  With Artificial intelligence (AI) to aid or automate decision-making
advancing rapidly, a particular concern is its fairness. In order to create
reliable, safe and trustworthy systems through human-centred artificial
intelligence (HCAI) design, recent efforts have produced user interfaces (UIs)
for AI experts to investigate the fairness of AI models. In this work, we
provide a design space exploration that supports not only data scientists but
also domain experts to investigate AI fairness. Using loan applications as an
example, we held a series of workshops with loan officers and data scientists
to elicit their requirements. We instantiated these requirements into FairHIL,
a UI to support human-in-the-loop fairness investigations, and describe how
this UI could be generalized to other use cases. We evaluated FairHIL through a
think-aloud user study. Our work contributes better designs to investigate an
AI model's fairness-and move closer towards responsible AI.
