In 1973 Rosenhan published "On Being Sane in Insane Places". This was one of the most-read pieces of writing in psychology. The article talks about the Rosenhan experiment. The experiment was that eight people with no history of psychopathology would try to get into twelve psychiatric hospitals. All of these people were allowed in, and were diagnosed with either schizophrenia or bipolar disorder. Psychiatrists then tried to cure the people using psychiatric medicines. All eight were allowed to leave within 7 to 52 days, but only when they had said that they accepted the illness they had been diagnosed with. Later in the study, a research and teaching hospital challenged Rosenhan to run a similar experiment with its own diagnoses and rules for letting people in to the hospital. Psychiatric staff were warned that at least one pseudo-patient might be sent to their hospital. At least one staff member thought that 83 out of the 193 new patients were actors. In fact, Rosenhan sent no actors. The study showed that the ways diagnosis was done was very inaccurate in telling people with mental disorders and people without mental disorders apart. The paper made a lot of controversy. Some people are not sure of how valid and credible the study was, but say that psychiatric diagnoses need to be improved.