I prefer Coke but never mind.

And so the tricky question was asked: "Michael, do you prefer New Coke or regular Coke?"

The computer had asked Dairine whether she preferred Coke or Pepsi, and had then fallen silent for some seconds.

The outcome was remarkable: almost all the subjects said they preferred Coke.

With comparative scaling, the items are directly compared with each other (example : Do you prefer Pepsi or Coke?)

Pairwise comparison scale - a respondent is presented with two items at a time and asked to select one (example : Do you prefer Pepsi or Coke?)

Getting the math problems right predicts nothing about most tastes, including whether someone prefers apples or oranges, Coke or Pepsi, rap music or ballet.

Consumers who prefer Coke to Pepsi, for example, will not trade between them in a one-to-one fashion.

Then the representative reveals the two bottles so the taster can see whether they preferred Coke or Pepsi.