I just looked it up: https://en.wikipedia.org/wiki/Opinion_polling_for_the_2019_Australian_federal_election

Both polling results and election results were very close:


Without doing an in-depth research, I could only find figures with error margins for Ipsos:

The two-party result is based on preference flows at the last election, allocating second preferences from One Nation and United Australia Party using a split of 53 per cent to the Coalition and 47 per cent to Labor.

When voters were asked how they would allocate their preferences, the survey produced the same result of 51 to 49 per cent in Labor’s favour in two-party terms.

The poll is based on 1842 respondents who were surveyed from Sunday to Wednesday, in the wake of Mr Morrison’s official campaign launch, the announcement of his scheme to guarantee part of the loans made to some first home buyers and Mr Shorten’s promise of $10 billion in funding for a Melbourne rail loop.

The survey has a margin of error of 2.3 per cent and was conducted by telephone with 46 per cent of the sample based on mobile phone calls. — Ipsos

Their margin of error was 2.3%. Their result was off by 2.5%. "Total failure," really?


I don't see what this has to do with logic, mathematics or philosophy. At most, this is yet more evidence of innumeracy in the general population. By the way, the same hand-wringing accompanied Trump's election victory, where quality polls conducted close to the election were mostly right (i.e. their deviation was within their margin of error).

They were a failure when it happened with all of them over a long period of time. You should not be redlining a margin of error for at least a year before the election.

Another factor could be that publishing polling results influences how people vote and just who votes in an election.

If someone is consistently winning polling, it could (for just a few examples):

(a) influence people who would vote for the poll winner to relax and not bother showing up to vote (of course in countries where voting is not mandatory), because they figure "the poll winner is going to easily win anyway,"

(b) motivate people to vote who sometimes don't vote and who are supporters of the poll loser, because they think "the poll loser needs all they help they can get--I'd better show up and vote this time," and

(c) sway the vote of people who were on the fence--"I guess I'll give the poll loser a vote, because I'm undecided/I like/dislike both (or multiple) options more or less equally and the poll winner is going to win anyway, so I want to show some support for the loser/show lack of support for the winner."

People make predictions about what's going to happen in elections, and those predictions influence their behavior. Polling helps reinforce predictions, because "It's scientific and all that," so it has a strong influence on folks' behavior. It's similar to what happens with gambling. People make predictions, experts set odds, and that all influences how people bet, where people utilize that info to follow various strategies--they try to "game the system," but that can have relatively unexpected consequences.

So polling can be very accurate while not successfully predicting an outcome.

Please explain how the polls were a failure. Preferably with facts and figures.

Quite easily. All the predictions were wrong. Even if I accept that they were within the margin of error, that doesn't help. It should be so unlikely that that margin of error is used over that length of time. It's worth adding that Australian polls have a good track record so this is unexpected. I don't know how "facts and figures" help. I am sure that someone more mathematically gifted than I am could give the probaility curves for the margins of error and show how they shouldnt have come into it so often.

Polls can be expected to be wrong by a few percentage points sometimes. If they weren't then something strange would really be afoot. There might be some discussion to be had as to why they are wrong in particular instances, but there's nothing particularly strange about the Australian election. It was always predicted to be a close result and it was.

I don't know how "facts and figures" help. I am sure that someone more mathematically gifted than I am could give the probaility curves for the margins of error and show how they shouldnt have come into it so often. — orcestra

Well, facts and figures are obviously of no help to you - that was my point. When the margin of victory is as thin as that, margins of error will come into play. Really, when you see polls clustered tightly around 50%, even without inquiring after margins of error, you should realize that, as far as predicting the winner, a typical poll is pretty much a crapshoot.

One interesting thing about the election polls cited above is that, while any poll on its own was not wrong (or was not too far off), their combined result was. This is because when multiple polls of similar quality are averaged, their combined error margin is smaller than that of any single poll.

So if we take the average of the latest 5 polls in the table above (discarding the earlier Newspoll result), they give 48.6% for the coalition that ended up taking 51.5% of the vote. Assuming that all the polls had a similar margin of error (2.3% in the case of Ipsos), their combined margin of error is about 1%, which results in a gap of about 2% from the actual result.

Still, like @Baden said, a gap of a couple of percentage points is nothing to be hysterical about. The lesson for you is that when two competitors are going neck and neck like this, nothing short of a time machine is going to give you a very reliable prediction.

You would have a valid point if this degree of error were typical. But it hasn't been in Australian elections. Some of the polls have got the prediction wrong in previous elections. But not all pollsters and not for this length of time: I have to point out that this has bene the prediction and margin for almost all polls for the last 1 to 2 years; I'd need to check the exact time span but it's been a long time.

You cannot put the blame on polls for not getting the result right a year or two before the event. What do you think pollsters are - oracles? How would you distinguish inaccurate polling from people inaccurately predicting their choice two years into the future?

I vote NO :)