  In this short paper, we consider the roles of HCI in enabling the better
governance of consequential machine learning systems using the rights and
obligations laid out in the recent 2016 EU General Data Protection Regulation
(GDPR)---a law which involves heavy interaction with people and systems.
Focussing on those areas that relate to algorithmic systems in society, we
propose roles for HCI in legal contexts in relation to fairness, bias and
discrimination; data protection by design; data protection impact assessments;
transparency and explanations; the mitigation and understanding of automation
bias; and the communication of envisaged consequences of processing.
