Andy T. Liu

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2025

Clinical abstractive summarization struggles to balance faithfulness and informativeness, sacrificing key information or introducing confabulations. Techniques like in-context learning and fine-tuning have improved overall summary quality orthogonally, without considering the above issue. Conversely, methods aimed at improving faithfulness and informativeness, such as model reasoning and self improvement, have not been systematically evaluated in the clinical domain. We address this gap by first performing a comprehensive benchmark and study of six advanced abstractive summarization methods across three datasets using five reference-based and reference-free metrics, with the latter specifically assessing faithfulness and informativeness. Based on its findings we then develop uMedSum, a modular hybrid framework introducing novel approaches for sequential confabulation removal and key information addition. Our work outperforms previous GPT-4-based state-of-the-art (SOTA) methods in both quantitative metrics and expert evaluations, achieving an 11.8% average improvement in dedicated faithfulness metrics over the previous SOTA. Doctors prefer uMedSum’s summaries 6 times more than previous SOTA in difficult cases containing confabulations or missing information. These results highlight uMedSum’s effectiveness and generalizability across various datasets and metrics, marking a significant advancement in clinical summarization. uMedSum toolkit is made available on GitHub.

2022

Transfer learning has proven to be crucial in advancing the state of speech and natural language processing research in recent years. In speech, a model pre-trained by self-supervised learning transfers remarkably well on multiple tasks. However, the lack of a consistent evaluation methodology is limiting towards a holistic understanding of the efficacy of such models. SUPERB was a step towards introducing a common benchmark to evaluate pre-trained models across various speech tasks. In this paper, we introduce SUPERB-SG, a new benchmark focusing on evaluating the semantic and generative capabilities of pre-trained models by increasing task diversity and difficulty over SUPERB. We use a lightweight methodology to test the robustness of representations learned by pre-trained models under shifts in data domain and quality across different types of tasks. It entails freezing pre-trained model parameters, only using simple task-specific trainable heads. The goal is to be inclusive of all researchers, and encourage efficient use of computational resources. We also show that the task diversity of SUPERB-SG coupled with limited task supervision is an effective recipe for evaluating the generalizability of model representation.