January ComRes poll before turnout weighting:
January ComRes poll after turnout weighting, published numbers:
February ComRes poll before turnout weighting:
February ComRes poll after turnout weighting, published numbers:
So as you can see, there's no automatic significance to the unweighted numbers showing a small No lead - it has already happened this year, and is perfectly consistent with the possibility of a Yes lead on the headline numbers. And yet, last night, Scotland on Sunday published the unweighted numbers from a new ComRes poll and presented them as if they were headline numbers. They tried to make out that the No lead was a significant departure from previous polling and had been caused by the Sturgeon-Salmond controversy, when in fact the numbers were literally identical to the February poll that had Yes ahead by 53% to 47% once undecideds were excluded. That doesn't necessarily mean, incidentally, that Yes must be ahead on the weighted numbers, but it does mean that we simply don't know - there could be a Yes lead, a No lead, or a dead heat.
So what the hell are Scotland on Sunday playing at? The short answer is "I've no idea", but here are a few logical possibilities...
* The poll contained both weighted and unweighted numbers, as per usual, but Scotland on Sunday disliked the weighted numbers and ran the unweighted ones instead. That would be, not to put too fine a point on it, utterly outrageous.
* The poll was half-finished and the weighted numbers weren't available yet, so to meet a publication deadline Scotland on Sunday decided to just run the unweighted numbers. That would be downright amateurish.
* The poll was never intended to be a Yes/No independence poll, and therefore ComRes didn't collect enough information to produce turnout weighted numbers. But when the raw data suggested a No lead, Scotland on Sunday couldn't resist retrospectively turning it into a Yes/No poll to produce damaging headlines for the SNP, even though they'd been warned the numbers were unreliable. That would be pretty cynical.
Wherever the truth lies, it's hard to think of any explanation that doesn't involve a heavy dose of shoddy journalism.