February 15, 2014

I only drink it for the pictures

Stuff has a story about differences in coffee preference between regions of NZ.

A customer survey published yesterday confirms the capital has the country’s biggest coffee snobs – almost three in four will choose an expensive brew over a less tasty one every time.

They don’t give enough information to work out how big the differences are, or how they compare to the uncertainty in the survey.

There’s slightly more information in the press release — still no uncertainty, but we are told that the figure is 72% for Wellington and 67% for the country as a whole. Not a terribly impressive difference, and almost certainly the survey isn’t large enough to be able to tell which region is really highest. Fortunately, it’s not a question where the true answer matters.

You have to go to the Canstar Blue site to find that the survey population isn’t Kiwis in general, or even coffee-drinkers, but people who have been to a chain coffee store at least once in the past six months.

Interestingly, although 17% to 33% of people (varying between regions) consider coffee alone to qualify as breakfast, only 10% to 14% say they drink coffee for the caffeine.

Yeah, right.


Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »