Monday, January 05, 2009

Summer statistics

Half of all New Zealanders want Christmas moved! That’s nonsense, of course, but no less silly than a recent news story headlined*, “Half of Kiwis want summer break moved to February”.

In fact, the survey found “44 percent of the people believe that the summer holiday period should be moved from December to February, when the weather is warmer, compared to 51 percent, who would like to leave it as it is. Another 5 percent were undecided.” Okay, I admit mathematics wasn’t my strongest subject in school, but 44 percent is hardly “half” and 51 percent is more than half. Wouldn’t it be more accurate, especially adding the “undecideds”, to say “more than half of New Zealanders are happy with summer break where it is”?

I questioned the validity of a previous survey result from the survey outfit, Research New Zealand, and while I’m too lazy to dig deeper into this survey (it is summer break, after all), I tend to be suspicious of this one, too. Okay, here’s one raised eyebrow: The news story says the survey “was conducted by telephone between November 26 and December 3”, a period with some cool and rainy weather as we waited for warm summer to begin. We should expect the respondents to have been yearning for summer. The results might be more valid if the survey had been conducted in January.

However, the survey company isn’t the issue as much as that journalists seem incapable of looking at statistics with anything even close to a critical eye, much less a sceptical one. So much of modern policy is driven by opinion polls and other statistical research that journalists do a huge disservice to the public when they can’t seem to grasp statistics or polling data. And you don’t need a survey to tell you that.

*Update: Since I first read the online story linked to above, the headline has been changed to "February summer holiday idea finds favour" which is accurate. It turns out that website comments (which I seldom read) raised the same objection to the headline that I did.

No comments: