wasting Light

This blog entry is about mapping, honestly...but to get to my point I'll start with Dave Grohl and then get to Robert Downey Jr and Steven Feldman...bear with me.

On a recent flight I watched (for the second time) the great documentary on Sound City studios by Dave Grohl. The iconic music recording studio in Los Angeles was one of only a very few in the world to house a custom Neve 8028 24-track recording console designed by Rupert Neve. It was a hand-wired analog device which acted as the interface between the musician and the tape used to record the music but it was the console that gave the end product such a rich, unique sound. Often, musicians would need to play their track over 150 times to get it as they wanted it with all the imperfections ending up on the tape. They not only had to master their trade but be dedicated to giving their best live performance that would become the recorded piece. With only 24 tracks available on the console, the producers also had to be prudent and understand how a complete track was to be constructed to achieve their intended final sound.

The story is ultimately one of decline of Sound City as a viable business (it closed in 2011) despite it being the birthplace of countless classic albums produced in the late twentieth century as digital recording appeared and along with drum machines and other digital instruments, allowed people to record direct to a computer. The benefit's of digital recording are clear - the entry level for people making and recording music are massively decreased; the costs are much lower to make a recording; and anyone with a computer can record music. By using a program like Pro Tools you can play a track once then work on your computer to change duff notes, alter the pitch, add a range of effects (curiously with an image of an effects pedal you'll never likely have even seen in real life) and record as many tracks as you care. In short, it's making music for dummies and we've seen a proliferation of music appear as a result, all of it seeking perfection through a processed approach. You actually don't even need to be a musician to make an album these days. No craft, no art, no expertise as such...just working with digital data that equates to music when processed in a particular way.

However, as one contributor put it eloquently, there's nothing of the musician in much modern digitally produced music. A huge amount is over-produced with multiple layers of noise. What made music recorded through the Neve board at Sound City so immersive was the imperfections; the fact that you're listening to a real person play a real instrument with all minor imperfections in their playing exposed. It gave the music a 'feel' and a human quality that is difficult to express but which can be easily heard. It's an audible aesthetic and one that cannot be replicated in the same way using modern technology. The same commentator went on to say that yes, music recording has opened up like never before but he challenged us to consider whether it meant there was any better music out there. His thesis was simple..that all that has happened is more people with a lower level of ability or understanding of music (playing, recording, producing) now make music - but that there's a much higher proportion of poor music as a result. It's harder to find the quality any more because quantity sells.

Back to cartography - but as anyone who has read my blog before will realise, the above tale is pretty much verbatim my views on a lot of modern mapping. The death of expertise and massively reduced barriers to making maps has given us quantity but has seriously diluted the quality. People are becoming blinded to high quality mapping because they're consistently told to go look at this or that 'great' map by people who probably couldn't tell the difference anyway.

So my latest gripe is with the plethora of animated maps of social media data that are using CartoDB's torque engine. I like what CartoDB are doing and their torque engine is a very simple way to animate time-dependent data. But what of the result - how is it being used? Take a look at the following map of how Robert Downey Jr's twitter account gained followers in the first 24hrs after his first tweet:

And the man himself even commented on the map:

Just spreading light. RT @TwitterData This map shows what happened to @RobertDowneyJr followers after his first Tweet http://t.co/EhmewFyAdf
— Robert Downey Jr (@RobertDowneyJr) May 13, 2014

So what does the map show? I think Downey Jr was spot on...it just shows him spreading light. Actually, it doesn't really show anything at all, except for twitter's absence in China. So a huge global movie star gains followers in places where people live. Are we amazed? And I'll not even bother to go into the pitfalls of the problems of mapping and inferring anything from Twitter data (because I've done that before).

Here's another of the tweets that were posted around the recent F.A. Cup Final between Arsenal and Hull City: Again...it's just flashing light. What purpose does it actually serve? Visually, I like the effect but it really only shows us that people tweet. And therefore tweets reflect where people are on the planet. And Arsenal are much more popular than Hull City. And perhaps my good friend Steven Feldman is the one responsible for lighting up the UK as a twitter loving Arsenal fan?

