SCaLAR_NITK @ JUSTNLP Legal Summarization (L-SUMM) Shared Task

AbstractThis paper presents the systems we submitted to the JUST-NLP 2025 Shared Task on Legal Summarization (L-SUMM). Creating abstractive summaries of lengthy Indian court rulings is challenging due to transformer token limits. To address this problem, we compare three systems built on a fine-tuned Legal Pegasus model. System 1 (Baseline) applies a standard hierarchical framework that chunks long documents using naive token-based segmentation. System 2 (RR-Chunk) improves this approach by using a BERT-BiLSTM model to tag sentences with rhetorical roles (RR) and incorporating these tags (e.g., [Facts]. . . ) to enable structurally informed chunking for hierarchical summarization. System 3 (WRR-Tune) tests whether explicit importance cues help the model by assigning importance scores to each RR using the geometric mean of their distributional presence in judgments and human summaries, and finetuning a separate model on text augmented with these tags (e.g., [Facts, importance score 13.58]). A comparison of the three systems demonstrates the value of progressively adding structural and quantitative importance signals to the model’s input.