BetaEdit: Null-Space Constrained Sequential Model Editing

Fuente: arXiv
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Main Authors: Liu, Bingqing, Liu, Wei, Li, Yuhua
Format: Preprint
Published: 2026
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author Liu, Bingqing
Liu, Wei
Li, Yuhua
author_facet Liu, Bingqing
Liu, Wei
Li, Yuhua
contents Null-space-based methods have garnered considerable attention in model editing by constraining updates to the null space of the pre-existing knowledge representation, thereby preserving the model's original behavior. However, in practice these methods rely on an approximate null space--leading to knowledge leakage--and further suffer from severe performance degradation during sequential editing. Recent work shows that history-aware editing strategies can empirically mitigate this decline, yet the underlying reason remains unclear. In this paper, we first expose the knowledge leakage inherent in existing null-space approaches and then analyze why history-aware updates effectively preserve both editing performance and general capabilities during long-horizon editing. Building on these insights, we propose BetaEdit, a refined framework that effectively controls the knowledge leakage and integrates history-aware updates into the null-space paradigm. Extensive experiments on three large language models across two standard benchmarks show that BetaEdit consistently outperforms prior methods in the challenging regime of massive-scale sequential editing. Code is available at: https://github.com/lbq8942/BetaEdit.
format Preprint
id arxiv_https___arxiv_org_abs_2605_09285
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle BetaEdit: Null-Space Constrained Sequential Model Editing
Liu, Bingqing
Liu, Wei
Li, Yuhua
Computation and Language
Null-space-based methods have garnered considerable attention in model editing by constraining updates to the null space of the pre-existing knowledge representation, thereby preserving the model's original behavior. However, in practice these methods rely on an approximate null space--leading to knowledge leakage--and further suffer from severe performance degradation during sequential editing. Recent work shows that history-aware editing strategies can empirically mitigate this decline, yet the underlying reason remains unclear. In this paper, we first expose the knowledge leakage inherent in existing null-space approaches and then analyze why history-aware updates effectively preserve both editing performance and general capabilities during long-horizon editing. Building on these insights, we propose BetaEdit, a refined framework that effectively controls the knowledge leakage and integrates history-aware updates into the null-space paradigm. Extensive experiments on three large language models across two standard benchmarks show that BetaEdit consistently outperforms prior methods in the challenging regime of massive-scale sequential editing. Code is available at: https://github.com/lbq8942/BetaEdit.
title BetaEdit: Null-Space Constrained Sequential Model Editing
topic Computation and Language
url https://arxiv.org/abs/2605.09285