There's just nothing particularly substantive about making maps like this. Once you've seen one you've seen them all. The digital tools make making the map very simple but it doesn't mean we're seeing good maps. It's quite literally a data dump on a map. There's no sorting, sifting, no trying to extract an interesting story or communicate a highlight (no pun intended though this would be a useful thing to do!). Light is cumulative and brighter = more but why are we so fascinated by 'more' of everything?

When I look at the map I see flashing light but after a short while I lose sight of the light area (most tweeting in relative terms..and really, the only metric this map is capable of displaying) because the almost strobe effect of the single tweets in the sparse areas becomes more prominent. Is this really the right message? And when the map is saturated with tweets what are we seeing? Anything?

I find the story of Sound City and its demise in the face of the onslaught from digital music has many parallels with my area of expertise. Whilst there's no doubt making maps these days is massively improved on many of the older techniques it doesn't necessarily equate to there being better maps. Like Grohl, who is a master of his craft (whether you like his music or not), many musical experts can still find ways to make their music and embrace digital technologies as part of their workflow. Trent Reznor is also a perfect example of this. A musician who knows his craft but is hugely experimental and who can weave modern technology into his work expertly.

I'm not decrying technological innovation and progress - just lamenting the decline of the thought that people used to have to put into making a map. If it was worth making it'd take time...and so that cost alone was a good way to decide if making the map was worth the investment. These sorts of maps can be made in minutes but without any sort of cartographic craft you end up making maps of flashing lights that tell us nothing or, as the title of Grohl's last Foo Fighters record stated...you're simply "Wasting Light'.

Update 1: there was an interesting side debate on this topic where some were suggesting that frivolous maps are nice once in a while. I agree. Firstly that this sort of animated map of social media data is content frivolous but also cartographically frivolous. It's experimental and at the moment we're in a period of cartographic change where for the first time in a long time technology is outpacing best practice. Experimentation is good and we need to figure out ways to harness these new approaches and to develop new best practices. This is a challenge and one that cartographers need to embrace. Unless they do, all we'll see is more of this type of mapping and more people telling more people how great it is.

The worm is turning

This entire blog is a conduit to encourage better mapping by exploring and providing critique on the dreadful, the mundane, the inaccurate and the sheer bloody hideous maps that we sometimes see. It's about standing up for what's right in my area of professional expertise and trying to reassert the value of high quality cartography (even if it hacks a few people off...which it seems to regularly).

For a few years, the over 100 blog posts I've written have sought to explain why bad maps are bad and how they might be far more effective...but over that same period there's also been a dramatic increase in the proportion of poor maps and, more than that, a massive increase in the various media sites that regurgitate, promote and peddle cartocrap and which also contribute through their own less than optimal efforts.

But maybe the tide is turning? This week has seen two media sites post articles on the problems with online maps....that's right...the PROBLEMS with online maps. Music to my ears.

First, Ben Blatt at Slate wrote an article entitled "Bad latitude: The trouble with viral maps". Then Business Insider's Mike Nudelman and Christina Sturbenz got in on the act with "The internet is obsessed with maps - here's why it's gone too far". And what prompted all of this? Ironically, it may well be the NBC Nightly News map that caused me such ire I wrote my "Changing face of America" blog post which was then itself used as a basis for the article by John Brownlee in his FastCoDesign blog "The worst infographic of 2014 (so far)".

The Changing face of America cartofail was perhaps so awful it may well have jolted people to question what they see a little more; to not be so accepting of every map they see and promote to such huge levels of viral contagion. Maybe, just maybe, some have actually pondered why people like me get so worked up at what all too often appears to be the dumbing down of the art and science of making maps? Or maybe online media has just measured the pulse of horror over this particular graphic and this week we're seeing some sort of reaction.

