and could conceive of no means by which the results could be obtained by normal means other than ESP. Many leading academics, including C. D. Broad and Sir Cyril Burt, were persuaded, largely or partly on the basis of these reports, to lend academic support to psi-related ideas and research. Arguments against Soal's data have, however, been raised ever since their publication. These proposed "unconscious whispering" (from the experimenter to the ‘agent,’ and then from the ‘agent’ to the ‘percipient’); the inapplicability of probability theory to science (as offered by George Spencer-Brown); and collusion between the ‘agent’ to the ‘percipient’. Outright fraud was also advanced (by George R. Price) and prominently canvassed in the American journal Science. Soal attempted to rebut the critiques. In 1978, it was reported that Soal evidently appeared to reuse some target sequences from an earlier test in a later one, often reversing, omitting or inserting one or more digits into the sequence before reusing them. It was considered suspicious that a disproportionate number of "hits" occurred on the digits that appeared to interrupt some of the reused sequences. Betty Marwick discovered that Soal had not used the method of random selection of numbers as he had claimed. Marwick showed that there had been manipulation of the score sheets "all the experiments reported by Soal had thereby been discredited." For two of the 40 sessions with Shackleton, it was claimed that it was "virtually conclusive" that this practice amounted to fraud; and fraud in another six sessions was considered to be "suggestive only". Soal was not able to replicate his earlier work while continuing to conduct telepathy experiments, at the University of London, after his retirement, from 1954 to 1958. During these years, however, he conducted a long series of apparently successful experiments with a pair of young brothers, as participants, in Northern Wales. This work was immediately and severely criticised on methodological grounds; simulations of the study suggesting that the boys, with their family, could have been successfully undetected in using a code in association with an ultrasonic whistle, perhaps blown by a secreted pump. It was not until the 1970s, when Soal was already senile and no longer able to respond, that his data were finally deemed insupportable by his fellow parapsychologists. These concerned largely statistical challenges offered by members of the SPR on the basis of several novel analyses they conducted by computer