Collecting data to check for discrimination

Can you process special personal data to check whether an AI system discriminates?

An attribute which is used for discrimination will almost always fall under the special categories of personal data (Art. 8 GDPR). Special categories of personal data may only be processed if you can invoke one of the exceptions to the ban on processing special personal data. One of the exceptions, is that it is permissible to process ethnicity in some cases to implement a temporary preference policy for underrepresented groups. Exception ground g for special categories of personal data has been extended for that in the Dutch implementation act of the GDPR (Uitvoeringswet Algemene verordening gegevensbescherming). It might be possible to have that exception extended to checking whether a model discriminates. Also, explicit consent could be a possible exception ground. Those are the only two options to process special personal data for this purpose GDPR compliant.