Lies, damned lies, and statistics?

According to Jim Fitzpatrick, the BBC’s Politics Show on Sunday will be looking at that NIO poll and the issue of devolving policing and justice powers – let’s hope they check their figures because the line in the article, “The Northern Ireland Office has just published a survey which shows a whopping 61% of DUP voters support devolution of policing and justice powers. 14% of them apparently believe May isn’t soon enough.” isn’t matched by the figures in other reports.. [subs req] There’s been no update on the BBC’s Mark Devenport’s figures. And if they do check those figures perhaps they’ll consider the apparent anomaly in the poll results noted yesterday. That apparent anomaly is that the reported overall figure from the survey for support for the devolving of policing and justice powers by May 2008 was just 53% – lower even that that reported from DUP supporters. In his article Jim Fitzpatrick gently queries the poll, “This means that either the survey or the DUP is hopelessly out of touch – you decide.” But where are the figures for supporters of the other parties? Update The poll results are available here [pdf file]From the Irish Times report [subs req]

The survey of 1,422 people carried out by Millward Brown Ulster in January found that 55 per cent of DUP supporters thought devolving justice by May was “about right” while 5 per cent thought it should happen sooner. It found that 27 per cent of DUP supporters thought May was too soon for this devolution while 13 per cent of DUP people did not know whether it should happen by May.

We’ve yet to see the comparative figures for supporters of other parties.. assuming they were asked in the survey. And those comparative figures could be very important.

The apparent anomaly in the survey results – of higher support from DUP supporters than in the wider public for devolving those powers by May – can be easily explained.

The apparent anomaly is that the reported overall figure from the survey for support for the devolving of policing and justice powers by May was just 53% – lower that that within the DUP.

If, for whatever reason, people surveyed who supported devolving those powers by May but were not DUP supporters ended up being counted as DUP supporters then that would artificially inflate the figures for support within that party whilst leaving the overall figure unchanged.

But, if that happened, it would affect the survey figures on support for devolving those powers by May within the other parties. Of course we don’t have an earlier poll to compare those figures to – even if we did have them.

Update It seems we do have those comparative figures and a previous poll from September 2007 – the results of the latest poll, and comparison with previous, here [pdf file]

On May 2008 As The Target Date For Devolving Responsibility For Policing And Justice To The Northern Ireland Assembly

NIO poll

And, as expected, three parties show decreases in support for devolving policing and justice powers by May 2008 – the UUP, down 4 points, the Alliance Party, down 7 points, and Sinn Féin, down 4 points.

Additionally, all parties, with the exception of the SDLP, show increases in the percentage of supporters who think May 2008 is too soon.

And the percentage overall who support the devolving of policing and justice powers, at some point, has dropped from 62% to 60%.

No actual figures given for how the sample breaks down by party supporters, not even a percentage. No methodology. And no non-party-aligned respondents.

Adds It’s also worth noting that according to another set of figures within the same poll support for devolving policing and justice powers, at some point, has dropped within the DUP by 8 points, within the UUP by 4 points and within the Alliance Party by 3 points. According to one set of figures in the poll that is..

On whether policing and justice powers should be devolved at all
NIO poll

And, again, no actual figures given for how the sample breaks down by party supporters, not even a percentage. No methodology. And no non-party-aligned respondents.

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  • joeCanuck

    The problem is that 2 does not equal 3; even for extremely high values of 2.

    ..Anonymous mathematician/statistician.

  • kensei

    Pete

    And the percentage overall who support the devolving of policing and justice powers, at some point, has dropped from 62% to 60%.

    Since this whole post is amount damned lies and statistics,what is the statistical margin of error on the poll?

  • Jim Fitzpatrick

    Apologies about those figures – my eyesight is obviously failing as I quoted figures from Septempber rather than January.

  • Pete Baker

    Jim

    I’d blame the presentation of the figures by the NIO – it’s almost as if they intended to confuse.

    But those particular figures – the answers to the first question on support for devolving policing and justice powers – are worth focussing on.

    When asked the straight question, on whether those powers should be devolved, according to the NIO’s polls support within the DUP has dropped by 8 points, from 61% to 53%, since September 2007.

    No wonder the NIO are pointing everywhere else..

    ken

    We don’t even have the margin of error – which is kind of the point.

  • Yvonne

    People using statistics to confues people. Has this ever happened before?