What are Phi Numbers?

This Sunday’s Observer has the first figures from PoliticsHome’s Phi5000 – these are figures from daily questioning of a panel of 5000 respondents by YouGov, recruited from the YouGov panel. What this isn’t is a normal YouGov poll, rather the Phi5000 is shamelessly prioritising tracking – the polls are weighted politically in the same way as YouGov’s polls so they aren’t skewed in a party partisan way, but beyond that representativeness takes a back seat to consistency, with the same people being questioned each day. This takes sample variation out of the picture – while the people within the 5000 who respond on a particular day might vary slightly, generally speaking if the figures change, the people on the panel must have changed their mind.

There are also downsides to this – being on an internet panel shouldn’t make you unrepresentative per se, but people willing to fill in a survey every day must be somewhat different to their peers (as would somone willing to do a phone survey everyday). Secondly, if was ever a risk of respondents being subject to a panel effect, it’s going to happen here. The most likely effect of that, and the effect I know Stephan is hoping for, is that members of the panel, aware they are going to be asked about their perceptions of issues of the day become more attentive to them, and the tracker becomes faster and more sensitive.

So what do we take from the first set of figures? The Observer today naturally concentrates upon the absolute figures – and there are interesting findings there – but that’s rather missing the point. What these are all about is the change, what underlying opinions are changing and at what point. Looking at the trends released there are no huge surprises so far – Brown and the government’s ratings have continued to plummet in the last month and more people now think the Conservatives would do better in government (that is a big change from when the same question used to be asked in the BrandIndex trackers, when however unpopular the government was, people didn’t expect the Conservatives would be much better).

The most interesting findings in these early figures are the ratings of party leaders. These are not from just asking yea or nay about individuals, but generated from a list of positive and negative perceptions – how many people think each man is strong, efficient, decisive, etc on one hand, or weak, incompetent or so on on the other. The net scores are the average proportion of people choosing each positive attribute for a leader minus the average proportion of people choosing each negative attribute for him. This produces several interesting findings – firstly, Nick Clegg is a positive for the Lib Dems, his net ratings are very similar to David Cameron’s, so when he trails in third place in things like best PM it’s probably just because he is a Liberal Democrat and because he is less well known than Brown and Cameron. Those who do have a perception of him as a leader have a relatively positive one.

More fascinating is looking at Brown’s underlying figures. His rating hasn’t slumped across the board, it’s only in specific areas. People haven’t just turned against him and given him bad ratings across the board – most of his ratings have been relatively stable and there has, for example, been little change in things like whether he is seen as “in touch”, “caring” or “sleazy”. Where perceptions have drastically altered is a leap in the proportion of people who said they thought Gordon Brown was “indecisive”, “weak”, “ineffective” and “out of ideas”, and a drop in the proportion of people who thought he was “competent”.

Perceptions of the other two leaders have been more stable. The increase in Cameron’s figures is pretty much across the board, just a warming towards him rather than any change in perceptions. The biggest changes for Nick Clegg are an increase in people who think he is “likeable”, “normal” and “intelligent” – the biggest drop in “None of the above” – his increase is from people gradually getting to know him. His percieved gaffe in talking about his past love life seems only to have made people think of him as a normal chap.