A widely known channeler of this variety is J. Z. Knight, who claims to channel the spirit of Ramtha, a 30 thousand-year-old man. Others purport to channel spirits from "future dimensions", ascended masters, or, in the case of the trance mediums of the Brahma Kumaris, God. Other notable channels are Jane Roberts for Seth, Esther Hicks for Abraham, and Carla L. Rueckert for Ra.
Usually the reader can tell what tool would be best on a specific client in order to gain the most information. Some clients believe they should dictate that. Usually the reader knows based on their connection to the client. All tools have their limits. For this reason having more tools helps the reader develop wholeness. There are times when just the day itself can have its own energy. Perhaps the reader channeled a lot within the day and a different tool can be used to refresh the reader. There are some readers that can only channel during certain hours of the day.
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. 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. 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.