  Task-oriented dialogue systems have made unprecedented progress with multiple
state-of-the-art (SOTA) models underpinned by a number of publicly available
MultiWOZ datasets. Dialogue state annotations are error-prone, leading to
sub-optimal performance. Various efforts have been put in rectifying the
annotation errors presented in the original MultiWOZ dataset. In this paper, we
introduce MultiWOZ 2.3, in which we differentiate incorrect annotations in
dialogue acts from dialogue states, identifying a lack of co-reference when
publishing the updated dataset. To ensure consistency between dialogue acts and
dialogue states, we implement co-reference features and unify annotations of
dialogue acts and dialogue states. We update the state of the art performance
of natural language understanding and dialogue state tracking on MultiWOZ 2.3,
where the results show significant improvements than on previous versions of
MultiWOZ datasets (2.0-2.2).
