MODABS: Multi-Objective Learning for Dynamic Aspect-Based Summarization
Xiaobo Guo, Soroush Vosoughi
TL;DR
MODABS addresses dynamic aspect-based summarization by jointly discovering and summarizing multiple aspects without predefined counts. It extends Longformer-Encoder-Decoder with a multi-objective fine-tuning regime that predicts the number of aspects, enforces distinct, high-quality per-aspect summaries, and promotes diversity across aspects via KL-divergence constraints. Empirical results on Disordered-DABS and OASUM show consistent improvements over strong baselines and LLM prompting, with notably accurate aspect-count predictions and enhanced multi-aspect quality in human judgments. This approach offers a scalable, encoder-agnostic strategy for robust, domain-agnostic dynamic AB summarization in long-form content.
Abstract
The rapid proliferation of online content necessitates effective summarization methods, among which dynamic aspect-based summarization stands out. Unlike its traditional counterpart, which assumes a fixed set of known aspects, this approach adapts to the varied aspects of the input text. We introduce a novel multi-objective learning framework employing a Longformer-Encoder-Decoder for this task. The framework optimizes aspect number prediction, minimizes disparity between generated and reference summaries for each aspect, and maximizes dissimilarity across aspect-specific summaries. Extensive experiments show our method significantly outperforms baselines on three diverse datasets, largely due to the effective alignment of generated and reference aspect counts without sacrificing single-aspect summarization quality.
