People spend a lot of money on bottled water. But do they really prefer bottled water to ordinary tap water? Researchers at Longwood University (Lunsford and Dowling Fink,
2010) investigated this question by presenting people who came to a booth at a local
festival with four cups of water. Three cups contained different brands of bottled water,
and one cup was filled with tap water. Each subject (person) was asked which of the four
cups of water they most preferred. Researchers kept track of how many people chose tap
water in order to see whether tap water was chosen significantly less often than would
be expected by random chance.