This article provides an overview of the notion of quality in specialized translation according to experts. The author begins with a corpora of 19 texts that include very negative value judgements regarding the translation of specific passages. The purpose was to identify the parameters of translation quality as seen by the group of experts and to systematize them into clear-cut categories. The data gathered from this external viewpoint should serve the ultimate purpose: to create useful and realistic tools for an internal model of professional translation based on one group of users' expectations as to what constitutes a good translation.