论文标题
不要解雇语言学家:语法概况帮助语言模型检测语义变化
Do Not Fire the Linguist: Grammatical Profiles Help Language Models Detect Semantic Change
论文作者
论文摘要
单词用法中的形态和句法变化(例如,通过语法概况捕获)已被证明是单词含义变化的良好预测指标。在这项工作中,我们探讨了大型预训练的上下文化语言模型(词汇语义变化检测的常见工具)是否对这种形态句法变化敏感。为此,我们首先将语法概况的性能与10个数据集上的多语言神经语言模型(XLM-R)的性能进行比较,涵盖了7种语言,然后将两种方法结合在一起,以评估其互补性。我们的结果表明,使用XLM-R结合语法概况可改善大多数数据集和语言的语义变化检测性能。这表明语言模型不能完全涵盖语法概况中明确表示的细粒形态和句法信号。 一个有趣的例外是测试集,其中分析的时间比它们之间的时间差距要长得多(例如,长达一个世纪的跨度,它们之间的差距为一年)。形态句法变化很慢,因此语法曲线在这种情况下无法检测到。相比之下,语言模型,由于其访问词汇信息,能够检测到快速的主题更改。
Morphological and syntactic changes in word usage (as captured, e.g., by grammatical profiles) have been shown to be good predictors of a word's meaning change. In this work, we explore whether large pre-trained contextualised language models, a common tool for lexical semantic change detection, are sensitive to such morphosyntactic changes. To this end, we first compare the performance of grammatical profiles against that of a multilingual neural language model (XLM-R) on 10 datasets, covering 7 languages, and then combine the two approaches in ensembles to assess their complementarity. Our results show that ensembling grammatical profiles with XLM-R improves semantic change detection performance for most datasets and languages. This indicates that language models do not fully cover the fine-grained morphological and syntactic signals that are explicitly represented in grammatical profiles. An interesting exception are the test sets where the time spans under analysis are much longer than the time gap between them (for example, century-long spans with a one-year gap between them). Morphosyntactic change is slow so grammatical profiles do not detect in such cases. In contrast, language models, thanks to their access to lexical information, are able to detect fast topical changes.