The Magician Who Went into the Data

Wiseman occupies an unusual position: trained as a conjuror before he was trained as a psychologist, he has done most of his critical work not by exposing tricks but by re-analysing published literature. The 1999 meta-analysis he published with Julie Milton is the clearest example. Taking thirty ganzfeld studies conducted after the autoganzfeld series that Charles Honorton had reported, they found no significant overall effect, which was the first substantial answer to the claim that the protocol had become reliably replicable. Proponents responded that the sample included studies departing from the standard protocol and that a later pooling by Storm, Tressoldi and Di Risio in 2010, covering 1992 to 2008, did find an effect; the disagreement is about which studies belong in the pool, and it has not been settled.

In 2012 Wiseman published, with Stuart Ritchie and Christopher French, three failed direct replications of Daryl Bem's retroactive recall experiments, and the group's difficulty in placing a null result became a case study in the publication-bias reforms that followed. What distinguishes this body of work from ordinary debunking is that it is conducted in the currency the field itself uses. A meta-analysis can be answered with another meta-analysis, and it has been, repeatedly, which is why the ganzfeld argument has stayed alive rather than ending in mutual dismissal.