Showing posts with label sample noise. Show all posts
Showing posts with label sample noise. Show all posts

Saturday, December 22, 2018

EMRS: Small Swing To Labor In Tasmanian Federal Poll

EMRS Tasmania (federal) ALP 40 (+2.1 since election) Lib 33 (-2.4) Green 11 (+0.8) Others 15 (-1.4)
Overall poll suggests a no-change seat result in Tasmania would be likely if election held now
Individual seat results must be treated with caution because of small sample size.

The Liberal Party suffered a major blow early on federal election night 2016, losing the three northern Tasmanian seats that it had captured from Labor in 2013.  In the leadup to the 2019 election, the Tasmanian federal seats have so far not attracted much attention.  This is consistent with a national feeling that with a substantial swing to Labor likely, only a few Labor seats are likely to be in play, and typically where so for unusual local reasons (Lindsay, Macnamara for examples).  The Coalition's strategy is likely to be focused on trying to save as many of its own seats as possible, and going hunting for gains in Tasmania (where PM Morrison has never been high-profile) doesn't seem like a high-payoff-chance strategy.  The northern Tasmanian seats are also protected by personal vote effects for new sitting members, making them harder to shift (not that this stopped them from flipping last time.)

Friday, August 3, 2018

"Margin Of Error" Polling Myths

A lot is said about "margin of error" in public discussion of opinion polls, and nearly all of it is wrong.

This is another piece I've been meaning to write for quite a while.  There are many other articles about this on the web, but I'm not aware of any that make all the points I'd like to make and make them in an Australian context.

The concept of "margin of error" is one that is commonly talked about in discussion of polls.  It is often used to (rightly) deflate breathless media babble about movements in polls that are supposedly caused by whatever the media pundit wants to see as the cause, but in practice are often nothing more than random variation from sample to sample.  Possum's Trends, The Horserace and Random Numbers (2012) was a classic debunking of that sort of commentariat nonsense, written in the days of the older, much bouncier Newspoll.

Unfortunately, of all the things that get talked about in polling, margin of error is probably the concept that best shows that "a little learning is a dangerous thing".  People grasp the basic principle and misapply it constantly - and are assisted by pollsters, the media and even the Australian Press Council's otherwise good (and too often disregarded) poll-reporting guidelines in doing so.