GOV.UK and Maps

Posts have been thin on the ground recently because I've been busy teaching a new course at the Uni.  However, its all over bar the exam marking now so I'm hoping to be more active here.

A friend has been involved in putting together GOV.UK - a site that provides the public with information from the British Government and acts as a clearing house to councils and other public bodies.  I really like the site, one of the key characteristics is that the designers have clearly focussed on user's needs.  I've had a quick whizz around looking for ways maps are, or could be, implemented in the site and a few thoughts spring to mind:

One Map, Many Points:   In the neighborhood section of the map you can enter your postcode and find services around you.  The site delivers you a list of possible local services, in the example below, we're looking at computer training courses:

As you can see, you get an individual map for each location.  It would be much better to provide one map with all the suggested services as markers with a linked list to the left of the screen (much as Google Maps and other services already deliver search results) with your entered post code shown as well.  This would enable the user to see which service is closer or if its close to their work commute route.

A nice add on to this would be travel time estimation circles centered on the entered postcode as found on TFL's 'Why not Walk It' maps.

Map Wiki: I also noticed that the site doesn't link users to useful map wiki or VGI (Volunteered Geographic Information) web sites such as FixMyStreet.  This enables the public to easily alert councils in the UK to problems with public spaces such as fly tipping or potholes because they interface with a map which is much easier than filling in a form.  I suspect that the remit for gov.uk limits their ability to have done this since they link out to councils sites for this sort of service and councils may or may not have chosen to use a site like FixMyStreet.  

Map as Spine:  The way GOV.UK is organized is centered around search and text based categories.  There's nothing wrong with this structure, I'm sure its what most people want to use.  However, I wonder if a map based structuring would add value as an extra way of organizing the data?  Instead of entering the site wondering how to answer a specific question, maybe people would like to mine the information to make broader decisions such as where in London would I like to move to?  A series of maps based on each area could be very useful showing people how well an area is serviced by the public sector and data from within the site could be used to populate the map.

Color Blindness and Color Blends

I came across these color blends in a post on the web today (to save blushes, I'm not linking) from a mapping developer.  Here's what they look like to the majority of us

and here's how 6% of the male population see it (via the excellent color oracle freeware)

clearly the bottom two blends will be very difficult for color blind users to interpret.

Color blindness is a lot more complex than I've explained here but generally blends from yellow to blue are much better than reds to greens.  More info on color blindness in maps here.

If you're interested in the more general uses of color in maps, the Haklay text book has a good couple of chapters.

Usability Problems with Zeros on Cluster Maps

Please excuse the lack of post recently, I've been particularly busy with teaching over the last month.

Some Experimental Results: My PhD student Craig has some results from a usability experiment on the UK Crime Maps site.  It's too early in the analysis to discuss in detail but one aspect is coming across very clearly: users are getting confused by the representation of postcodes with no crimes on cluster maps (explanation of cluster maps).

Problem:  When you zoom in on an area in the crime map, you are presented with a view as on the left.  The number of crimes in the last month is shown for each postcode as a number in a blob, e.g. for the postcode mid left (above Thurleigh Rd) there were 4 crimes.  The problem with this visualisation is that the boundaries of the postcodes aren't visible.  If you look on the right I've illustrated roughly where two of the postcodes are with dotted red lines.  The postcode on the left has 1 crime, the one on the right (Devereux Rd) has none and so hasn't got a blob at all.

When users were asked to pick out the postcode with the least crime on the actual crime map (left) they failed to understand that no blob = no crime and identified the blob with the lowest number as the postcode with the lowest crime.

Solution:  On collated point maps zero crime postcodes should be represented by blobs with zeros in them.  

Colour in Maps

On my other blog I've previously touched on the use of color in maps:

• Avoiding issues with color blindness
• Help picking color palettes (principally for thematic maps)
• The value of subtly colored base maps for map mashups
• The importance of choosing 'natural' colors for symbols (water = blue not red)

In researching my currently running course on communicating with web maps I came across some other best practices, mostly via the chapter on color in Muki Haklay's book.

