Token-Level Fact Correction in Abstractive Summarization

This paper addresses fact correction for abstractive summarization of which aim is to edit a system-generated summary into a new source-consistent summary. The summaries generated by abstractive summarization models often contain various kinds of factual errors. Thus, fact correction becomes essenti...

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Main Authors: Jeongwan Shin, Seong-Bae Park, Hyun-Je Song
Format: Article
Language:English
Published: IEEE 2023-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10005108/
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author Jeongwan Shin
Seong-Bae Park
Hyun-Je Song
author_facet Jeongwan Shin
Seong-Bae Park
Hyun-Je Song
author_sort Jeongwan Shin
collection DOAJ
description This paper addresses fact correction for abstractive summarization of which aim is to edit a system-generated summary into a new source-consistent summary. The summaries generated by abstractive summarization models often contain various kinds of factual errors. Thus, fact correction becomes essential to apply abstractive summarization to real-world applications. However, most existing methods for fact correction focus only on entity-level errors, which occasions the error correction methods to miss non-entity errors such as inconsistent tokens or mentions. Therefore, this paper presents a token-level fact correction that resolves inconsistencies of a system-generated summary at the token level. Since a token is the smallest meaning-bearing unit, all kinds of errors can be corrected if the errors are rectified at this level. The proposed fact corrector examines the consistency of a summary at the summary level like existing methods, but corrects the found inconsistencies at the token level. Thus, the proposed corrector consists of three modules of a summary fact checker, a token fact checker, and a fact emender. The summary fact checker inspects if a system-generated summary is factually consistent with a source text, the token fact checker finds out the tokens which cause inconsistency, and the fact emender actually replaces the inconsistency-causing tokens with correct tokens in the source text. Since these modules are closely related and affect one another, they are jointly trained to improve the performance of each module. The effectiveness of the proposed fact corrector is empirically proven from two viewpoints of consistency and summarization performance. For correcting inconsistencies in a summary, it is shown that the summaries by the proposed corrector are more factually consistent than those by its competitors. In addition, the proposed corrector outperforms the current state-of-the-art corrector even in automatic summarization performance.
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spelling doaj.art-d11dad918aee4de79fbd4649012c05472023-01-11T00:00:40ZengIEEEIEEE Access2169-35362023-01-01111934194310.1109/ACCESS.2022.323385410005108Token-Level Fact Correction in Abstractive SummarizationJeongwan Shin0https://orcid.org/0000-0002-6990-2892Seong-Bae Park1https://orcid.org/0000-0002-6453-0348Hyun-Je Song2https://orcid.org/0000-0002-9109-2611School of Computer Science and Engineering, Kyungpook National University, Daegu, South KoreaSchool of Computer Science and Engineering, Kyung Hee University, Yongin-si, South KoreaDepartment of Information Technology and Engineering, Jeonbuk National University, Jeonju-si, South KoreaThis paper addresses fact correction for abstractive summarization of which aim is to edit a system-generated summary into a new source-consistent summary. The summaries generated by abstractive summarization models often contain various kinds of factual errors. Thus, fact correction becomes essential to apply abstractive summarization to real-world applications. However, most existing methods for fact correction focus only on entity-level errors, which occasions the error correction methods to miss non-entity errors such as inconsistent tokens or mentions. Therefore, this paper presents a token-level fact correction that resolves inconsistencies of a system-generated summary at the token level. Since a token is the smallest meaning-bearing unit, all kinds of errors can be corrected if the errors are rectified at this level. The proposed fact corrector examines the consistency of a summary at the summary level like existing methods, but corrects the found inconsistencies at the token level. Thus, the proposed corrector consists of three modules of a summary fact checker, a token fact checker, and a fact emender. The summary fact checker inspects if a system-generated summary is factually consistent with a source text, the token fact checker finds out the tokens which cause inconsistency, and the fact emender actually replaces the inconsistency-causing tokens with correct tokens in the source text. Since these modules are closely related and affect one another, they are jointly trained to improve the performance of each module. The effectiveness of the proposed fact corrector is empirically proven from two viewpoints of consistency and summarization performance. For correcting inconsistencies in a summary, it is shown that the summaries by the proposed corrector are more factually consistent than those by its competitors. In addition, the proposed corrector outperforms the current state-of-the-art corrector even in automatic summarization performance.https://ieeexplore.ieee.org/document/10005108/Token-level fact correctionfactual consistency in abstractive summarizationsummary fact checkertoken fact checkerfact emender
spellingShingle Jeongwan Shin
Seong-Bae Park
Hyun-Je Song
Token-Level Fact Correction in Abstractive Summarization
IEEE Access
Token-level fact correction
factual consistency in abstractive summarization
summary fact checker
token fact checker
fact emender
title Token-Level Fact Correction in Abstractive Summarization
title_full Token-Level Fact Correction in Abstractive Summarization
title_fullStr Token-Level Fact Correction in Abstractive Summarization
title_full_unstemmed Token-Level Fact Correction in Abstractive Summarization
title_short Token-Level Fact Correction in Abstractive Summarization
title_sort token level fact correction in abstractive summarization
topic Token-level fact correction
factual consistency in abstractive summarization
summary fact checker
token fact checker
fact emender
url https://ieeexplore.ieee.org/document/10005108/
work_keys_str_mv AT jeongwanshin tokenlevelfactcorrectioninabstractivesummarization
AT seongbaepark tokenlevelfactcorrectioninabstractivesummarization
AT hyunjesong tokenlevelfactcorrectioninabstractivesummarization