Plausible-Parrots @ MSP2023: Enhancing Semantic Plausibility Modeling using Entity and Event Knowledge
Chong Shen, Chenyue Zhou
TL;DR
The paper investigates enhancing a large language model with fine-grained entity and event knowledge to improve semantic plausibility judgments for simple events, addressing ambiguities in subject-verb-object and mismatch with natural language inputs. It combines ultra-fine-grained entity typing (UFET), event-type detection, and template-based prompt engineering, augmented by data-balancing techniques and a knowledge base (WikiData) to include definitions. Empirical results show significant gains on the PEP-3K dataset when injecting both event-type and entity-type knowledge, while results on PAP reveal limitations for more abstract phrasing, underscoring the need to handle higher-level abstraction in plausibility modeling. The work demonstrates practical benefits for knowledge-grounded prompting in semantic reasoning tasks and outlines future work on more complex events and multi-modal data.
Abstract
In this work, we investigate the effectiveness of injecting external knowledge to a large language model (LLM) to identify semantic plausibility of simple events. Specifically, we enhance the LLM with fine-grained entity types, event types and their definitions extracted from an external knowledge base. These knowledge are injected into our system via designed templates. We also augment the data to balance the label distribution and adapt the task setting to real world scenarios in which event mentions are expressed as natural language sentences. The experimental results show the effectiveness of the injected knowledge on modeling semantic plausibility of events. An error analysis further emphasizes the importance of identifying non-trivial entity and event types.
