A technique used in mentalism and by fraudulent mediums and psychics. You previously know some information and reveal it as you get information for the next answer. Thus, the performer or fraud is always one ahead.
Readers, please enjoy this guest blog post by Sandra Kynes, author of several books, including The Herb Gardener's Essential Guide, Plant Magic, and the new Witches' Encyclopedia of Magical Plants, among many others.
Although a few old books...