Heterogeneous Information-Driven Contrastive Optimization for Abstractive Summarization
摘要
Abstractive summarization task aims to generate a concise and accurate summary that effectively captures the key information from the input document. In recent years, large language models (LLMs) have emerged as foundational models for developing domain-specific summarization systems. While these models are effective, they also tend to inherit the hallucinations produced by LLMs. Furthermore, the fundamental inconsistency between training objectives and inference protocols in summarization systems have yet to be effectively resolved. Addressing both two issues, we introduce Heterogeneous Information-Driven Contrastive optimization for abstractive summarization (HICON). The proposed method integrates the classic Tensor-Product Representation into abstractive summarization, enabling the capture of syntactic information from the source document. By integrating syntactic information with semantic features, the summarization model gains a fine-grained understanding of the document, thus generating more faithful summaries. Considering the inconsistency problem, HICON selects the generated summaries as training examples and incorporates contrastive learning loss alongside generative loss to bridge the gap between training and inference. Experimental results shows that our method achieves new state-of-the-art results on the CNN/Daily Mail dataset, with a R-1 score of 49.22. Further analysis reveals that the summaries produced by HICON exhibit greater relevance to the source document, enhanced fluency, and fewer errors.