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Questioning Election Data to See if It Has a Story to Tell

I know, I know, the local elections are old news now, but elections come round again and again, which means building up a set of case examples of what we might be able to do – data wise – around elections in the future could be handy…

So here’s one example of a data-related question we might ask (where in this case by data I mean “information available in: a) electronic form, that b) can be represented in a structured way): are the candidates standing in different seats local to that ward/electoral division?. By “local”, I mean – can they vote in that ward by virtue of having a home address that lays within that ward?

Here’s what the original data for my own local council (the Isle of Wight council, a unitary authority) looked like – a multi-page PDF document collating the Notice of polls for each electoral division (archive copy):

IW council - notice of poll

Although it’s a PDF, the document is reasonably nicely structured for scraping (I’ll do a post on this over the next week or two) – you can find a Scraperwiki scraper here. I pull out three sorts of data – information about the polling stations (the table at the bottom of the page), information about the signatories (of which, more in a later post…;-), and information about the candidates, including the electoral division in which they were standing (the “ward” column) and a home address for them, as shown here:

scraperwiki candidates

So what might we be able to do with this information? Does the home address take us anywhere interesting? Maybe. If we can easily look up the electoral division the home addresses fall in, we have a handful of news story search opportunities: 1) to what extent are candidates – and election winners – “local”? 2) do any of the parties appear to favour standing in/out of ward candidates? 3) if candidates are standing out of their home ward, why? If we complement the data with information about the number of votes cast for each candidate, might we be able to find any patterns suggestive of a beneficial or detrimental effect living within, or outside of, the electoral division a candidate is standing in, and so on.

In this post, I’ll describe a way of having a conversation with the data using OpenRefine and Google Fusion Tables as a way of starting to explore some the stories we may be able to tell with, and around, the data. (Bruce Mcphereson/Excel Liberation blog has also posted an Excel version of the methods described in the post: Mashing up electoral data. Thanks, Bruce:-)

Let’s get the data into OpenRefine so we can start to work it. Scraperwiki provides a CSV output format for each scraper table, so we can get a URL for it that we can then use to pull the data into OpenRefine:

scraperwiki CSV export

In OpenRefine, we can Create a New Project and then import the data directly:

openrefine import from URL

The data is in comma separated CSV format, so let’s specify that:

import as csv comma separated

We can then name and create the project and we’re ready to start…

…but start what? If we want to find out if a candidate lives in ward or out of ward, we either need to know whether their address is in ward or out of ward, or we need to find out which ward their address is in and then see if it is the same as the one they are standing in.

Now it just so happens (:-) that MySociety run a service called MapIt that lets you submit a postcode and it tells you a whole host of things about what administrative areas that postcode is in, including (in this case) the unitary authority electoral division.

mapit postcode lookup

And what’s more, MapIt also makes the data available in a format that’s data ready for OpenRefine to be able to read at a web address (aka a URL) that we can construct from a postcode:

mapit json

Here’s an example of just such a web address: http://mapit.mysociety.org/postcode/PO36%200JT

Can you see the postcode in there? http://mapit.mysociety.org/postcode/PO36%200JT

The %20 is a character encoding for a space. In this case, we can also use a +.

So – to get information about the electoral division an address lays in, we need to get the postcode, construct a URL to pull down corresponding data from MapIt, and then figure out some way to get the electoral division name out of the data. But one step at a time, eh?!;-)

Hmmm…I wonder if postcode areas necessarily fall within electoral divisions? I can imagine (though it may be incorrect to do so!) a situation where a division boundary falls within a postcode area, so we need to be suspicious about the result, or at least bear in mind that an address falling near a division boundary may be wrongly classified. (I guess if we plot postcodes on a map, we could look to see how close to the boundary line they are, because we already know how to plot boundary lines.

To grab the postcode, a quick skim of the addresses suggests that they are written in a standard way – the postcode always seems to appear at the end of the string preceded by a comma. We can use this information to extract the postcode, by splitting the address at each comma into an ordered list of chunks, then picking the last item in the list. Because the postcode might be preceded by a space character, it’s often convenient for us to strip() any white space surrounding it.

What we want to do then is to create a new, derived column based on the address:

Add derived column

And we do this by creating a list of comma separated chunks from the address, picking the last one (by counting backwards from the end of the list), and then stripping off any whitespace/space characters that surround it:

grab a postcode

Here’s the result…

postcodes...

Having got the postcode, we can now generate a URL from it and then pull down the data from each URL:

col from URL

When constructing the web address, we need to remember to encode the postcode by escaping it so as not to break the URL:

get data from URL

The throttle value slows down the rate at which OpenRefine loads in data from the URLs. If we set it to 500 milliseconds, it will load one page every half a second.

