Is meta-analysis all just ‘an exercise in mega-silliness’?
To my mind, there was something heroic about Gene Glass’ presidential address to the 1976 American Educational Research Association annual meeting. Prior to this, and dismayed by attacks on psychotherapy by psychologist Hans Eysenck, Glass and his colleague Mary Lee Smith manually searched over a thousand papers on the subject, identifying 375 to be suitable for their investigation into the effects of psychotherapy.
Working with often incomplete information from a multiplicity of sources, Glass applied his innovative statistical mind and, using a technique we now know as ‘meta-analysis’, found a sizeable treatment effect of psychotherapy; a result which has been confirmed by other researchers subsequently, but one derided at the time as ‘An Exercise in Mega-Silliness’ in a 1978 American Psychologist article written by the aforementioned Eysenck. Glass took a stand in San Francisco in 1976, and 43 years later the debate continues 5,000 miles away in Durham, UK.