  We present NormBank, a knowledge bank of 155k situational norms. This
resource is designed to ground flexible normative reasoning for interactive,
assistive, and collaborative AI systems. Unlike prior commonsense resources,
NormBank grounds each inference within a multivalent sociocultural frame, which
includes the setting (e.g., restaurant), the agents' contingent roles (waiter,
customer), their attributes (age, gender), and other physical, social, and
cultural constraints (e.g., the temperature or the country of operation). In
total, NormBank contains 63k unique constraints from a taxonomy that we
introduce and iteratively refine here. Constraints then apply in different
combinations to frame social norms. Under these manipulations, norms are
non-monotonic - one can cancel an inference by updating its frame even
slightly. Still, we find evidence that neural models can help reliably extend
the scope and coverage of NormBank. We further demonstrate the utility of this
resource with a series of transfer experiments.
