Abstract Meaning Representation (AMR) is a Semantic Parsing formalism that aims at providing a semantic graph abstraction representing a given text. Current approaches are based on autoregressive language models such as BART or T5, fine-tuned through Teacher Forcing to obtain a linearized version of the AMR graph from a sentence. In this paper, we present LeakDistill, a model and method that explores a modification to the Transformer architecture, using structural adapters to explicitly incorporate graph information into the learned representations and improve AMR parsing performance. Our experiments show how, by employing word-to-node alignment to embed graph structural information into the encoder at training time, we can obtain state-of-the-art AMR parsing through self-knowledge distillation, even without the use of additional data. We release the code at \url{http://www.github.com/sapienzanlp/LeakDistill}.
翻译:摘要:抽象语义表示(AMR)是一种语义解析形式体系,旨在提供表示给定文本的语义图抽象。当前方法基于自回归语言模型(如BART或T5),通过教师强制(Teacher Forcing)微调,从句子中获取AMR图的线性化版本。本文提出LeakDistill模型与方法,探索对Transformer架构的改进,利用结构适配器将图信息显式融入学习表示中,从而提升AMR解析性能。实验表明,通过在训练时利用词-节点对齐将图结构信息嵌入编码器,即使不使用额外数据,也能通过自知识蒸馏获得最先进的AMR解析结果。相关代码已在 \url{http://www.github.com/sapienzanlp/LeakDistill} 开源。