  Dialogue state tracking (DST) is a component of the task-oriented dialogue
system. It is responsible for extracting and managing slot values according to
dialogue utterances, where each slot represents an essential part of the
information to accomplish a task, and slot value is updated recurrently in each
dialogue turn. However, many DST models cannot update slot values
appropriately. These models may repeatedly inherit wrong slot values extracted
in previous turns, resulting in the fail of the entire DST task. They cannot
update indirectly mentioned slots well, either. This study designed a model
with a mentioned slot pool (MSP) to tackle the update problem. The MSP is a
slot-specific memory that records all mentioned slot values that may be
inherited, and our model updates slot values according to the MSP and the
dialogue context. Our model rejects inheriting the previous slot value when it
predicates the value is wrong. Then, it re-extracts the slot value from the
current dialogue context. As the contextual information accumulates with the
dialogue progress, the new value is more likely to be correct. It also can
track the indirectly mentioned slot by picking a value from the MSP.
Experimental results showed our model reached state-of-the-art DST performance
on MultiWOZ 2.1 and 2.2 datasets.
