Wednesday 20 November 2013

GIS Day fun

It's GIS Day. What do you mean you've never heard of it? Well, in the spirit of contributing a little fun to those having a geotastic day here's a little nugget I used to get my students to do as a map interpretation exercise. I can't claim it's Oxford Polytechnic tutor Roger Anson made me do it during our cartography degree. So...get your pens and pencils out and let's see what you can conjure up. Submit your drawings (photos of scraps of paper, links to web maps or 3D animations with music) in the comments. I'll think up a prize for the most accurate answer...and if former Oxpoly carto grads are reading then you're excluded!

Draw, stating your scale, a contoured sketch map to show:

An island 65km long from SW to NE which varies in width from 48km in the SW to 16km in the NE.

The SW coast is much dissected by long, narrow fjord-like inlets, and is fringed by 5 small rocky islands of varying sizes. From this coast the land rises sharply to a plateau some 600m above sea level and extending through about one-third of the island.

The plateau descends to a low undulating plain about 25km long and 20km wide.  From the plain a range of hills rises to the NE and is flanked by a coastal plain about 8km wide. From these hills, rivers flow to both plains and also from the plateau to the larger plain.

The plateau is gritstone. The hills which run down to the coast in the NE, to form cliffs, are of chalk. Much of the smaller coastal plain is marsh, but the larger plain, from which two estuaries open, is of well drained land predominantly covered by alluvium.

In addition to relief and general topography, show drainage features, possible sites of settlement and lines of communication. Name your island appropriately!

Tuesday 12 November 2013

To react or not to react. That is the question.

It seems I've irked Mr MacWright again with my latest blog about the crime map.

He's even gone to the effort of cataloging my blogs and creating a taxonomy of alleged anti-MapBox sentiment:

A little scary but kudos for the effort! Odd classification though. I try not to focus on any platform but, rather, look at specific maps so using my blogs as an anti-MapBox metric is being a little mendacious.

This is a blog that voices constructive criticism about maps...that's the point. That's what the internet does - provide a place to share thoughts and ideas.  My intention in the blog is to challenge people's ideas of how maps work by pointing out their weaknesses. Not everyone will agree but it's my blog and I stand by the comments. When I can, or time/data permits, I even rework maps to show how I feel they may be improved. Choose not to read if they offend but making the assumption this conduit is my only voice is a serious misrepresentation.

I speak at many events. I write and publish. I perform numerous critiques in my role at work and these are forwarded to the appropriate persons using the appropriate form.  This blog allows me to explore publicly visible maps too. I could choose not to but there are already too many people who tacitly accept any map the internet pushes. This blog is but a fraction of my contribution to cartographic discourse, both positive and negative (though I prefer to see it as constructively pointing out limitations rather than just being negative for the sake of it). It's also true that silence often says much more than words so sometimes it's simply best not to use social media as a vehicle and choose a less public form of interaction instead.

My take on the maps I use as a basis for comment is to see how the message suffers through poor cartography. The same is true for the crime map blog which is very positive about the technology underpinning it but the message the map delivers is flawed.  I struggle to see how one might come to the conclusion it was negative about MapBox per se.

I don't criticize the work of my colleagues via my blog because I strongly suspect my employer would be somewhat displeased. I wouldn't imagine this is a situation unique to me. Internally, comments are shared. I am also very critical of my own maps where I cannot necessarily achieve what I might want. It's really up to others to provide critical commentary on my work (which I would encourage)...and they often do which is what helps in trying to improve my own work.

There are many ways to influence change in trying to improve how maps communicate and my blog is one piece of a much larger jigsaw. You have to see the whole puzzle to get the big picture. Take my tweets for instance...there's probably a fair split between sharing or commenting on good work as their is sub-par work. I've certainly been pretty positive in tweets over the last few months about many initiatives coming out of MapBox, CartoDB, d3, the open source community and a host of other stuff.  I was the author of a very popular blog on the Esri web site explaining how those using ArcGIS Online can consume their MapBox maps as an alternative to the Esri offerings.

Do good work. Share it. Take critical comment in the right spirit. Set up parody Twitter accounts. Use your right of reply if you want.

To react or not to react: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous tweeting,
Or to take arms against a sea of misrepresntation,
And by opposing end them? To blog: to tweet.

Monday 11 November 2013

Oh crikey!'s the rozzers!

Police.UK just published an updated crime map.

They've been hard at work over the last couple of years since the original version which was released in February 2011.

OSM. Check
MapBox.js. Check.
Leaflet. Check.
Dynamic cluster markers. Check.
Neat customisable search area. Check
Clean UI. Check

Yep, they've got all the latest tech driving the map and in respect of the UI/UX it's a clear improvement but has it improved in terms of what it offers the casual user?  I wrote a blog on the first map and pointed out a few cartographic issues with how the data was misrepresenting geography and what's changed?

Nothing. Check.

It's a new face on an old map. The data model is the same as before...crimes are aggregated to a generic locator placed on a road segment. Only when you click on the marker symbol do you get a breakdown of crime type (and only when you're zoomed well into the map). I can filter by type but that just updates the number.  Why hasn't the map been designed so I can easily 'see' the patterns? Why make me have to interpret numbers?

Why aren't the symbols scaled properly...look in the image above. 1 crime is the same sized symbol as 8. 286 only marginally larger. This is a false picture visually and perceptually. Did 286 crimes really get committed 'here' as it says when you open the popup? Of course they didn't. They occurred across an area. So what area is that and how can I see it? This is a perfect example of the Modifiable Areal Unit Problem at work. Every number in the map is a function of the size and shape of the reporting area. What are these? It's important to understand them to gauge how those arbitrary areas affect the pattern you're seeing. Small numbers appear on smaller roads and larger numbers on larger the reporting seems to have a relationship with the nearest road and of course you'd expect more crimes over longer roads covering larger areas.

And here's the sting...unless those numbers all relate to equally sized areas, or they are on an equally spaced grid the map is clearly falling foul of that age old problem of not normalizing your data to account for differently sized enumeration areas.  I have no problem with proportional symbols of totals being used as long as I can see what the pattern of the enumeration area is...but without it I have no idea how the map is being shaped whatever slick interface I have to navigate.

My previous comments about version 1 stand...the proportional symbols are weak and suggest absolute location as well as the uncertainty of the underlying enumeration geography not being visible. Why not use a proportional linear symbol for the entire road rather than suggest all crimes occur at that specific point? Better still...why not symbolize the reporting areas to give us a truer picture of crime across space? Are area maps just not sexy enough any more?

Is this a question of the data being generalized to a nearest point or is it the mapping trying to introduce some fuzziness so as not to be too accurate in identifying specific locations? Either way, the map locates crimes at points that don't actually locate crimes and probably fails to show us the true pattern. It's a dangerous story to tell. It's also laziness...the data are most likely reported to a nearest enumeration point and that defines the map. No attempt to process it into something more meaningful.

As readers of Treasure Island know full well, X didn't actually mark the spot where the treasure was buried...and this national map of crime perpetuates this myth by showing inaccurate locations. I look forward to version 3 in 2016 when they might actually address the data and cartographic issues of the map rather than just the cosmetic.The KISS principle used to mean "Keep It Simple Stupid" but now seems to be more appropriately "Keep It Slick Stupid".  UI/UX is not the same as cartographic design.