Chao-Chun Hsu
2026
CodeScout: Contextual Problem Statement Enhancement for Software Agents
Manan Suri | Xiangci Li | Mehdi Shojaie | Songyang Han | Chao-Chun Hsu | Shweta Garg | Aniket Anand Deshmukh | Varun Kumar
Findings of the Association for Computational Linguistics: ACL 2026
Manan Suri | Xiangci Li | Mehdi Shojaie | Songyang Han | Chao-Chun Hsu | Shweta Garg | Aniket Anand Deshmukh | Varun Kumar
Findings of the Association for Computational Linguistics: ACL 2026
Current AI-powered code assistance tools often struggle with ambiguous problem statements that lack sufficient task context and requirements specification. Recent analysis of software engineering agents reveals that failures on such ambiguous requests are highly correlated with longer trajectories involving either over-exploration or repeated attempts at applying the same fix without proper evolution or testing, leading to suboptimal outcomes across software development tasks. We introduce CodeScout, a breakthrough contextual query refinement approach that systematically converts ambiguous user requests into comprehensive, actionable problem statements through lightweight pre-exploration of the target codebase. Our key innovation is demonstrating that structured analysis before task execution can supplement existing agentic capabilities without requiring any modifications to their underlying scaffolds. CodeScout performs targeted context scoping, conducts multi-perspective analysis examining potential fixes and exploration opportunities, then synthesizes these insights into enhanced problem statements with reproduction steps, expected behaviors, and targeted exploration hints. This pre-exploration directly addresses the identified failure patterns by reducing non-converging agent trajectories while clarifying user intent in natural language space. We evaluate CodeScout using state-of-the-art agentic scaffolds and language models on SWEBench-Verified, demonstrating a 20% improvement in resolution rates with up to 27 additional issues resolved compared to the default baseline method. Our results suggest that systematic query refinement through contextual analysis represents a promising direction for enhancing AI code assistance capabilities.
CODESTRUCT: Code Agents over Structured Action Spaces
Myeongsoo Kim | Chao-Chun Hsu | Dingmin Wang | Shweta Garg | Varun Kumar | Murali Krishna Ramanathan
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Myeongsoo Kim | Chao-Chun Hsu | Dingmin Wang | Shweta Garg | Varun Kumar | Murali Krishna Ramanathan
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
LLM-based code agents treat repositories as unstructured text, applying edits through brittle string matching that frequently fails due to formatting drift or ambiguous patterns. We propose reframing the codebase as a structured action space where agents operate on named AST entities rather than text spans. Our framework, CodeStruct, provides readCode for retrieving complete syntactic units and editCode for applying syntax-validated transformations to semantic program elements. Evaluated on SWE-Bench Verified across six LLMs, CodeStruct improves Pass@1 accuracy by 1.2-5.0% while reducing token consumption by 12-38% for most models. Models that frequently fail to produce valid patches under text-based interfaces benefit most: GPT-5-nano improves by 20.8% as empty-patch failures drop from 46.6% to 7.2%. On CodeAssistBench, we observe consistent accuracy gains (+0.8-4.4%) with cost reductions up to 33%. Our results show that structure-aware interfaces offer a more reliable foundation for code agents.
2024
CHIME: LLM-Assisted Hierarchical Organization of Scientific Studies for Literature Review Support
Chao-Chun Hsu | Erin Bransom | Jenna Sparks | Bailey Kuehl | Chenhao Tan | David Wadden | Lucy Wang | Aakanksha Naik
Findings of the Association for Computational Linguistics: ACL 2024
Chao-Chun Hsu | Erin Bransom | Jenna Sparks | Bailey Kuehl | Chenhao Tan | David Wadden | Lucy Wang | Aakanksha Naik
Findings of the Association for Computational Linguistics: ACL 2024
Literature review requires researchers to synthesize a large amount of information and is increasingly challenging as the scientific literature expands. In this work, we investigate the potential of LLMs for producing hierarchical organizations of scientific studies to assist researchers with literature review. We define hierarchical organizations as tree structures where nodes refer to topical categories and every node is linked to the studies assigned to that category. Our naive LLM-based pipeline for hierarchy generation from a set of studies produces promising yet imperfect hierarchies, motivating us to collect CHIME, an expert-curated dataset for this task focused on biomedicine. Given the challenging and time-consuming nature of building hierarchies from scratch, we use a human-in-the-loop process in which experts correct errors (both links between categories and study assignment) in LLM-generated hierarchies. CHIME contains 2,174 LLM-generated hierarchies covering 472 topics, and expert-corrected hierarchies for a subset of 100 topics. Expert corrections allow us to quantify LLM performance, and we find that while they are quite good at generating and organizing categories, their assignment of studies to categories could be improved. We attempt to train a corrector model with human feedback which improves study assignment by 12.6 F1 points. We release our dataset and models to encourage research on developing better assistive tools for literature review.