Background = Blue:  We evolved doing things like picking berries from bushes in Africa, its therefore not surprising that the natural background color of that African landscape, the blue of the sky, is one as one that we still naturally associate with background.  Note how the red water above comes forward compared to the blue version and swamps out the map detail around it (map courtesy OSM)

Color Wheel Opposites:  The color wheel is a representation of 'color space' with hue around the edge. When choosing colors for symbols (such as placemarks) that need to visually stand out from each other, choose colors opposite each other on the color wheel.  A well used variation of this is yellow and blue.

Basemaps and Learning Curves

I'm up against the wall in terms of time still so short blog post today on a couple of topics both via James Fee.

Subtle Basemaps:  one of the basic problems with mashups has been putting data over a map designed for route planning.  Recently with Google maps API v3 and tools like tile mill people have started de-emphacizing background maps so that the data stands out better against the background map.  I agree with James that the OSM bright minimal style is a interesting development in this line of work.

I'd love to see some user test results to see how people fared working with a mashup based on this base map.

Learning Curves:  Also via James I read a great quote about teaching OS mapping software to students.

"One of the trepidations I have with teaching mapping courses using open source is that it usually requires some modicum of programming which is always way beyond the scope of any beginner class about making maps.  In addition, open source tends to favor linux or unix based tool chains that require config/make/make install tap dance before starting anything. This is akin to telling folks that they will need to forge their tools before they can start building a dog house."

Amen to that (emphasis mine).  I'm teaching web cartography at the moment mostly using Google Earth because I want them to learn about color, symbology and chart junk, not some abstract javascript that they will forget a week after the course is over.

The rest of the post goes on to explain why Sophia thinks TileMill for windows is a game changer.

Grids are good

Excuse the use of map inserts rather than screenshots, I haven't got much time at the moment.

Look at an old Ordnance survey map of the uk and you'll see it's covered by a thin, blue lined grid.  On recent map systems such as Google Maps and OSM there is no grid.  My discussion today argues that we should bring the grids back.

Grids No Longer Necessary?  To locate yourself on an old map such as OS a grid allowed you to use grid references.  Web maps produce points at the right place without such a grid so because a grid adds to the visual clutter of a map, we're best rid of them?

Nope.

Landmarks and Scale:  A grid is helpful because it gives a sense of scale to the map.  If you're looking at part of the antarctic


View Larger Map

 you have no sense of the size of what you're looking at.  Fix a grid of 1km spacing over the top and you can immediately judge distances.

Point Landmarks.  To locate yourself on a map your brain looks for known features and fixes your position in relation to this point.  Here in London that means that Londoners often describe an area in relation to underground (=metro) stations because that's how most of us get around.  The problem with this is that in tests it's found that people tend to position points that they remember by a landmark too close to the landmark.  So if my house was 1 mile away from Clapham South underground station if I was tested I'd tend to draw it closer, say 3/4 of a mile.

Line Landmarks Another way we locate points is in relation to line features such as a major road or coastline.  This has problems too.  Consider the question, which is further west of these UK cities: Glasgow or Cardiff?


View Larger Map

 Glasgow is towards top of map in Scotland.  Cardiff is due west of London and Bristol, you may have to zoom out or in a little 

Without looking at a map most Brits think that Cardiff is further west.  That's because they have a mental map in which the East coast of the UK runs north south whereas it actually runs NNW-SSE and they warp space to accomodate this misconception.

Grid Solution Because a grid runs exactly north-south and east-west it gets over the Glasgow-Cardiff problem.  Also, it minimises the underground station problem as it represents a continuous set of landmarks rather than discrete points (although this point is worthy of more testing to prove this is the case).  So a grid can deliver both a sense of scale and a landmark system which allows people to fix positions on a map and remember their positions correctly.

When to use Grids: I suspect that its more useful to use a grid in an area without a strong set of landmarks (desert, tundra) rather than somewhere with good landmarks, if you put a grid over US cities with their right angled street systems I imagine users would ignore the map grid because the street system provides such a good system of landmarks already.

National Rail into Google Maps in the UK

In an earlier post on web transit maps in London I noted that when you used the public transport route calculator on Google Maps it didn't include national rail.  That wasn't too much of a problem itself (it's obvious they were working on whatever licensing/data issues were holding up getting that data in) but my criticism was that the map didn't make that clear.

The discussion has now become academic as I learn via Ed Parsons that national rail trains are now included in their route planner.  Good work Google!