While the experimenter and one confederate knew that the second subject was role-playing, nobody else knew this. The subject was instructed to maintain the role at all times once the instruction was given, even when alone with the experimenter or when taking a test, until the instruction was removed. At the end of the experimental series, the outside observer, whose job it was to conduct a separate, independent clinical diagnostic interview and describe the behavior he observed, was told that one of the two subjects had been simulating. After expressing surprise, he chose the hypnotized subject as being the simulator, on the grounds that the behavior of the simulator had seemed more natural.