In 1917, Edward Clodd analyzed the mediumship of the trance medium Gladys Osborne Leonard and came to the conclusion that Leonard had known her séance sitters before she had held the séances, and could have easily obtained such information by natural means.[119] The British psychiatrist Charles Arthur Mercier wrote in his book Spiritualism and Sir Oliver Lodge (1917) that Oliver Lodge had been duped into believing mediumship by trickery and his spiritualist views were based on assumptions and not scientific evidence.[120] https://drive.google.com/file/d/1LebjUFtNBfTFfNkHrRdXaYsh6DfGnxvi/view?usp=sharing
The exposures of fraudulent activity led to a rapid decline in ectoplasm and materialization séances.[202] 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.[203] https://drive.google.com/file/d/1m8tDdnDvQeYKNhkzNnvJxqGwwuFGxT1C/view?usp=sharing
The suffix Voyant in Clairvoyant does not necessarily imply seeing pictures, graphics or pictorial presentation as such. ‘Seeing’ may also mean  ‘understanding’ like in ‘Oh, I see!’ In this context the ability of the clairvoyant medium may also include clairsentience, which means that the clairvoyant medium clearly senses the things and the situations. He experiences a kind of gut feeling about what is going to happen or how a situation can be best tackled to provide good results. https://drive.google.com/file/d/1F-Dbl7jUcRo6ni-O3q1IgUdOkJN-kDM7/view?usp=sharing
^ "Spiritism is not a religion but a science", as the famous French astronomer Camille Flammarion said in Allan Kardec's Eulogy on April 2, 1869, in Death and Its Mystery – After Death. Manifestations and Apparitions of the Dead; The Soul After Death Translated by Latrobe Carroll (London: Adelphi Terrace, 1923), archive version at Allan Kardec eulogy
In a 2019 television segment on Last Week Tonight featuring prominent purported mediums including Theresa Caputo, John Edward, Tyler Henry, and Sylvia Browne, John Oliver criticized the media for promoting mediums because this exposure convinces viewers that such powers are real, and so enable neighborhood mediums to prey on grieving families. Oliver said "...when psychic abilities are presented as authentic, it emboldens a vast underworld of unscrupulous vultures, more than happy to make money by offering an open line to the afterlife, as well as many other bullshit services."[52][53][54]

In 1880 the American stage mentalist Washington Irving Bishop published a book revealing how mediums would use secret codes as the trick for their clairvoyant readings.[87] The Seybert Commission was a group of faculty at the University of Pennsylvania who in 1884–1887 exposed fraudulent mediums such as Pierre L. O. A. Keeler and Henry Slade.[88] The Fox sisters confessed to fraud in 1888. Margaret Fox revealed that she and her sister had produced the "spirit" rappings by cracking their toe joints.[89]


The fraudulent medium Ronald Edwin confessed he had duped his séance sitters and revealed the fraudulent methods he had used in his book Clock Without Hands (1955).[167] The psychical researcher Tony Cornell investigated the mediumship of Alec Harris in 1955. During the séance "spirit" materializations emerged from a cabinet and walked around the room. Cornell wrote that a stomach rumble, nicotine smelling breath and a pulse gave it away that all the spirit figures were in fact Harris and that he had dressed up as each one behind the cabinet.[168]
The Polish medium Stanisława Tomczyk's levitation of a glass beaker was exposed and replicated in 1910 by the magician William S. Marriott by means of a hidden thread.[117] The Italian medium Lucia Sordi was exposed in 1911, she was bound to a chair by psychical researchers but would free herself during her séances. The tricks of another Italian medium Linda Gazzera were revealed in the same year, she would release her hands and feet from control in her séances and use them. Gazzera would not permit anyone to search her before a séance sitting, as she concealed muslin and other objects in her hair.[118] https://drive.google.com/file/d/15C7azc9N5Rtx8lwGMfSsZVrEmzKBYKsG/view?usp=sharing
The fraudulent medium Ronald Edwin confessed he had duped his séance sitters and revealed the fraudulent methods he had used in his book Clock Without Hands (1955).[167] The psychical researcher Tony Cornell investigated the mediumship of Alec Harris in 1955. During the séance "spirit" materializations emerged from a cabinet and walked around the room. Cornell wrote that a stomach rumble, nicotine smelling breath and a pulse gave it away that all the spirit figures were in fact Harris and that he had dressed up as each one behind the cabinet.[168]
^ "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.