Am I Building a White Box Agent or Interpreting a Black Box Agent?

The rule extraction literature contains the notion of a fidelity-accuracy dilemma: when building an interpretable model of a black box function, optimising for fidelity is likely to reduce performance on the underlying task, and vice versa. We reassert the relevance of this dilemma for the modern field of explainable artificial intelligence, and highlight how it is compounded when the black box is an agent interacting with a dynamic environment. We then discuss two independent research directions – building white box agents and interpreting black box agents – which are both coherent and worthy of attention, but must not be conflated by researchers embarking on projects in the domain of agent interpretability.