Comments on: Public Poll Average Calculations

By: Electorate seats « Kiwi Poll Guy

Electorate seats « Kiwi Poll Guy — Wed, 18 Nov 2009 02:25:37 +0000

[...] General Election. This is the zero-knowledge solution, and is used by David Farrar for his Curiablog public poll average calculations [actually, it's a bit more complicated, see [...]

By: southernhunter

southernhunter — Thu, 06 Nov 2008 02:17:36 +0000

Comment for Curia: I have noticed an error in the version of the spreadsheet live on 6 Nov. The calculations show 35 electorate seats won by national, but the estimate of which national candidates will get in on the list uses 36. Hence you are showing 24 List MPs, not 25.

By: trevva

trevva — Sun, 19 Oct 2008 13:12:10 +0000

After some thought and closer analysis, I am able to confirm that what truthseekerNZ is saying actually has some statistical merit. The test I discussed in the previous post still holds – no polls show statistically significant deviations from zero bias. However, what truthseekerNZ is discussing are the relative values of Labour and National (ie that a particular poll shows a significant greater (or lesser) bias towards one party than the other). I tested this statistically – the results are shown on the updated version of this figure:

http://en.wikipedia.org/wiki/Image:NZ_Elections_2005-2008_-_party_bias.png

The analysis shows that Colmar Brunton and Nielsen show a statistically significant bias towards the National Party, and TNS has a significant bias towards the Labour Party. There is no evidence, at the 95% level, of there being a bias in the Digipoll, Roy Morgan, or UMR poll results towards either of the major parties.

By: trevva

trevva — Fri, 17 Oct 2008 08:38:02 +0000

I would tend to disagree about the issue of biases. I’ve been looking at this myself over the last few weeks – it started with the production of the graphs on this wikipedia page:

http://en.wikipedia.org/wiki/Opinion_polling_for_the_New_Zealand_general_election,_2008

I’ve used that set of data to analyse the deviations from the “mean” line by polling agency. The results are here:

http://en.wikipedia.org/wiki/Image:NZ_Elections_2005-2008_-_party_bias.png

Note these are “relative biases” – to get the absolute bias, multiply the value by the current estimate of party support.

I’ve analysed these biases statistically. The basic conclusion is none of the biases are statistically significant, either at the 95% or even the 90% level. I was suprised by this initially, but when you look at the whiskers in the box and whiskers plot, you can see that all of them cross the zero-bias line.

I would therefore conclude that the variation within the surveys is generally larger than any systematic biases.

By: truthseekernz

truthseekernz — Thu, 16 Oct 2008 19:44:45 +0000

In the NZ Herald on Wednesday, Brian Rudman highlighted how the Colmar-Brunton Poll and the Fairfax polls both tend to over rate National’s poll support by 6% to 8%…..and I’d say sometimes even more. The TNS polls and the Morgan polls have consistently been the most accurate. The Herald Digi-poll has recently joined the ranks of the over-raters since that newspaper fell in love with the National party editorially over the past 3 years.

having these three major polls all echoing the same recorded bias in favour of one party surely must corrupt any attempt to create a meaningful average of polls.

The Herald’s own “informal” poll reported by Simon Collins 3 weeks ago was the first poll of the recent three that show the race to be much closer (National on 43.5%) than the three polls we know to favour National.

Polls everywhere are showing evidence of corruption as what they indicate is often far from the actual result at the polling booths……and they put it down to an “overnight shift”…..whereas I’d put it down to months of trying to make their political desires into reality by reporting shonky polling results.

By: Caching and Wordpress | Kiwiblog

Caching and Wordpress | Kiwiblog — Fri, 26 Sep 2008 21:56:53 +0000

[...] people will have seen the sidebar graphic with the Curiablog poll average. I update it everytime there is a new poll by replacing the graphic file at curiablog with a new [...]

By: goonix

goonix — Thu, 11 Sep 2008 21:43:57 +0000

It’s pretty difficult to read the ACT (and Greens). Perhaps stronger colours could be used?

By: United Future not interested in Sth Island « Homepaddock

United Future not interested in Sth Island « Homepaddock — Sun, 07 Sep 2008 18:33:40 +0000

[...] a statistician so no doubt he’ll be able to work out that at current polling which puts UF at .5% the odds of him getting in to parliament and his party having a South Island [...]

By: The 2008 Labour Party List | Kiwiblog

The 2008 Labour Party List | Kiwiblog — Sun, 31 Aug 2008 03:36:07 +0000

[...] that leaves Labour with 24 electorate seats. On the time and date weighted average of the public polls, Labour has 36.3% and there is 3.2% wasted vote giving them an effective vote of 37.5%. That would [...]

By: National’s 2008 Party List | Kiwiblog

National’s 2008 Party List | Kiwiblog — Sat, 16 Aug 2008 23:51:32 +0000

[...] based on its party vote. Now we do not know what vote National will get, but let us go off the date and time weighted average of recent polls at curiablog which has National at 50.9%. One also then needs to work out what National’s share of the [...]