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arXiv 2602.08548cs.CL
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语言模型如何理解表格?对单元格定位的机制分析

How Do Language Models Understand Tables? A Mechanistic Analysis of Cell Location

Harbin Institute of Technology(哈尔滨工业大学)

Xuanliang Zhang, Dingzirui Wang, Keyan Xu, Qingfu Zhu, Wanxiang Che

AI总结:

本研究通过分析语言模型处理表格的机制,揭示了单元格定位的三阶段流程,包括语义绑定、坐标定位和信息提取,并展示了模型如何通过离散分隔符计数和线性子空间编码实现表格理解。

摘要:

尽管大型语言模型(LLMs)越来越多地用于表格相关任务,但使它们能够处理线性化二维结构化表格的内部机制仍然不透明。在本工作中,我们通过分解原子任务“单元格定位”来研究表格理解的过程。通过激活补丁和互补可解释性技术,我们将表格理解机制分解为一个连续的三阶段流水线:语义绑定、坐标定位和信息提取。我们证明模型通过一种顺序机制来定位目标单元格,该机制通过计数离散分隔符来解析坐标。此外,列索引被编码在一个线性子空间中,这使得通过向量算术能够精确地引导模型的焦点。最后,我们揭示模型通过复用在原子定位期间识别出的相同注意力头来推广到多单元格定位任务。我们的发现为Transformer架构中的表格理解提供了全面的解释。

英文摘要:

While Large Language Models (LLMs) are increasingly deployed for table-related tasks, the internal mechanisms enabling them to process linearized two-dimensional structured tables remain opaque. In this work, we investigate the process of table understanding by dissecting the atomic task of cell location. Through activation patching and complementary interpretability techniques, we delineate the table understanding mechanism into a sequential three-stage pipeline: Semantic Binding, Coordinate Localization, and Information Extraction. We demonstrate that models locate the target cell via an ordinal mechanism that counts discrete delimiters to resolve coordinates. Furthermore, column indices are encoded within a linear subspace that allows for precise steering of model focus through vector arithmetic. Finally, we reveal that models generalize to multi-cell location tasks by multiplexing the identical attention heads identified during atomic location. Our findings provide a comprehensive explanation of table understanding within Transformer architectures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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