
Augmenting Task-Oriented Dialogue Systems with Relation Extraction
Andrew Lee,1Zhenguo Chen,2Kevin Leach,3Jonathan Kummerfeld 1
1University of Michigan
2Bloomberg
3Vanderbilt University
ajyl@umich.edu, Zhenguo.Chen@colorado.edu, kevin.leach@vanderbilt.edu, jkummerf@umich.edu
Abstract
The standard task-oriented dialogue pipeline uses intent clas-
sification and slot-filling to interpret user utterances. While
this approach can handle a wide range of queries, it does
not extract the information needed to handle more complex
queries that contain relationships between slots. We propose
integration of relation extraction into this pipeline as an effec-
tive way to expand the capabilities of dialogue systems. We
evaluate our approach by using an internal dataset with slot
and relation annotations spanning three domains. Finally, we
show how slot-filling annotation schemes can be simplified
once the expressive power of relation annotations is available,
reducing the number of slots while still capturing the user’s
intended meaning.
1 Introduction
Dialogue platforms like Watson, Rasa, and Dialogflow have
enabled a dramatic increase in the development and use of
dialogue systems by bringing together NLP models, data
collection and curation, and scalable deployment (Meteer
et al. 2019). These platforms all follow the same general
framework for interpreting queries, shown in Figure 1, con-
sisting of (1) classification models for domain or intent iden-
tification and (2) slot-filling or entity recognition models to
identify relevant entities in a query. While these two models
can handle a wide range of queries, they are unable to handle
more complex queries (Aghajanyan et al. 2020; Davidson,
Yu, and Yu 2019; Gupta et al. 2018). Specifically, when a
query contains multiple slots with semantic relations, such
as those shown in Table 1, intent classification and slot-
filling cannot easily capture the necessary information.
Meanwhile, Relation Extraction (RE) has been effectively
applied to a range of data sources, such as news articles,
encyclopedia entries, and blog posts, and even conversa-
tional data (Yu et al. 2020). Recently, conversational seman-
tic parsing (Aghajanyan et al. 2020; Cheng et al. 2020; An-
dreas et al. 2020) has also built large end-to-end models to
extract semantic relations. While these representations are
expressive, they have not been integrated into dialogue sys-
tem platforms because of the difficulty of collecting new
domain-specific data.
Copyright © 2022, Association for the Advancement of Artificial
Intelligence (www.aaai.org). All rights reserved.
NLU Module
ASR Domain/
Intent
Identification
Slot Filling Relation
Extraction
Dialogue
Management
Backend
Application
Natural
Language
Generation
TTS
User
Figure 1: The standard architecture of deployed dialogue
systems. We show how adding relation extraction can enable
support for more complex queries.
In this paper, we show how relation extraction can be
incorporated into task-oriented dialogue systems. RE is
a lightweight but powerful way to extend the capabili-
ties of a dialogue system. In particular, suitable data can
be rapidly annotated without extensive training, making
domain-specific development feasible.
To evaluate our idea, we use an internal conversational
dataset spanning three domains containing multiple slots
and relations. We investigate the accuracy, scalability, and
generalizability of a relation extraction model within a di-
alogue system. Finally we demonstrate the benefits of in-
cluding an RE model in terms of the dialogue system’s
expressive power, meaning the system’s ability to derive
new semantic information that was not seen during train-
ing. Adding relation extraction to the task-oriented dialogue
pipeline will broaden the range of queries these systems can
handle and improve their robustness to variation in the ways
people express relations in their queries.
2 Related Work
We give a brief overview in various ways in which semantic
relations can be extracted in a dialogue setting.
2.1 Relation Extraction
Relation Extraction (RE) models predict labeled links be-
tween spans of text. They have been incorporated into
a range of downstream applications, including question-
answering, ontology population, and knowledge base con-
struction. These have involved applying RE at a range of
arXiv:2210.13344v1 [cs.CL] 24 Oct 2022