In scientific research, including parapsychology, a procedure wherein neither the subject nor even the experimenter is aware of valuable key aspects of the experiment. For example, one experimenter could put a variety of photos in separate envelopes. A second experimenter would randomly choose one of the envelopes and could not have any idea of what is in the envelope. The subject would try to determine, paranormally, what is in the envelope.
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...