Back in 2012 I wrote about the Observer reporting an open-access poll on a website campaigning against the government’s health bill as if it was representative of members of the Royal College of Physicians. I also wrote to the Observer’s readers’ editor, Stephen Pritchard, who wrote this article about it.
The Guardian today is making the same error – they have an article claiming that seven out of ten junior doctors will leave the profession if the new junior doctor’s contract goes through. The headline presents it as representative of all junior doctors and it is referred to as a poll and a survey in the first two paragraphs. Only in the final, seventeenth paragraph is it revealed that it wasn’t conducted by any reputable market research organisation, but a self conducted survey of members of a Facebook group, the Junior Doctors Contract Forum, which is campaigning against the new contract (the Telegraph had a similar article earlier this month that appears to be based on the same data).
We cannot tell if efforts were made to limit the poll to actual doctors or to make it representative of junior doctors in terms of career stage, age, region and so on – it doesn’t really matter, as it is fatally undermined by being conducted in a forum campaigning against a contract. It would be like conducting a poll on fox hunting in the Countryside Alliance’s Facebook group and presenting that as representative of the countryside’s views on foxhunting. The flaw should be screamingly obvious.
Questions along the lines of “If thing you oppose happens, will you do x?” are extremely dubious anyway. The problem is that respondents to opinion polls are not lab rats, they are human beings who seek to use polls to express their opinion, even when it’s not exactly what the question asks. From a respondent’s point of view, if you are filling in a survey about something you oppose, you’re are likely to give the answers that most effectively express your opposition. Faced with a question like this, it’s far more effective to say you might leave your job if your contract is changed than say you’d meekly accept it and carry on as usual.
We see this again and again in polls seeking to measure the impact of policies. For example, before tuition fees were increased there were lots of polls claiming to show how many young people would be put off going to university by increased fees (such as here and here). After the rise, they miraculously continued to apply anyway. Nobody wants to tell a pollster that they would just swallow the thing they oppose.
I don’t doubt that many or most junior doctors are unhappy with the new contract, but you can’t get a representative poll by surveying campaigning groups, and you shouldn’t necessarily believe people telling pollsters about the awful consequences that will happen if something they don’t like happens. It’s a lot easier to make a threat to a pollster that you’ll resign from your job than it is to actually do it.
UPDATE: While I’m here in voodoo polling corner, I should also highlight this cracking example of a voodoo poll in the Daily Mail. It claims “One in three women admit they watch porn at least once a week”… but it seems to be an open access poll of Marie Claire readers, certainly it is in no way representative of all women in terms of things like age. It contains the delightful line that “Out of the more than 3,000 women surveyed, 91 per cent of the survey’s respondents identify as female, eight per cent identify as men and one per cent is transgender.” I don’t know how to break it to them, but you probably can’t include the 8% who are men in a survey of 3000 women.