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Is the polling correct?

(33 Posts)
GracesGranMK3 Mon 25-Nov-19 09:04:37

Last time it certainly wasn't. Almost all polsters got it wrong in favour of the Tories - or was it positive Tory headlines? Is the same thing happening again? This is probably of more interest for those who enjoy statistics so don't worry if your not one of those people. It's a bit of a read but I thought it worth copying in full.

Why the Observer’s opinion polling is wrong
Posted on November 24 2019
This comment was posted by a regular contributor who uses the name DunGroanin' in response to my discussion of the Observer's reported 19% opinion poll lead for the Tories. I tho0ught it worth sharing as it offers what seems like an entirely plausible explanation as to why the lead may be overstated:

I spent a lot of time last election blowing major holes in their balls polls, especially the commissioned ones by Opinium for the Obsessive Groaniad. Also one of the reasons why I done with them.

I called it pretty correctly. By looking at their RAW data. And I say the current tory lead is exactly what it was at the end of 2017. If you believe their raw data.

This time I hadn’t bothered up till now. Drilling down into data is the key. Even as the representation of the data has changed… in my opinion they have manipulated raw data!

The Obsessives splash yesterday that claims a headline of
‘Conservatives open up 19-point lead with 47% share of the vote’

Now understand that there is a catch-up period by Labour as the election campaign proceeds and fair coverage in the media allows that. Last time that ended with the overall lead of 800,000 votes over the whole 650 seats by the tories.

‘Despite a drop in the number of seats, the Conservatives actually saw a rise in vote share (up 5.5% points to 42.4%). Labour’s vote share rose at an even greater rate (up 9.5% points) and now sits at 40.0%.’


Remember that percentage – 2.4%.

Now lets drill down into the Opinium poll.

1. They state ‘Source: Opinium poll: 2,003 UK adults surveyed from 20 to 22 November 2019’ – that is 3 days over which the two thousand and three people were interviewed. Things were happening over these 3 days and doesn’t include the Friday debate.
2. In their new presentation of the data – There are now multiple data sheets. The relevant sheet is 5a. It asks what the responders voted in 2017, of the number that are used to derive the headline ‘result’.
3. The actual number of responders who voted in 2017 is a total of 1,368.
4. Off these 46% (508) voted Tory and 36% (421) Labour in 2017 – a difference of 10% not the 2.4% of the actual result remember!
5. The actual 2017 Tory share was 42.4% not 46% as of the responders. The actual Labour share was 40% not 36% of the responders. Self selected responders, many who couldn’t even ‘remember’ how they voted 2 years ago btw (ahem!).
So the Tory share of responders is over represented by 7.6% (4)
6. Then let us look at sheet 3 & 3b which mutates the numbers even further. The first has tory 35% (558) , Lab 23% (372). The second has tory 37% (585) , 24% Lab (379) – both have a total respondents used as 1592.
So the magic trick is pulled! How does my point 6 compare to my point 4?

I put all that up there not expecting most to follow it but to show the ‘data’. It can be ignored and you can just take my opinion below or their opium from Opinium (a firm that should hang it’s head in shame – i believe).


So how many ways to skin this very thin cat?

The raw data adjusted for the 7.6% starting variance would give the Tories a current lead (to the 3 day period ending 22/11) of between 4.4% and 5.4%.

With undecideds of some 16%.

I am sticking to my prediction of a landslide based on how the numbers improved through the campaign last time.

Anyway the 19% HEADLINE current lead is balls!

Do we really need to wonder why such magical thinking is going on in the Obsessive Groaniad?

MaizieD Mon 25-Nov-19 09:12:46

Leavers have spent the last 3 years telling us not to believe polls, but now they believe them implicitly because they predict a Johnson majority. Funny old world, isn't it?

They won't read your OP, GGMk3. Too many words in it...

ladymuck Mon 25-Nov-19 09:15:30

True, MaisieD. I was all set to read it but it went on for too long.
I despair for the future of this country, whoever wins.

GracesGranMK3 Mon 25-Nov-19 09:17:30

I know Maizie. Sad isn't it. I feel we should know about these things.

GracesGranMK3 Mon 25-Nov-19 09:19:34

Perhaps this is the most important bit re the result for Labour.

I am sticking to my prediction of a landslide based on how the numbers improved through the campaign last time.

humptydumpty Mon 25-Nov-19 10:16:25

We can only hope.

Urmstongran Mon 25-Nov-19 10:19:15

We will know the answer on 13 December!

I think people do lie to pollsters and say one thing yet do another in the privacy of the polling station.

