Uncovering Null Effects in Null Fields: The Case of Homeopathy

Sigurdson, Sainani, and Ioannidis (this journal) discussed homeopathy as a prototypical example of a “null field” where true effects are nonexistent and positive effect sizes reflect bias only. Based on a sample of published randomized placebo-controlled trials, they observed a surprisingly large effect in favor of homeopathy (Hedges’ g=0.36 Z g=0.36). In this comment, we propose selective pu blication of significant results as a parsimonious explanation of the overall bias evident in this field.
Source: Journal of Clinical Epidemiology - Category: Epidemiology Authors: Tags: Commentary Source Type: research