Entity or Relation Embeddings? An Analysis of Encoding Strategies for Relation Extraction

Fuente: arXiv
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Autori principali: Mtumbuka, Frank, Schockaert, Steven
Natura: Preprint
Pubblicazione: 2023
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author Mtumbuka, Frank
Schockaert, Steven
author_facet Mtumbuka, Frank
Schockaert, Steven
contents Relation extraction is essentially a text classification problem, which can be tackled by fine-tuning a pre-trained language model (LM). However, a key challenge arises from the fact that relation extraction cannot straightforwardly be reduced to sequence or token classification. Existing approaches therefore solve the problem in an indirect way: they fine-tune an LM to learn embeddings of the head and tail entities, and then predict the relationship from these entity embeddings. Our hypothesis in this paper is that relation extraction models can be improved by capturing relationships in a more direct way. In particular, we experiment with appending a prompt with a [MASK] token, whose contextualised representation is treated as a relation embedding. While, on its own, this strategy significantly underperforms the aforementioned approach, we find that the resulting relation embeddings are highly complementary to what is captured by embeddings of the head and tail entity. By jointly considering both types of representations, we end up with a simple model that outperforms the state-of-the-art across several relation extraction benchmarks.
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id arxiv_https___arxiv_org_abs_2312_11062
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Entity or Relation Embeddings? An Analysis of Encoding Strategies for Relation Extraction
Mtumbuka, Frank
Schockaert, Steven
Computation and Language
Relation extraction is essentially a text classification problem, which can be tackled by fine-tuning a pre-trained language model (LM). However, a key challenge arises from the fact that relation extraction cannot straightforwardly be reduced to sequence or token classification. Existing approaches therefore solve the problem in an indirect way: they fine-tune an LM to learn embeddings of the head and tail entities, and then predict the relationship from these entity embeddings. Our hypothesis in this paper is that relation extraction models can be improved by capturing relationships in a more direct way. In particular, we experiment with appending a prompt with a [MASK] token, whose contextualised representation is treated as a relation embedding. While, on its own, this strategy significantly underperforms the aforementioned approach, we find that the resulting relation embeddings are highly complementary to what is captured by embeddings of the head and tail entity. By jointly considering both types of representations, we end up with a simple model that outperforms the state-of-the-art across several relation extraction benchmarks.
title Entity or Relation Embeddings? An Analysis of Encoding Strategies for Relation Extraction
topic Computation and Language
url https://arxiv.org/abs/2312.11062