Probably in the top two
From Sophie Jones on Twitter:
If you zoom in on the fine print, that’s 50.6% of 15096 people preferring Pepsi Max over full-sugar Coca-Cola. You could quibble about the comparison — should this be restricted to cola drinkers (or non-cola drinkers); what happened to the diet versions; how about L&P? — but it’s a comparison.
More obviously, 50.6% is very close to 50%. You might ask what the margin of error was for a sample of 15000. It’s more than 0.6%: these results are consistent with just a coin toss. It might taste like victory, but only if victory doesn’t taste very distinctive.
On the other hand, Pepsi lost the cola wars in New Zealand, so the starting point might reasonably not be 50:50. This survey doesn’t convincingly show that Pepsi Max is preferred over Coca-Cola by a majority even in blind two-way comparisons, but it does show it’s not far behind. And, in context, that’s probably worth advertising.
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 »