Stephen Barrett of Quackwatch defines quackery "as the promotion of unsubstantiated methods that lack a scientifically plausible rationale" and more broadly as: "anything involving overpromotion in the field of health."
Stephen Barrett fra Quackwatch definerer kvaksalveri som "promoveringen af udokumenterede metoder der mangler videnskabeligt plausibelt rationale" og mere bredt som: "enhver ting der involverer overpromovering inden for sundhedsområdet."