A case study investigation was undertaken to identify threats to the professional understanding of assessment error which arise from accounts presented within the education press. Through a predominantly qualitative analysis of articles published in a leading education newspaper, during 2002 and 2003, it explored how assessment agencies in England were represented as responding to allegations of error. A number of threats to professional understanding were identified; in particular, the overarching threat that media reports may help to construct, and to maintain, a mythical image of assessment as a process which can and ought to be free from both measurement inaccuracy and human error. The results highlighted an underlying tension between the need to increase public understanding (of assessment error) and the need to retain public confidence (in our assessment systems). It was concluded that assessment agencies need to develop approaches to enhancing the public and professional understanding of assessment error, to counteract potentially misleading images from media reports.