Be Careful What You Ask Your Customers - Stanford:
Simonson and Utpal Dholakia of Rice University have also discovered pitfalls in asking customers to compare two or more brands. “Telling consumers to make comparisons, which is a practice that marketers use a lot, can be very uncertain because it can change the behavior of consumers in very fundamental ways,” said Simonson.
Consumers who decided on their own to compare products behaved as you might expect, looking for the best buy. But consumers who were told to compare became unusually cautious. “The mere fact that we had asked them to make a comparison caused them to fear that they were being tricked in some way,” said Simonson.
A seemingly unbiased method of studying consumer preference can nevertheless change behavior. And that calls into question the accuracy—and usefulness—of the opinion survey ...
... Once again, those who voiced expectations in advance were significantly more negative and even rated the same store features such as cleanliness or the professionalism of employees more negatively than the control group.
