In supplement 1 this year, October 2004, the paper by J B Cooper and V R Taqueti (A brief history of the development of mannequin simulators for clinical education and training. Qual Saf Health Care 2004;13:i11–i18) was missing an acknowledgement, which follows: The authors thank Drs Richard Satava, Steve Dawson, Dwight Meglan, and John Schaefer for providing historical information and insights for this article.