As we have seen, this is not the case here, because most records either lack this information or provide it in an inconsistent manner. This means that for the purpose of digital investigations of these data, the role of <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">praeses</hi> and <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">respondens</hi> cannot be analysed with the required degree of representativity: if less than half of the records in one dataset and about 80% of records in the second dataset do not provide reliable information about these roles, even the information we have is of no value, because we cannot be sure to which extent the records that do contain this information are representative for the dataset as a whole. In other words, the existing data about the authorial roles of <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">praeses</hi> and <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">respondens</hi> are unusable not because they may not be accurate, but because the corresponding UNIMARC relators are applied in an inconsistent manner: if in some cases a <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">praeses</hi> appears as ‘thesis advisor’ in the record, although he was in fact the main author of the text, this misattribution is inaccurate with regard to the individual work. But if the role of ‘thesis advisor’ for the <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic"> praeses </hi>were applied consistently across all available data, we could translate it back into the category ‘ <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">praeses</hi>’ without caring about the correctness or incorrectness of this modern attribution in some cases: consistency trumps accuracy.