In what’s turning out to be a bit of a Roy Morgan day, they’ve released another telephone poll taken over the period of June 10/11 – although there’s no link yet except the poll appearing on their trends page. It has the primaries running 47.5 (up 4.5) / 37 (down 2.5) to Labor, washing out into a two party preferred of 57.5/42.5 the same way – a 2.5% increase to the ALP since the last poll taken on June 3/4.
This poll only has a sample size of 715, compared to the previous poll with a sample of 805 – so the changes aren’t statistically significant. With these samples being relatively small, the margins of error for each poll are relatively large (around the 3.5% mark give or take a few tenths) – leading to the interaction of these two large MoE’s creating an even larger “width” of potential outcomes that could be occurring to the true value of public opinion underneath the headline data.
However, and this is one of the reasons I created The Poll Cruncher – we can look beyond the statistical significance and determine the approximate probabilities associated with these results.
For instance, on the two party preferred vote there is an approximate 83% probability that the true underlying value of public opinion shifted over the last week to now be above 55%. There’s an approx 71% probability that the shift was greater than 1 point on the TPP and a 57% approx probability that the shift was greater than 2% to Labor.
On the other hand there is a 16% probability that the true underlying level of public opinion shifted against the ALP.
On the primary vote, there is an approximate 80% probability that the ALP primary vote increased by 2 points or more and an approximate 92.2% probability that it increased by 1 point or more.
On the balance of probabilities, it is likely that the ALP – from this phone poll data at least – has experienced a gain in their polling over the last week, the week when the Rudd Recession failed to turn up.
So watch out for movement to the ALP in Monday’s Essential Report and Tuesdays Newspoll.On the balance of probabilities and the simple maths – we should expect to see a move to Labor, it is more likely to occur than not.