Opinion polls have been poorly reported and poll details have been hard to find. The latest Colmar Brunton poll is a major improvement.
Most polls have been dominated by associated media organisation news reports that have often had very narrow headlines that ignore how polls work as they try to create headlines. This still seems to be the case with the One News and 3 News polls reported on Sunday and Monday, but a least if all the relevant poll information is made available it’s possible to evaluate much wider implications.
Roy Morgan has been good at presenting their polls factually and with very good explanatory poll information – see their last New Zealand political poll which includes a link to extensive poll data.
New Zealand based polling companies are all linked to media organisations, and they have been big on making up headlines and poor at providing details.
Sunday’s 3 News poll coverage headlined Poll: National up, despite Oravida saga and gave all all party results but over dramatised without justification.
And New Zealand First is on 4.9 percent. It is so close, but leader Winston Peters would not make it back. If he got that little bit extra to 5 percent, it would change everything.
It wouldn’t necessarily “change everything”, 0.1% is statistically irrelevant. At 4.9% (with 95% confidence with a sample size of 1000) the margin of error is +/- 1.4% giving a range of 3.5-6.3. That’s an approximately 50-50 chance of making the threshold – and research shows that polls tend to under-measure NZ First support.
3 News linked to READ MORE: Full 3 News Reid Research results but this is very disappointing. It did have some detail and some standard poll information but it is inadequate.
It included a “projected number of seats” that means little this far out from the election. Worse, it excluded NZ First from the seat count despite a strong statistical confidence of them making Parliament but it includes the Conservative’s with 2 seats despite there being no statistical or factual basis for them winning an electorate seat.
One News coverage of their poll on the same day further emphasises the nonsense of making definitive predictions based on a single poll. Their headline was NZ First the big winner in poll.
Winston Peters is likely to be the man other party leaders are lining up to make deals with after the election, according to the latest ONE News Colmar Brunton political poll.
New Zealand First is the poll’s big winner, its support more than doubling to 7% this month.
Apart from this significant difference One News gave very superficial poll results, with percentages rounded to the nearest whole number and small parties that didn’t make 1% were ignored as if they had not featured in the poll at all.
And One News had no link to poll details or explanations. This is very poor.
In contrast One News’ polling company Colmar Brunton has provided extensive poll details – if you look for it.
On their Current ONE News Colmar Brunton Poll website page they have a poll summary only (again excluding sub 1% parties) but they provide detailed polling information, including:
Note: The interview introduction was changed in this poll to remove any reference to politics, and the weighting specifications were updated. This may impact comparability with the previous poll.
Please click here to download the ONE News Colmar Brunton Poll report, or read more at the TVNZ politics page.
The poll report gives extensive poll details with polling history, charts and wording of questions plus relevant commentary. They also include detailed methodology.
CLIENT: Television New Zealand.
RELEASED: Sunday 30 March 2014.
POLL CONDUCTED: Interviewing took place from Saturday 22 – Wednesday 26 March 2014.
MEDIAN FIELDWORK DAY: Monday (50% of sample size target typically reached on this day).
TARGET POPULATION: Eligible New Zealand voters.
SAMPLE POPULATION: Eligible New Zealand voters who live in New Zealand households that have a landline telephone.
SAMPLE SELECTION: Nationwide random digit dialling of landline telephones using stratified probability sampling to ensure the sample includes the correct proportion of people in urban and rural areas. Interviewers ask to speak to the person in each household aged 18 years or over with the next birthday. When required, multiple calls are made to reach that person. Voting eligibility is determined at the first question.
SAMPLE SIZE: n = 1,003 eligible voters.
SAMPLING ERROR: The maximum sampling error is approximately ±3.1%-points at the 95% confidence level. This is the sampling error for a result around 50%. Results higher and lower than 50% have a smaller sampling error. For example, results around 10% and 5% have sampling errors of approximately ±1.9%-points and ±1.4%-points, respectively, at the 95% confidence level.
These sampling errors assume a simple random sample of 1,000 eligible voters.
INTERVIEW METHOD: Conducted by CATI (Computer Assisted Telephone Interviewing).
WEIGHTING: The data have been weighted to align with Statistics New Zealand population counts for age, gender, household size and ethnic identification.
REPORTED FIGURES: Reported bases are unweighted. For Party Support, percentages have been rounded up or down to whole numbers, except those less than 5%, which are reported to 1 decimal place. For all other figures percentages have been rounded up or down to whole numbers except those less than 1%, which are reported to 1 decimal place.
METHODOLOGY NOTES: The party vote question has been asked unprompted since February 1997.
The interview introduction was changed in this poll to remove any reference to politics, and the weighting specifications were updated. This may impact comparability with the previous poll.
The data does not take into account the effects of non-voting and therefore cannot be used to predict the outcome of an election. Undecided voters, non-voters and those who refused to answer are excluded from the data on party support. The results are therefore only indicative of trends in party support, and it would be misleading to report otherwise.
This poll was conducted in accordance with the New Zealand Political Polling Code. Publication or reproduction of the results must be acknowledged as the “ONE News Colmar Brunton Poll”.
It’s worth repeating this:
The data does not take into account the effects of non-voting and therefore cannot be used to predict the outcome of an election. Undecided voters, non-voters and those who refused to answer are excluded from the data on party support.
The results are therefore only indicative of trends in party support, and it would be misleading to report otherwise.
One News and all journalists reporting on polls should learn this thoroughly.
Kudos to Colmar Brunton for providing all this information. If One News and other media organisations and polling companies did likewise, and if political journalists did Polling 101, political polls would be less abused and better used.