HyKnow: End-to-End Task-Oriented Dialog Modeling with Hybrid Knowledge Management

TL;DR

HyKnow is an end-to-end task-oriented dialog system that effectively manages both structured and unstructured knowledge, improving dialog accuracy and knowledge retrieval over existing methods.

Contribution

This paper introduces HyKnow, the first end-to-end TOD model that jointly optimizes dialog management with hybrid knowledge handling, including unstructured data.

Findings

HyKnow outperforms existing TOD systems in end-to-end tasks.

It achieves higher unstructured knowledge retrieval accuracy.

Demonstrates effectiveness on a modified MultiWOZ 2.1 dataset.

Abstract

Task-oriented dialog (TOD) systems typically manage structured knowledge (e.g. ontologies and databases) to guide the goal-oriented conversations. However, they fall short of handling dialog turns grounded on unstructured knowledge (e.g. reviews and documents). In this paper, we formulate a task of modeling TOD grounded on both structured and unstructured knowledge. To address this task, we propose a TOD system with hybrid knowledge management, HyKnow. It extends the belief state to manage both structured and unstructured knowledge, and is the first end-to-end model that jointly optimizes dialog modeling grounded on these two kinds of knowledge. We conduct experiments on the modified version of MultiWOZ 2.1 dataset, where dialogs are grounded on hybrid knowledge. Experimental results show that HyKnow has strong end-to-end performance compared to existing TOD systems. It also outperforms the pipeline knowledge management schemes, with higher unstructured knowledge retrieval accuracy.