The Austrian medium Rudi Schneider was investigated in 1924 by the physicists Stefan Meyer and Karl Przibram. They caught Rudi freeing his arm in a series of séances. Rudi claimed he could levitate objects but according to Harry Price a photograph taken on April 28, 1932 showed that Rudi had managed to free his arm to move a handkerchief from the table. According to Warren Jay Vinton, Schneider was an expert at freeing himself from control in the séance room. Oliver Gatty and Theodore Besterman who tested Schneider concluded that in their tests there was "no good evidence that Rudi Schneider possesses supernormal powers."
An experiment conducted by the British Psychological Society in 2005 suggests that under the controlled condition of the experiment, people who claimed to be professional mediums do not demonstrate the mediumistic ability. In the experiment, mediums were assigned to work the participants chosen to be "sitters." The mediums claimed to contact the deceased who were related to the sitters. The research gather the numbers of the statements made and have the sitters rate the accuracy of the statements. The readings that were considered to be somewhat accurate by the sitters were very generalized, and the ones that were considered inaccurate were the ones that were very specific.
"Mental mediumship" is communication of spirits with a medium by telepathy. The medium mentally "hears" (clairaudience), "sees" (clairvoyance), and/or feels (clairsentience) messages from spirits. Directly or with the help of a spirit guide, the medium passes the information on to the message's recipient(s). When a medium is doing a "reading" for a particular person, that person is known as the "sitter".
The exposures of fraudulent activity led to a rapid decline in ectoplasm and materialization séances. Investigator Joe Nickell has written that modern self-proclaimed mediums like John Edward, Sylvia Browne, Rosemary Altea and James Van Praagh are avoiding the Victorian tradition of dark rooms, spirit handwriting and flying tambourines as these methods risk exposure. They instead use "mental mediumship" tactics like cold reading or gleaning information from sitters before hand (hot reading). Group readings also improve hits by making general statements with conviction, which will fit at least one person in the audience. Shows are carefully edited before airing to show only what appears to be hits and removing anything that does not reflect well on the medium.
^ "Glossary of Key Words Frequently Used in Parapsychology" Archived 2010-12-24 at the Wayback Machine, Parapsychological Association website. "Materialization: A phenomenon of physical mediumship in which living entities or inanimate objects are caused to take form, sometimes from ectoplasm." Retrieved January 24, 2006 "Medium – Definition". Dictionary.com. Retrieved 23 March 2007.