8 pseudopatients phoned hospitals for an appointment to gain admission and once they arrived at the admissions office they complained they had been hearing voices. The voice was unfamiliar and the same sex as themselves, it was often unclear but they could hear it say 'empty', 'hollow' and 'thud'.
Once they were admitted, they immediately acted normally with no mention of the symptoms again. The fake patient would act and speak like he or she normally would, they did everything they were asked such as going to dinner, but didnt take any medication. While on the ward they made noted on what happened, often in public places. They were only allowed to leave if they were discharged.
Each pseudopatient (apart from 1) was admitted with a diagnosis of schizophrenia in remission. They were never detected for being fake by medical staff and records show this. The time they spent in the hospital ranged from 7 to 52 day, with an average of 19 days. Other patients were fooled as easily as 35 out of 118 patients voiced their suspicions about the 'insanity' of pseudopatients saying things like 'you're not crazy'.
Rosenhan did a 2nd experiment, the staff at the hospitals doubted rosenhans finding and were certain they would identify pseudopatients, so he tested this. The staff were told that 1 or more pseudopatients would attempt to be admitted during a 3 month period into their hospital. Their job was to find these patients and did this on a scale 1-10.
At least one staff member rated 41 patients as highly confident they were pseudopatients 23 were rated highly confident by at least one pseudopatients. However, Rosenever admitted any 'normal' people at all, all the patients in the hospital were genuine.