MoPE: Mixture of Prefix Experts for Zero-Shot Dialogue State Tracking
Tianwen Tang, Tong Zhu, Haodong Liu, Yin Bai, Jia Cheng, Wenliang Chen
TL;DR
This paper tackles zero-shot dialogue state tracking (DST) by addressing domain transfer and partial-prediction failures. It introduces Mixture of Prefix Experts (MoPE), which clusters slots into $K$ groups using $k$-means and assigns a dedicated deep prefix-prompt expert $\\Phi_k$ to each cluster, while keeping the backbone model fixed and training only the prompts. The approach demonstrates notable gains on MultiWOZ2.1 and SGD, achieving an average joint goal accuracy of $57.13\%$ and $55.40\%$, respectively, and shows that specialized prefixes, slot-feature representations, and an appropriate number of clusters are key to success. MoPE provides a parameter-efficient, plug-in solution that improves cross-domain slot transfer and reduces partial-predictions, with practical implications for scalable zero-shot DST in diverse dialog domains.
Abstract
Zero-shot dialogue state tracking (DST) transfers knowledge to unseen domains, reducing the cost of annotating new datasets. Previous zero-shot DST models mainly suffer from domain transferring and partial prediction problems. To address these challenges, we propose Mixture of Prefix Experts (MoPE) to establish connections between similar slots in different domains, which strengthens the model transfer performance in unseen domains. Empirical results demonstrate that MoPE-DST achieves the joint goal accuracy of 57.13% on MultiWOZ2.1 and 55.40% on SGD.
