People in the grocery store are asked to do a taste test of a new soft drink product. Two paper cups are given to each person who volunteers. Fifty percent of the participants are given two different soft drinks. The other half receive the same product, but are told the drinks are different. Those who report that they taste a difference between the drinks, when they are exactly the same are:

Question

demonstrating a placebo effect.
involved in a double-blind study.
participating in a single-blind study, the same as the other half.
demonstrating the results of experimenter effects.
This is making me scratch my head, but I opted for D.

Answer 1

I believe that it's A.

Answer 2

I second Jen's response.

http://en.wikipedia.org/wiki/Placebo