Hyowon Cho


2025

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CheckEval: A reliable LLM-as-a-Judge framework for evaluating text generation using checklists
Yukyung Lee | JoongHoon Kim | Jaehee Kim | Hyowon Cho | Jaewook Kang | Pilsung Kang | Najoung Kim
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Existing LLM-as-a-Judge approaches for evaluating text generation suffer from rating inconsistencies, with low agreement and high rating variance across different evaluator models. We attribute this to subjective evaluation criteria combined with Likert scale scoring in existing protocols. To address this issue, we introduce CheckEval, a checklist-based evaluation framework that improves rating reliability via decomposed binary questions. Through experiments with 12 evaluator models across multiple datasets, we first demonstrate that CheckEval strongly correlates with human judgments. More importantly, CheckEval dramatically improves the average agreement across evaluator models by 0.45 and reduces the score variance. CheckEval scores furthermore have the benefit of being more interpretable because it decomposes evaluation criteria into traceable binary decisions, allowing analyses of specific attributes driving quality judgments.

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The BiGGen Bench: A Principled Benchmark for Fine-grained Evaluation of Language Models with Language Models
Seungone Kim | Juyoung Suk | Ji Yong Cho | Shayne Longpre | Chaeeun Kim | Dongkeun Yoon | Guijin Son | Yejin Cho | Sheikh Shafayat | Jinheon Baek | Sue Hyun Park | Hyeonbin Hwang | Jinkyung Jo | Hyowon Cho | Haebin Shin | Seongyun Lee | Hanseok Oh | Noah Lee | Namgyu Ho | Se June Joo | Miyoung Ko | Yoonjoo Lee | Hyungjoo Chae | Jamin Shin | Joel Jang | Seonghyeon Ye | Bill Yuchen Lin | Sean Welleck | Graham Neubig | Moontae Lee | Kyungjae Lee | Minjoon Seo
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)

As language models (LMs) become capable of handling a wide range of tasks, their evaluation is becoming as challenging as their development. Most generation benchmarks currently assess LMs using abstract evaluation criteria-like helpfulness and harmlessness-which often lack the flexibility and granularity of human assessment. Additionally, these benchmarks tend to focus disproportionately on specific capabilities such as instruction following, leading to coverage bias. To overcome these limitations, we introduce the BiGGen Bench, a principled generation benchmark designed to thoroughly evaluate nine distinct capabilities of LMs across 77 diverse tasks. A key feature of the BiGGen Bench is its use of instance-specific evaluation criteria, closely mirroring the nuanced discernment of human evaluation. We apply this benchmark to assess 100 frontier LMs using five evaluator LMs. Our code, data, and evaluation results are all publicly available at https://github.com/prometheus-eval/prometheus-eval.

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Towards Reliable and Practical Phishing Detection
Hyowon Cho | Minjoon Seo
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 3: Industry Track)

As the prevalence of phishing attacks continues to rise, there is an increasing demand for more robust detection technologies. With recent advances in AI, we discuss how to construct a reliable and practical phishing detection system using language models. For this system, we introduce the first large-scale Korean dataset for phishing detection, encompassing six types of phishing attacks. We consider multiple factors for building a real-time detection system for edge devices, such as model size, Speech-To-Text quality, split length, training technique and multi-task learning. We evaluate the model’s ability twofold: in-domain, and unseen attack detection performance which is referred to as zero-day performance. Additionally, we demonstrate the importance of accurate comparison groups and evaluation datasets, showing that voice phishing detection performs reasonably well while smishing detection remains challenging. Both the dataset and the trained model will be available upon request.