Two Buildings, One Clock, and a Sealed Record

The arrangement was simple enough to describe in a sentence and that is the point of it. J. Gaither Pratt sat in the Social Sciences building with a shuffled deck and turned one card face down at each minute by an agreed clock. Hubert Pearce sat in the campus library, a hundred yards or more away with buildings between, wrote his call for each minute, and sealed his record. Pratt sealed his own list of the actual order. Neither man saw the other's record until both were opened in front of J. B. Rhine.

The design removes several things at once. There is no experimenter in the room to signal, deliberately or otherwise. There is no possibility of the subject seeing a card, since the cards were face down in another building. There is no opportunity to adjust either record afterwards, because both were sealed before either was read. Across the subseries the investigators reported 558 hits in 1,850 trials against a chance expectation of 370. Those figures are the investigators' own and have never been shown to be miscounted; what is disputed is whether the arrangement was as sealed as the description makes it sound. The precaution of sealing both records before either was opened is the part most often left out of secondhand accounts, and it is the part that makes the design worth arguing about at all.