1. A user terminal device comprising means for extracting artefact features from media data, Means for transmitting the extracted features to a server device, Means for receiving quality scores for the media data from the server device, Means for presenting a received quality score to a user, and Means for receiving, from the user, a subjective quality score and a request for re-determining the quality score wherein the means for transmitting is adapted for communicating the request for re-determining the quality score and the subjective quality score to the server device.