2021
Answer Generation for Retrieval-based Question Answering Systems
Chao-Chun Hsu | Eric Lind | Luca Soldaini | Alessandro Moschitti
Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021
Chao-Chun Hsu | Eric Lind | Luca Soldaini | Alessandro Moschitti
Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021
Decision-Focused Summarization
Chao-Chun Hsu | Chenhao Tan
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Chao-Chun Hsu | Chenhao Tan
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Relevance in summarization is typically de- fined based on textual information alone, without incorporating insights about a particular decision. As a result, to support risk analysis of pancreatic cancer, summaries of medical notes may include irrelevant information such as a knee injury. We propose a novel problem, decision-focused summarization, where the goal is to summarize relevant information for a decision. We leverage a predictive model that makes the decision based on the full text to provide valuable insights on how a decision can be inferred from text. To build a summary, we then select representative sentences that lead to similar model decisions as using the full text while accounting for textual non-redundancy. To evaluate our method (DecSum), we build a testbed where the task is to summarize the first ten reviews of a restaurant in support of predicting its future rating on Yelp. DecSum substantially outperforms text-only summarization methods and model-based explanation methods in decision faithfulness and representativeness. We further demonstrate that DecSum is the only method that enables humans to outperform random chance in predicting which restaurant will be better rated in the future.
2020
Characterizing the Value of Information in Medical Notes
Chao-Chun Hsu | Shantanu Karnwal | Sendhil Mullainathan | Ziad Obermeyer | Chenhao Tan
Findings of the Association for Computational Linguistics: EMNLP 2020
Chao-Chun Hsu | Shantanu Karnwal | Sendhil Mullainathan | Ziad Obermeyer | Chenhao Tan
Findings of the Association for Computational Linguistics: EMNLP 2020
Machine learning models depend on the quality of input data. As electronic health records are widely adopted, the amount of data in health care is growing, along with complaints about the quality of medical notes. We use two prediction tasks, readmission prediction and in-hospital mortality prediction, to characterize the value of information in medical notes. We show that as a whole, medical notes only provide additional predictive power over structured information in readmission prediction. We further propose a probing framework to select parts of notes that enable more accurate predictions than using all notes, despite that the selected information leads to a distribution shift from the training data (“all notes”). Finally, we demonstrate that models trained on the selected valuable information achieve even better predictive performance, with only 6.8%of all the tokens for readmission prediction.
2018
SocialNLP 2018 EmotionX Challenge Overview: Recognizing Emotions in Dialogues
Chao-Chun Hsu | Lun-Wei Ku
Proceedings of the Sixth International Workshop on Natural Language Processing for Social Media
Chao-Chun Hsu | Lun-Wei Ku
Proceedings of the Sixth International Workshop on Natural Language Processing for Social Media
This paper describes an overview of the Dialogue Emotion Recognition Challenge, EmotionX, at the Sixth SocialNLP Workshop, which recognizes the emotion of each utterance in dialogues. This challenge offers the EmotionLines dataset as the experimental materials. The EmotionLines dataset contains conversations from Friends TV show transcripts (Friends) and real chatting logs (EmotionPush), where every dialogue utterance is labeled with emotions. Organizers provide baseline results. 18 teams registered in this challenge and 5 of them submitted their results successfully. The best team achieves the unweighted accuracy 62.48 and 62.5 on EmotionPush and Friends, respectively. In this paper we present the task definition, test collection, the evaluation results of the groups that participated in this challenge, and their approach.
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Co-authors
- Chenhao Tan 3
- Shweta Garg 2
- Lun-Wei Ku 2
- Varun Kumar 2
- Erin Bransom 1
- Sheng-Yeh Chen 1
- Aniket Anand Deshmukh 1
- Songyang Han 1
- Ting-Hao Huang 1
- Shantanu Karnwal 1
- Myeongsoo Kim 1
- Bailey Kuehl 1
- Chuan-Chun Kuo 1
- Xiangci Li 1
- Eric Lind 1
- Alessandro Moschitti 1
- Sendhil Mullainathan 1
- Aakanksha Naik 1
- Ziad Obermeyer 1
- Murali Krishna Ramanathan 1
- Mehdi Shojaie 1
- Luca Soldaini 1
- Jenna Sparks 1
- Manan Suri 1
- David Wadden 1
- Dingmin Wang 1
- Lucy Lu Wang 1