  Users of AI systems may rely upon them to produce plans for achieving desired
objectives. Such AI systems should be able to compute obfuscated plans whose
execution in adversarial situations protects privacy, as well as legible plans
which are easy for team members to understand in cooperative situations. We
develop a unified framework that addresses these dual problems by computing
plans with a desired level of comprehensibility from the point of view of a
partially informed observer. For adversarial settings, our approach produces
obfuscated plans with observations that are consistent with at least k goals
from a set of decoy goals. By slightly varying our framework, we present an
approach for goal legibility in cooperative settings which produces plans that
achieve a goal while being consistent with at most j goals from a set of
confounding goals. In addition, we show how the observability of the observer
can be controlled to either obfuscate or clarify the next actions in a plan
when the goal is known to the observer. We present theoretical results on the
complexity analysis of our problems. We demonstrate the execution of obfuscated
and legible plans in a cooking domain using a physical robot Fetch. We also
provide an empirical evaluation to show the feasibility and usefulness of our
approaches using IPC domains.
