Scottish referendum poll tracker
On 18 September 2014 millions of Scots will vote on whether they want their country to become independent or remain part of the United Kingdom. But what do opinion polls suggest about which way the decision will go?
Explore our poll tracker and check key political events along the way.Continue reading the main story
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Scottish Referendum poll tracker -- read the full methodology.Continue reading the main story
David Cowling, Editor, BBC Political Research Unit
Opinion polls are already playing a significant role in the referendum and it seems likely that this will continue as the campaign intensifies.
As each side tries to create momentum, the polls are used to batter their opponents. But where does that warfare leave individual electors as they seek to discover possible outcomes?
Traditionally, we describe polls as temperature readings valid at the time they are taken.
Individual polls are important, but we should also be looking at any trend over time: is the direction of travel benefiting one side or the other?
However, it is also important to look beyond the headline poll figures for "Yes" or "No".
Most polls will ask respondents how certain they are to vote: are the supporters of one side more enthusiastic about voting than those of the other: pollsters will often adjust their referendum voting figures to take account of any such differences.
We are told that perceptions of how the Scottish economy will fare in the event of independence will be important in deciding how people vote.
We know that older people have a greater propensity to vote than younger age groups: how do they split between the two sides?
Polls to date have shown a marked gender gap, with women much less likely to support independence than men: as we enter the home stretch of the campaign does that gender divide hold, or do women become more favourable?
These few examples suggest that there is much more to be gleaned from the polls than is gained from the published referendum voting intention figures alone.
And this campaign will be a real test for the polling companies themselves.
You would think, given the choice is simply "Yes" or "No", that the challenge to produce accurate figures would be relatively simple; but predicting the same "Yes" or "No" choice in the 2011 UK referendum on the Alternative Vote system caused some pollsters grief.
The September referendum has no precedent for the pollsters to measure their 2014 poll results against.
We need to keep that in mind as the campaign develops and the tide of opinion polls sweeps over all of us.