Some scientists of the period who investigated spiritualism also became converts. They included chemist Robert Hare, physicist William Crookes (1832–1919) and evolutionary biologist Alfred Russel Wallace (1823–1913). Nobel laureate Pierre Curie took a very serious scientific interest in the work of medium Eusapia Palladino. Other prominent adherents included journalist and pacifist William T. Stead (1849–1912) and physician and author Arthur Conan Doyle (1859–1930).
In 1970 two psychical researchers investigated the direct-voice medium Leslie Flint and found that all the "spirit" voices in his séance sounded exactly like himself and attributed his mediumship to "second-rate ventriloquism". The medium Arthur Ford died leaving specific instructions that all of his files should be burned. In 1971 after his death, psychical researchers discovered his files but instead of burning them they were examined and discovered to be filled with obituaries, newspaper articles and other information, which enabled Ford to research his séance sitters backgrounds.
In 1991, Wendy Grossman in the New Scientist criticized the parapsychologist Stephen E. Braude for ignoring evidence of fraud in mediumship. According to Grossman "[Braude] accuses sceptics of ignoring the evidence he believes is solid, but himself ignores evidence that does not suit him. If a medium was caught cheating on some occasions, he says, the rest of that medium's phenomena were still genuine." Grossman came to the conclusion that Braude did not do proper research on the subject and should study "the art of conjuring."
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.