Markwick, and the Case for Keeping the Original Sheets

Suspicion had circulated for years, including a claim by one witness that she had seen Soal altering figures, which he denied and which could not be substantiated. What settled the matter was arithmetic on the surviving records. Betty Markwick, working in the 1970s, set out to test whether Soal had generated his target sequences by the method he described, and searched the sheets for repeated runs of digits. She found them, and she found something more damaging: where a sequence recurred, it recurred with extra digits inserted, and the inserted digits fell overwhelmingly at the positions where Shackleton had been credited with a hit. That is not a pattern any honest procedure produces. Her paper appeared in 1978 in the Proceedings of the Society for Psychical Research, the same body that had published and defended the original work, and the field accepted the conclusion.

Two things about this episode deserve emphasis. The exposure came from inside parapsychology and was published by it, which is a point in the field's favour and is rarely credited. And it was only possible because the original score sheets had been kept, thirty-five years after the sessions. A summary statistic cannot be audited this way, and this case is the standing argument for archiving raw data.