Precognition is the hardest aspect of parapsychology for us to understand yet the easiest to experience and to test scientifically in the laboratory. Retrocognition occurs but is reported much more rarely. Hundreds of studies have been made of spontaneous precognition expe­riences and of controlled experiments in the laboratory. The use of modern electronic instruments has confirmed this. Even dreams have been shown to come true in the laboratory. This essay, chapter 6 from Psychic Exploration, studies precognition and retrocognition. The full volume of Psychic Exploration can be purchased as an ebook or paperback version from all major online retailers and at cosimobooks.com.