Prompt Learning for Few-Shot Dialogue State Tracking

Collecting dialogue state labels, slots and values, for learning dialogue state tracking (DST) models can be costly, especially with the wide application of dialogue systems in new-rising domains. In this paper, we focus on how to learn a DST model efficiently with limited labeled data. We design a prompt learning framework for few-shot DST, which consists of two main components: value-based prompt and inverse prompt mechanism. This framework aims to utilize the language understanding and generation ability of pre-trained language models (PLM). First, we design value-based prompt functions to probe the DST-related knowledge from PLM, which do not rely on the known ontology of slots. Further, an inverse prompt mechanism is utilized to self-check the "prompted" knowledge and help the PLM understand the essence of DST task further. Experiments show that our model can generate unseen slots and outperforms existing state-of-the-art few-shot methods. It indicates that DST-related knowledge can be probed from PLM and utilized to address low-resource DST efficiently with the help of prompt learning.