Osis and Haraldsson’s (1977) study was based on replies received from ten thousand questionnaires sent to doctors and nurses in the United States and India. Only 6.4 percent were returned. Since it was the doctors and nurses who were giving the reports, not the patients who had, presumably, actually had the experience, the reports were secondhand. This means they had passed through two highly fallible and constructive human memory systems (the doctor’s or nurse’s and the actual patient’s) before reaching Osis and Haraldsson.