Political Polls in New Zealand Dru Rose C

Political Polls in New Zealand Dru Rose C 1, L 2, S 1

There are 6 main poll companies: • • One News Colmar Brunton Herald Digi. Poll 3 News Reid Research Herald on Sunday Key Research • Roy Morgan • Horizon Dru Rose C 1, L 2, S 2

Colmar Brunton, Digi. Poll, Reid, Key and Roy Morgan use CATI Computer Assisted Telephone Interviewing Dru Rose C 1, L 2, S 3

and RDD (Random Digit Dialling) • Computer software randomly rings a household with a landline telephone. The interviewer asks to speak to the adult with the most recent birthday. • If that person is not at home, the CATI software usually programmes several re -calls over a 4 -day period in an attempt to contact them. Dru Rose C 1, L 2, S 4

Dru Rose Some form of Stratified Sampling is used which samples • Geographic regions • Rural/urban • Gender • Age • Income distribution • Ethnicity in approximately the same proportions as in the population C 1, L 2, S 5

Non-Sampling errors • Selection bias (RDD-landlines only) • non-response/don’t know bias Dru Rose The 5 main poll companies first exclude non-voters and then those with no firm preference (undecided) Poll %s are for decided voters only (These polls usually produce predictions close to actual election results for the two main parties) C 1, L 2, S 6

Dru Rose Horizon Poll • Horizon polls are on-line. • People are invited to join the Horizon. Poll national online research panel based on the profile of the population at the 2006 census. • Large Sample size 1800+(to provide sufficient respondents from minor parties) • Weight by age, gender, ethnicity, region, personal income and party vote (2011). • Includes both decided voters and undecided voters leaning towards a preference • called a Net Potential Vote poll. C 1, L 2, S 7