When it’s loaded in all the data, we get a new column, filled with data from the MapIt service…

lots of data

We now need to parse this data (which is in a JSON format) to pull out the electoral division. There’s a bit of jiggery pokery required to do this, and I couldn’t work it out myself at first, but Stack Overflow came to the rescue:

that's handy...

We need to tweak that expression slightly by first grabbing the areas data from the full set of MapIt data. Here’s the expression I used:

filter(('[' + (value.parseJson()['areas'].replace( /"[0-9]+":/,""))[1,-1] + ']' ).parseJson(), v, v['type']=='UTE' )[0]['name']

to create a new column containing the electoral division:

parse out the electroal division

Now we can create another column, this time based on the new Electoral Division column, that compares the value against the corresponding original “ward” column value (i.e. the electoral division the candidate was standing in) and prints a message saying whether they were standing in ward or out:

inward or out

If we collapse down the spare columns, we get a clearer picture:

collapse...

Like this:

summary data

If we generate a text facet on the In/Out column, and increase the number of rows displayed, we can filter the results to show just the candidates who stood in their local electoral division (or conversely, those who stood outside it):

facet on inout

We can also start to get investigative, and ask some more questions of the data. For example, we could apply a text facet on the party/desc column to let us filter the results even more…

inout facet filter

Hmmm… were most of the Labour Party candidates standing outside their home division (and hence unable to vote for themselves?!)

Hmm.. labour out

There aren’t too many parties represented across the Island elections (a text facet on the desc/party description column should reveal them all), so it wouldn’t be too hard to treat the data as a source, get paper and pen in hand, and write down the in/out counts for each party describing the extent to which they fielded candidates who lived in the electoral divisions they were standing in (and as such, could vote for themselves!) versus those who lived “outside”. This data could reasonably be displayed using a staggered bar chart (the data collection and plotting are left as an exercise for the reader [See Bruce Mcphereson's Mashing up electoral data post for a stacked bar chart view.];-) Another possible questioning line is how do the different electoral divisions fare in terms of in-vs-out resident candidates. If we pull in affluence/poverty data, might it tell us anything about the likelihood of candidates living in area, or even tell us something about the likely socio-economic standing of the candidates?

One more thing we could try to do is to geocode the postcode of the address of the each candidate rather more exactly. A blog post by Ordnance Survey blogger John Goodwin (@gothwin) shows how we might do this (note: copying the code from John’s post won’t necessarily work; WordPress has a tendency to replace single quotes with all manner of exotic punctuation marks that f**k things up when you copy and paste them into froms for use in other contexts). When we “Add column by fetching URLs”, we should use something along the lines of the following:

'http://beta.data.ordnancesurvey.co.uk/datasets/code-point-open/apis/search?output=json&query=' + escape(value,'url')

os postcode lookup

The data, as imported from the Ordnance Survey, looks something like this:

o:sdata

As is the way of national services, the Ordnance Survey returns a data format that is all well and good but isn’t the one that mortals use. Many of my geo-recipes rely on latitude and longitude co-ordinates, but the call to the Ordnance Survey API returns Eastings and Northings.

Fortunately, Paul Bradshaw had come across this problem before (How to: Convert Easting/Northing into Lat/Long for an Interactive Map) and bludgeoned(?!;-) Stuart harrison/@pezholio, ex- of Lichfield Council, now of the Open Data Institute, to produce a pop-up service that returns lat/long co-ordinates in exchange for a Northing/Easting pair.

The service relies on URLs of the form http://www.uk-postcodes.com/eastingnorthing.php?easting=EASTING&northing=NORTHING, which we can construct from data returned from the Ordnance Survey API:

easting northing lat -long

Here’s what the returned lat/long data looks like:

lat-long json

We can then create a new column derived from this JSON data by parsing it as follows
parse latlong to lat

A similar trick can be used to generate a column containing just the longitude data.

We can then export a view over the data to a CSV file, or direct to Google Fusion tables.

postcode lat long export

With the data in Google Fusion Tables, we can let Fusion Tables know that the Postcode lat and Postcode long columns define a location:2222

Fusion table edit column

Specifically, we pick either the lat or the long column and use it to cast a two column latitude and longitude location type:

fusion table config cols to location type

We can inspect the location data using a more convenient “natural” view over it…

fusion table add map

By applying a filter, we can look to see where the candidates for a particular ward have declared their home address to be:

havenstreet candidates

(Note – it would be more useful to plot these markers over a boundary line defined region corresponding to the area covered by the corresponding electoral ward. I don’t think Fusion Table lets you do this directly (or if it does, I don’t know how to do it..!). This workaround – FusionTablesLayer Wizard – on merging outputs from Fusion Tables as separate layers on a Google Map is the closest I’ve found following a not very thorough search;-)

We can go back to the tabular view in Fusion Tables to run a filter to see who the candidates were in a particular electoral division, or we can go back to OpenRefine and run a filter (or a facet) on the ward column to see who the candidates were:

refine filter by division

Filtering on some of the other wards using local knowledge (i.e. using the filter to check/corroborate things I knew), I spotted a couple of missing markers. Going back to the OpenRefine view of the data, I ran a facetted view on the postcode to see if there were any “none-postcodes” there that would in turn break the Ordnance Survey postcode geocoding/lookup:

postcode missing...

