Learning to Use ESP: Do the Calls Match the Targets or Do the Targets Match the Calls

An experiment reported by Charles T. Tart as providing evidence that subjects can learn to use ESP is examined for the possibility that the highly significant scoring rates could be due to factors other than ESP by the subjects. Since the procedure involved a screening of experimenters as well as subjects and the highly significant results were obtained by only one experimenter, it is likely that the screening procedure actually served to select a successful experimenter. Analyses were carried out to investigate the possibility that the results could be due, at least in part, to an influence upon the targets such that they matched the subjects' calls. Significant results were found in support of this hypothesis. Determining the mechanism that was dominant in the production of the highly significant overall results for this experimenter will probably be difficult, but hypotheses other than ESP by the subjects must be considered. Several weaknesses in the design of the experiment are discussed so that they can be avoided in follow-