Stanovich on science-by-anecdote:

As psychologist Ray Nickerson (1998) has said in his review of the cognitive processes we use to deceive ourselves, "Every practitioner of a form of pseudomedicine can point to a cadre of patients who will testify, in all sincerity, to have benefited from the treatment" (p. 192). For example, subliminal self-help audiotapes... that are purported to raise memory performance or self-esteem generate plenty of testimonials despite the fact that controlled studies indicate that they have absolutely no effect on memory or self-esteem (Moore, 1995).