Research Paper: Individual and Joint Expert Judgments as Reference Standards in Artifact Detection. - Marion Verduijn; Niels Peek; Nicolette de Keizer; Erik-Jan van Lieshout; Anne-Cornelie J. M. de Pont; Marcus J. Schultz; Evert de Jonge; Bas A. de Mol (J. Am. Medical Informatics Assoc., 2008)