Home > #MTBoS, Maths > It’s election time again

It’s election time again

It’s election time again, and we all know what that means….. BAD GRAPHS!!!! Last year, in the run up to the locals, we had some classics and this time is no different.

Let’s start with a positive, an example for others to look at:

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Amazing isn’t, despite the fact that he’s running for parliament, Jamie Hanley (@jamiehanley) – Labour candidate Pudsey, has managed to buck the trend and include a fully correct bar chart!! Dave Gale (@reflectivemaths) did point out that technically the claim “Can’t win here” is invalid, and should in fact read “statistically extremely unlikely to win here” or something similar. But that doesn’t take away from the excellent bar chart.

Now for some crimes:

Exhibit A

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These two came through my door, both from Greg Mulholland (@gregmulholland1) the Liberal Democrat defending the constituency. The first error, I’m sure you’ll notice, is that the numbers are different on both leaflets despite them claiming to be from the same set of election results! The second error is that the tiny gap between the Lib Dem and the Labour bars is supposed to signify around 700 people (on one, 800 on the other!) and that massive gap between the Labour and Conservative bars is supposed to be 1200 on the top and 1600 on the bottom. So the biggest it should be is twice the gap between Lib Dems and Labour, as you can see it is considerably more than this. The third error is that the aforementioned gaps between the Labour and the Conservative bars is supposed to signify between one third and one fifth of the total size of the Conservative bar, but as you can see it is actually considerably bigger on both bars. The final error is the one Dave mentioned above, the claim “Can’t win here” is technically wrong. If one of my pupils turned this in I’d be fuming!

Here’s what they should look like:

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Exhibit B

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This classic was sent to me the other day and is from a Liberal Democrat leaflet in Bristol West, where Stephen Williams is the candidate and is trying for reelection. This is a terrible example. Firstly, the gap between Lib Dems and Labour is, as the numbers state, 10% and the gap between Labour and conservative is 20%, so clearly the gap in the bars should reflect this and the Labour bar should be considerably nearer the Conservative bar. However, this is clearly not the case in this picture. Next, the gap between the Labour and Conservative bar should be less than half the size of the Conservative bar, it isn’t! And again, Dave will be screaming about that all too familiar slogan. Another terrible effort. Here’s what it should look like:

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Exhibit C

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This was sent to me by a friend, it’s from literature relating to the local elections that are currently being held and is from the Lib Dem candidate (Martin Hughes) in the Horsforth Ward of Leeds City Council. Error 1, as you can see, numbers wise the difference between Lib Dem votes and Conservative votes is 157 and the difference between Conservative votes and Labour votes is 216, these numbers are fairly similar, but the gap on the bar chart suggests the Tory Labour difference to be roughly 4 times that of the Lib Dem Tory difference. And 216 is very definitely not 4 times 157. Error 2: the 605 vote difference between Labour and UKIP is shown by a gap that is much bigger than the entire UKIP bar which represents 1059, a considerable amount of votes more! And again, there’s that slogan. Another terrible bar chart, and here’s the correct version:

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Exhibit D

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Greg again, it’s no wonder that Colin Beveridge (@icecolbeveridge) has started referring to this sort of graph as a “Mulholland”, every leaflet that comes has another crime against statistics contained in its midst, perhaps Greg should read Colin’s book? This one is particularly telling, firstly we have a question of validity, the data is ten years old. There has been a general election since then so why use 2005 data? It fits the narrative, the leaflet is aimed at trying to convince Conservative voters to vote tactically and the information from the last election would tell them that actually the Conservative candidate came second. As you can see above though, the landscape has changed and the aggregated results (whichever version is true!) in the last local do suggest a similar landscape to 2005. Why hasn’t he used those again? I can only conjecture that it is because he wanted to use percentages somehow as a general as turnout is much higher it seems closer? Secondly we have the fact that there is a 4% difference between Labour and Lib Dems and a 6% difference between Labour and Conservative, this should show as a similar difference in bar heights (the difference Labour to Conservative should be 1.5 times the Labour Lib Dem difference), as you can see the difference is nothing of the sort and 6% appears to be ten times the size of 4%. Then there’s the Tory bar, apparently representing 27% yet smaller in size than the aforementioned 6% gap. And to top it off, that slogan again! Here it is, but correct:

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Exhibit E

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Here we have a superb example of a terrible misleading bar chart. It’s from Liberal Democrat literature in Lewisham East (where the candidate is Julia Fletcher). As you can see from the graphic, the Labour bar is largest, followed by the Lib Dems who are fairly close then the tories who are much further behind. But hang on, look at those percentages! The Labour bar represents 43%, the Lib Dem bar 28% and the Conservative bar 23%, the Lib Dem bar should be much nearer the Conservative bar than the Labour bar! And both Lib Dem and Tory bars should be around half the size of the Labour one. And again we see that slogan. Another shocking effort, and here’s another correct version:

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Exhibit F

As I’ve been writing this post I’ve just received this link to this crime against statistics!

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And I’m sure you’ll agree it’s immense. This one is from a Lib Dem leaflet in Wantage, where Alex Meredith is the candidate. They have tried to get by on a technicality, using a broken blue bar to show that the Tory share is broken, but that negates entirely the need to include the bars at all, they are there to be a visual representation of the proportion of votes, but using a broken bar makes a mockery of this as the ammended heights suggest a close race, when actually the blue bar should be almost double the size of the yellow. Even with this technicality the bar is still wrong, as the rest bar should be half the size of the yellow bar but infact it’s less than one third. And yet again, Dave’s favourite slogan has reared it’s head. A terrible effort, here’s how it should look:

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While writing this post I asked people to send me any bar chart crimes that had come through their doors on election material, I particularly asked for non Lib Dem ones, yet the masses that came in all seemed to be theirs. I am beginning to worry that no one in one of the parties that has held government office for the last 5 years can grasp a basic bar chart. I’d be seriously worried if year sevens were making these mistakes. What’s worse is that there are tons of free websites that will do it for you, I used meta-chart for these. Or perhaps it’s just their policy to use misleading bar charts on their flyers. I am always on the lookout for crimes against statistics, so please do send me any you find, be they election related or not.

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  1. Paula
    April 22, 2015 at 8:52 pm

    I love your post! I am a constituent in Leeds North West – I never knew Greg was so famous for his graphs! I suspect the other parties here are just as bad. The crazy graphs drive those of us with any common sense mad. I no longer read sections of election communication if they include a graph. It would be a waste of my time as I’d just stand and gaze incredulously at it.

    • April 22, 2015 at 8:56 pm

      Indeed he is, or possibly infamous! I also live in leeds north west and have been checking all parties flyers for similar stats-crimes, but so far the only ones have been LD. I’ve not had any general election material from the tories as yet though, so maybe they’ve got a bad graph for us!

  2. April 23, 2015 at 9:24 pm

    Reblogged this on The Echo Chamber.

  3. April 23, 2015 at 11:13 pm

    This is one of the problems with education policy on Maths. The politicians know that if the vast majority of pupils learned data and statistics properly, the politicians would have to find a new narrative – they would be terrified of a properly educated electorate who understood the flaws in their arguments. And that is the best argument I can find for education in Maths as a politically subversive activity.

  1. May 17, 2015 at 5:00 pm
  2. May 3, 2016 at 9:47 pm

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