According to Marks, when the cues were eliminated the results fell to a chance level. Marks was able to achieve 100 percent accuracy without visiting any of the sites himself but by using cues. James Randi has written that controlled tests by several other researchers, eliminating several sources of cuing and extraneous evidence present in the original tests, produced negative results. Students were also able to solve Puthoff and Targ's locations from the clues that had inadvertently been included in the transcripts.