GracesGranMK3 Mon 25-Nov-19 10:22:05

It isn't about people lying to pollsters UG, although it was a bit of a read. It's about pollsters misinterpreting the raw figures in the same way they did at the last election.

JenniferEccles Mon 25-Nov-19 11:00:03

Polls or no polls the fact remains that the vast majority of people wouldn’t dream of voting for an extreme Leftist party which Labour has become.

That is a fact.

Of course there will be a few gullible folk who will fall for Labour’s idiotic spending proposals but thankfully they are in the minority.

GracesGranMK3 Mon 25-Nov-19 12:39:30

That is your opinion JE - with no reference to any proper figures to back it. If the polls are inaccurate then it is also not true. As this is exactly what happened in the last election then it is totally reasonable to ask the question. If they are making the same mistake it is another lie in favour of the extreme right.

I rather think that calling fellow members "gullible" and suggesting that a party that is not as far to the left as some of, for example, the Nordic countries with their high standard of living just makes you seem even less credible and more "gullible" for swallowing, hook, line, and sinker the lies you have been fed.

jura2 Mon 25-Nov-19 13:08:28

Well Jennifer, we both have - because the alternative, with Johnson is absolutely terrifying.

Tories have borrowed 1 trillion in last 9 years- over 100 billion a year. 7.5 times more in 9 years than Labour in all their years in power (33 years in total).

Tooting29 Mon 25-Nov-19 13:19:08

There is only one poll that counts and that is the one on 12th Dec. Prediction /forecast is just that an educated guess and not a statement of fact.

Jane10 Mon 25-Nov-19 13:39:08

I certainly take polls with a large pinch of salt. As previously stated its the one on 12th December that counts!

Sussexborn Mon 25-Nov-19 13:42:03

Oh dear GGMk3! How much time did you spend/waste on your (wo)mansplaining? It must be hard living in this world of wrong thinking morons!

My Nordic friend got a terrible shock when her Mum had a stroke! Life there was far tougher than she had realised from her holiday visits! The reality was far harsher than here and a huge wake up call.

Sussexborn Mon 25-Nov-19 13:48:14

PS I did read it despite the patronising comments!

Politeness and manners seem to have been swept aside and I wonder if they will reappear after the 12th! I really hope so.

Yehbutnobut Mon 25-Nov-19 14:07:49

We were polled the other day in Liverpool. We blithely informed the young woman that we (all six of us) would be voting for Boris. It must have been clear to her that we were taking the piss, but she ticked her little boxes so she could ‘get polling done’!

GracesGranMK3 Mon 25-Nov-19 14:37:22

Tooting29 There is only one poll that counts and that is the one on 12th Dec.

I don't agree. The poll on the 12th can be influenced by headlines saying one or other party is ahead. If these are as massively incorrect as it appears they could be then these are basically more lies heaped on the lies we already have.

Perhaps this will one day be called the liars election in honour of Mr Johnson (and a few people of social media).

Jane10 Mon 25-Nov-19 15:06:15

The polls are only what people say they are going to do. What they actually do is something else altogether. Do you really think that polls themselves affect outcomes? People aren't that daft.

GracesGranMK3 Mon 25-Nov-19 15:30:40

No Jane they are not. A random sample would have to be huge. This is a small sample, which can give you an accurate answer, but needs to properly reflect an accurate cross section.

Oopsminty Mon 25-Nov-19 15:39:39

I never believe polls

GracesGranMK3 Mon 25-Nov-19 16:34:00

That's about as useful as always believing them. You just need to be sure they know what they are doing and are doing it right.

Jane10 Mon 25-Nov-19 16:39:08

Sample selection is an art that several of the polls I've been involved with don't seem to have mastered. I actually withdrew from them as they are just so easy to fool (if one wanted to). Another issue I disliked was the way my responses were funnelled down particular channels depending on who had commissioned the poll. As a result I ignore polls.
Bookies odds are often worth a look though!

grapefruitpip Mon 25-Nov-19 16:42:59

extreme Leftist party which Labour has become.

Many people won't be voting for an extreme Rightist party headed by a big liar.

Tooting29 Mon 25-Nov-19 16:48:52

True. Polls are just part of the story. Opportunities to scaremongery OMG Boris one or the other might get electedshock. They are of interest to the political parties to assess how the campaigns going and get vote out, or a focus to discuss on the media. I find them interesting but do they influence my vote probably very little.

GracesGranMK3 Mon 25-Nov-19 17:00:47

I think most of the parties now have their own polls carried out. The one referred to in the OP was done for the Observer but it seems to have the same issues as the polls for the papers carried out in the last election.

It's not an 'art' Jane10, it's a science but in this Liar's Election who can believe anything.