In the article “Electrons in the looking glass” (Eric Heller Nature 403, 489–491; 2000), the false impression was given that Madhavan et al. (Science 280, 567–569; 1998) were the first group to publish STM evidence of Kondo resonances. In fact, Li et al. (Phys. Rev. Lett. 80, 2893–2896; 1998) published their results a month earlier. Both groups acknowledge being aware of the other's results before publication.