Ah – oops… It seems we have a “data quality” issue, although albeit a minor one…

So, what do we learn from all this? One take away for me is that data is a source we can ask questions of. If we have a story or angle in mind, we can tune our questions to tease out corroborating facts (possbily! caveat emptor applies!) that might confirm, helpdevelop, or even cause us to rethink, the story we are working towards telling based on the support the data gives us.

Written by Tony Hirst

May 5, 2013 at 11:38 pm

9 Responses

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  1. Some very interesting stuff there, which leads to several questions. For instance, we know that MPs will relocate to their constituency (though usually only once elected unless it is a “safe” seat), so does this simply favour the encumbent? To what extent do candidates lie about their home address? I do have anecdotal evidence of this (using friend’s address or party offices). It would then be interesting to see under what circumstances local candidates are most common (serious challenger to the encumbent, no hopers etc). Finally, it would be great to see if there is any home advantage in the results.

    Tom Franklin

    May 6, 2013 at 7:36 am

    • @tom It’s worth bearing in mind that the example I am using is Isle of Wight local election data, where, if you live on the Island, you can’t live more than about 15 miles from anywhere else on it;-)

      Tony Hirst

      May 6, 2013 at 9:29 pm

  2. Tony,

    thanks for the great post. I’ve created a quick VBA automated mashup of this using your data and approach. http://excelramblings.blogspot.co.uk/2013/05/mashing-up-electoral-data-follow-on.html

    Bruce

    • @Bruce thanks for doing that. How long did it all take in the end? I find that the write up often takes longer than the actual hack! By the by, what sort of “Excel skill level” do you think folk: a) tend to have; b) would need in order to be able to copy your method; c) would need in order to be able to recreate the method in the way you did?

      Tony Hirst

      May 6, 2013 at 9:38 pm

      • Tony,

        I guess I got the coding & testing done in about an hour. I stopped there, leaving myself an hour for the write-up. If I had time I would have done some of the mapping stuff, but as you rightly say .. the write up consumed most of the remaining hour.

        So skill levels,
        a) I run a google group for people using my stuff and mainly the people that get as far as asking a question have pretty decent skills levels – enough to have a go at this stuff, and at least to know what questions to ask, and to be able to implement the solutions in live apps afterwards. There are some really smart VBA people out there – you see them answering really complex questions on forums, and by and large they are non-professional developers.. Just people who have come to find themselves at home with Excel & VBA – let’s call them Group A. The majority of VBA people though, tend to use it for automating what they do manually – by trying to do the same things in VBA as they do by hand – which is after all one of the main reasons for VBA. Let’s call them Group B.
        b) copying my method would be pretty straightforward, since it’s largely a mashup of existing libraries. Group A could and already do. However Group B often struggle with the concept of VBA being used for things that are not pure Excel automation.
        c) hmm… There’s a lot of code under the covers which has grown up over time. I would say that a large proportion of Group A could, but they would likely need to have had experience of a few other platforms and languages.

        Bruce

      • Tony,

        follow up – the Google Apps Script version – took about half hour to do this one, but its just a translation of the VBA version.

        http://ramblings.mcpher.com/Home/excelquirks/json/rest/scraperwiki/mashup

        Bruce

  3. “Hmmm…I wonder if postcode areas necessarily fall within electoral divisions? I can imagine (though it may be incorrect to do so!) a situation where a division boundary falls within a postcode area, so we need to be suspicious about the result, or at least bear in mind that an address falling near a division boundary may be wrongly classified. ”

    It’s not just wards which can be straddled by postcodes; it’s whole council areas. The Conservative who represents my ward in MK lives (or lived, she pledged to move if she won) in a house with a postcode which centred outside the Milton Keynes council boundary, which would have made her ineligible, not merely far-flung.

    Simon HB (@norock)

    May 6, 2013 at 11:33 am

    • Simon – which is where plotting things on a map helps, e.g. both the electoral division area and the postcode boundary area?

      Tony Hirst

      May 6, 2013 at 9:31 pm

  4. [...] Questioning Election Data to See if It Has a Story to Tell I started to explore various ways in which we could start to search for stories in a dataset [...]


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