There's probably something else going on...we're possibly just reaching a tipping point. Our social media feeds are absolutely saturated with maps. Really saturated. Just yesterday I saw these two awful efforts:

The first was actually from a 2011 article in The Atlantic by Richard Florida entitled "Mapping the anti-creative class" that I hadn't seen before (but in social media if something goes around once it inevitably goes round again and again). It's just an abomination. There's no cartographic control been applied at all. It's a load of map-like components dumped on a page. There's no thought to symbolisation, layout or meaning. But it wasn't the map that horrified me so much as the write up which began "Those terrific cartographers over at...". No...NO. This is not cartography. It's been made by someone who clearly shows no cartographic acumen. The reporter clearly has no background in assessing or justifying that comment. It's tantamount to libel to accuse the author of cartography.

The second is from an article entitled "This is what America would look like without gerrymandering" in Vox by Andrew Prokop. It offers a really odd (and methodologically questionable) way of redistricting the United States that is based on using an algorithm that splits a state in half using the shortest possible line...which they kept repeating until they had roughly the same number of districts as the 'real' map. They are pretty shapes but also pretty meaningless. By repeating the flawed approach they simply propagate the errors at finer resolutions.

All of these media sites have been guilty of promoting this sort of stuff. They scrape and aggregate then push it to the unassuming and the uninitiated. In a tiny corner of the world people like me voice our concerns but it's a hard fight against large, loud, noisy voices, likes, pluses and retweets. But what happens when the media get bored of writing the same articles? They tend to take the opposing view. It's a cyclic approach to reportage...it's how so much of news media works. They build something up then knock it down again because then they have something new to write. The 15 minutes of fame that people have yearned for by creating maps they simply want to go viral may just be about to end because the backlash is beginning.

There's something ironic about Slate and Business Insider beginning to take a different stand since they have been two of those media outlets more than happy to promote cartocrap in the recent past. I'm not going to quibble though - if they bring this message to more people who then take a more critical eye to their consumption of online maps then that is a good thing. They will hopefully start to become a little more discerning, more demanding. Up to this point, the media have stoked the production of awful maps because they've been behind their promotion. If they begin to take a different approach then maybe people will also begin to think more...to produce work of a higher quality with at least basic construction being applied sensibly.

Maybe I'm being a little altruistic. I don't for one minute expect a dramatic shift from quantity to quality. As someone who has, in a very small way, campaigned for better mapping across all facets of my professional and private work in cartography it's a shift I hope has begun. It's a huge ship to turn and there's always people who believe their own facts but maybe if the outlets they rely on to push their work change tack, they may have to revisit their own approach.

Hubble bubble, transparency and trouble

I recently wrote a blog highlighting the problems of using transparency on choropleth maps when they overlay basemaps. Mike Bostock's recently posted "Let's make a bubble map" provided a really great tutorial on thematic mapping but also highlighted the issue of transparency once again. Here's his final map:

Look nice? Well yes, at first glance it does. It's clean, modern and pleasing to look at...and remember, these days most people are only glancing at maps so that first visual impression is oh so important. It's not just about looks, it's about the message we see with our eyes and how our brains are interpreting it. The use of transparency on this map creates a confused message because at first glance do you see size as important or darker colours as important? Or both?

There's a trend in online mapping in particular that uses transparency as part of the symbology design at every available opportunity. Modifying the alpha channel can be extremely useful and gives us a huge amount of flexibility to design symbols that work, particularly given the interplay of often complex symbology that competes for space.  It also allows us to produce some really pleasing effects. The problem here, though, is that applying transparency at an individual symbol level means that where symbols overlap you get darker colours. That's not a desirable effect when we're trying to communicate something about a quantity represented by a variably sized symbol...because it communicates something extra that is meaningless.

