NARRATIVE REASONING BY GROUNDING TO EVENT-CENTRIC KNOWLEDGE GRAPHS

The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


MPhil Thesis Defence


Title: "NARRATIVE REASONING BY GROUNDING TO EVENT-CENTRIC KNOWLEDGE GRAPHS"

By

Mr. Jiayang CHENG


Abstract:

Narrative reasoning relies on the understanding of events in story contexts,
which requires abundant background world knowledge. To help machines leverage
such knowledge, existing solutions fall into two categories. Some focus on
implicitly modeling event knowledge by pretraining language models (LMs) with
event-aware objectives, which breaks down knowledge structures and suffers from
poor interpretability. Others explicitly collect world knowledge of events into
structured event-centric knowledge graphs (KGs). However, existing research on
leveraging these knowledge sources for free-texts is largely absent. In this
thesis, we propose an initial comprehensive framework, Even- Ground, to tackle
the problem of grounding1 free-texts to event-centric KGs for contextualized
narrative reasoning. We point out two critical problems on this direction,
namely the event representation and sparsity problems, and address them by
simple while effective parsing and abstraction methods. Experimental results on
several representative narrative reasoning tasks show that our approach
consistently outperforms baseline models and achieves new state-of-the-art
performance, while providing human-interpretable evidence.


Date:                   Tuesday, 1 August 2023

Time:                   10:00am - 12:00noon

Venue:                  Room 3494
                        lifts 25/26

Committee Members:      Dr. Yangqiu Song (Supervisor)
                        Prof. Raymond Wong (Chairperson)
                        Dr. Dan Xu


**** ALL are Welcome ****