I blogged earlier today about how the Mirror bigged up a poll showing Tory support unchanged (within the margin of error) into a story of how their support was plunging.
But looking again at the story, I realise just how badly wrong their graph is.
The two key pieces of information about Labour’s rating in the poll are that:
(a) It was 30%
(b) It was 32% in the previous poll
Now look at the graph:
See what’s happened? What should be a downward Labour line has become a flat line and the end which should be at 30% is actually put at about 31%. Both the trend and the end point are wrong – and both in ways that flatter Labour.
Not good at all.
(You may notice that the Tory point also looks like it may be a little on the low side too, but having deployed ruler and calculator the overall impact on the graph is to make the Tory-Labour gap 25% smaller than it should be. Plus the Labour line is flat rather than down.)
Share:
15 Comments
“You may notice that the Tory point also looks like it may be a little on the low side too, but having deployed ruler and calculator the overall impact on the graph is to make the Tory-Labour gap 25% smaller than it should be. Plus the Labour line is flat rather than down.”
It doesn’t sound as though you’ve looked at many “two-horse” race graphics recently, if you think that kind of thing is bad!
Actually, if you have a look at the MORI page on Anthony Wells’s site (http://ukpollingreport.co.uk/blog/voting-intention/mori) you’ll see what happened. The Mirror used a graph that only went up to last month’s figures.
It shows (admittedly not very accurately) last month’s lead of 37-32, which oddly enough is the same as this month’s one of 35-30.
It terms of the scale of the gap between the Labour and Tory line, I think you’ll find that that’s a function of the line style used in the graph, so the actual datapoint is located at the midpoint of a straight line across the base of the arc used to round-off the end of the line.
Its the width of the lines, coupled with the rounding of the terminator and the relative direction of the two lines that makes the gap appear smaller than it should, strictly speaking, be – although that may still be a deliberate choice on the Mirror’s part.
The big inaccuracy in that graph is actually in the position labelled “Brown comes to power”. He came to power at the end of June 2007. The graph goes from something more like the end of September, omitting out the first three months of his premiership, when Labour had a clear lead over the Tories.
Unity: I did wonder if that was the case, but if that’s the case and you take the Con/Lab end points as right, then other points on the graph (and gaps between them) are wrong, i.e. it doesn’t work as an explanation that then makes the whole graph correct.
Mark
For the explanation, see my post at 11.56 above.
If you want bias may I direct you to The Sun newspaper. Looks like if Rupert Murdoch doesn’t like it then it is bad for everyone. Because Rupert Murdoch is representative of the man on the street, isn’t he?
So the Mirror is true to the ethics of it’s political masters lying, cheating and deceiving at every turn. Well spotted Mark but did anyone really expect anything different? Keep it up and keep an especially close eye on Labours PR team at the BBC.
This is a bit rich coming from a Lib Dem – the party that is congenitally incapable of publishing an accurate and truthful graph on its election propaganda: “Only the Lib Dems can beat Labour/the Tories” accompanied by a crassly misdrawn bar chart.
http://cyberboris.wordpress.com/2010/03/25/boris-and-gordon-are-polar-opposites/
The Mirror do things like that all the time, they make half of the political news up. It is all totally biased to Labour, just like Question Time and the BBC. You wouldn’t have such blatant distortion if Boris were our PM.
They’ve also used really thick lines, which has the visual effect of making the gap between the parties look narrower than it actually is.
With graphs like this, you wonder if these guys used to run Lib Dem constituency campaigns
Dr Freud,
I have been responsible for many graphs/ bar charts over the years. They have always been mathematically correct.
Angela,
But if Boris was PM would he meddle in bus operations EVERYWHERE ????
I love the way the other parties continue to peddle the lie that it’s the LibDems with the dodgy barcharts.
Yes I’ve seen some dreadful ones on focus leaflets, but if you take a look through The Straight Choice you’ll see poor charts from every party, including this great one from UKIP.
Ryan (who ensures that all charts on my leaflets are correct to the nearest millimetre).
HA! A Lib Dem complaining about dodgy graphs!
I point you to any Lib Dem leaflet for all the dodgy graphs and mathematics you’d possibly need!
As I said in answer to a previous comment on Twitter Clarity, I’m happy to defend any graph that I’ve produced. Can you point to one you’d dispute, or perhaps you’re not quite accurate with your own comment
5 Trackbacks
[...] on with the round-up, a special mention has to go out to Mark Pack over at Lib Dem Voice for catching The Mirror’s art department playing silly buggers – nice one [...]
[...] Ooops! Mirror gets poll graph wrong and inflates Labour’s position (13) by Mark Pack. 2. Were there two YouGov polls for the Sunday Times? (3) by Mark Pack. 3. [...]
[...] details of – being a fairly basic standard to aim for, we’ve had such low lights as the skewed graph in the Mirror along with its over-hyped language and the Sunday Times so twisting the findings of its own poll [...]
[...] a bow, Sunday Mirror who seems to be following in the footsteps of the Daily Mirror. Share this story with your [...]
[...] Take a bow, Sunday Mirror who seems to be following in the footsteps of the Daily Mirror. [...]