A proportional symbol is really just a geometric shape that reflects the value of a point or of an area (represented by a point). The overlaps have no spatial meaning whatsoever. Cognitively, we begin to confuse out estimation of magnitude (by seeing size differences) with another estimation of magnitude (lightness or saturation of colour). The use of transparency here creates a pseudo-choropleth effect that demarcates areas of circles as different to one another in some quantifiable sense. It's like seeing a load of stacked Venn diagrams where the overlaps have some additive property we should be mindful of. Except overlaps on proportional symbols are merely a function of proximity of the locations as well as choices made about relative symbol size. Overlaps do not mark out special areas where 'more' of something exists.

It's a confusing visual message. Additionally, where we see a large number of smaller symbols overlapping a larger one, the overlapped transparency masks the larger (more important) symbol. Look at the difference between the areas around Los Angeles County CA and then Cook County IL. How many of us miss the large symbol near Cook County because of the overlapping smaller ones? - yet it is similar in size to LA County, which just doesn't have as many counties nearby so doesn't get swamped. The overlaps are far more prominent on the east coast than the west simply due to the geography of there being more counties...but the increased density that we perceive through overlapping symbols causes an additive colour effect overplay the actual data magnitudes. By using transparency we're adding visual heirarchy to the symbols that show smaller darker ones as more prominent. That's at odds with a map like this where larger sizes should be at least on the same visual level.

Bostock correctly reorganises his symbols so smaller sit on top of larger. Then, instead of using transparency there are two more useful ways in which overlaps are dealt with to avoid the problems caused by transparency. First, the use of a border the colour of the background of the map is sufficient to demarcate symbols by effectively using cut-out effects. The symbols remain on the same visual level so we simply see the relationship between size and value. Like this:

Alternatively, hollow symbols with a strong outline might be used. Again, this makes the symbols all sit on the same visual level so we see size of the symbol as the visual variable relaying the information. For this example, the sheer number of symbols may not make this as good an approach but it can be used to good effect in different circumstances depending on the relationship of the geography, data and symbol scaling employed:

Bostock does a lot of other good work in the tutorial, not least pointing out the benefit of a decluttered basemap, or that we may consider using population weighted centroids as well as the need for strong visual anchors in the legend. All solid advice. The final version of his map as a web map adds a hover tooltip and also highlights the county by changing the border to black - a very sensible approach to give clarity to what is selected and to use interactivity in a useful way.

While I'm writing this though...there's one other niggle I have...the name: bubble map.

The long-standing term used to describe this type of map is a proportional symbol map. Now before someone calls me out on this and points to the fact Bostock notes this clearly at the start and end of the blog well yes, he does (he also refers to it as a graduated symbol map which isn't quite the same). So why persist in pushing a new term when a perfectly good one already exists?

Charles de Fourcroy is arguably the first to use proportional symbols in a graphic to show demographic data (he used squares...in 1782). We had to wait until 1837 to see proportional width symbols used for flow maps (Henry Harness). It was probably Charles Minard who then used the technique of making a symbol proportional to a value as part of his differently sized pie charts to show the origin of meats consumed in Paris...in 1851. And map-makers have been making (and calling them) proportional symbol maps ever since.
I appreciate Bostock probably wasn't the first to coin the phrase so it's unfair to pick on this example but it's symptomatic of a growing epidemic. Bubble charts are not new. They're proportional symbol maps. How much more perfectly decent cartographic history and relevant terminology is going to be reinvented? The connotation with the word bubble is that the symbols are circles. It's true that most proportional symbol maps use circles because they are often the most suitable (as in 'the perfect shape'). But here's a version with squares:

OK, I'd agree it's not as pleasing for this dataset but it can have its uses. If and when you use squares, hexagons or any other proportionally scaled symbol to map thematic data do we have do call them bubble maps too...or maybe each map sub-type now gets its own name...squarey map?

Anyway, I digress.

Transparency is your friend as a map-maker, but knowing when not to use it is as important as knowing when it can really help your work.