The book test is a way for the deceased to communicate with the living and provide evidence of their survival after death. It was developed in the early twentieth century by English medium Gladys Osborne Leonard and her spirit control, Freda.

In the book test the deceased communicates through a medium and provides the title of a book not known to the medium. The deceased gives the book’s exact location and then specifies a page number, which is supposed to contain a message from the deceased. Leonard’s book tests were very successful, and almost always the passage selected contained personal messages.

Book tests were very popular around the time of World War I, when interest in communicating with the dead was strong, but not all book tests were as successful as Leonard’s. A study published in 1921 suggested that only around 17 per cent were successful.

Paranormal factors may well figure in some book tests, but this does not necessarily imply that there is life after death, as book tests can be easily explained by the idea that the medium him or herself is picking up psychic information. Another problem with book tests as proof of life after death is that on almost any page of a given book some passage may be interpreted as a message.