Kosuke Takahashi
2026
Aggregate vs. Personalized Judges in Business Idea Evaluation: Evidence from Expert Disagreement
Wataru Hirota | Tomoki Taniguchi | Tomoko Ohkuma | Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Takuto Asakura | Chung-Chi Chen | Tatsuya Ishigaki
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Wataru Hirota | Tomoki Taniguchi | Tomoko Ohkuma | Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Takuto Asakura | Chung-Chi Chen | Tatsuya Ishigaki
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Evaluating LLM-generated business ideas is often harder to scale than generating them.Unlike standard NLP benchmarks, business idea evaluation relies on multi-dimensional criteria such as feasibility, novelty, differentiation, user need, and market size, and expert judgments often disagree.This paper studies a methodological question raised by such disagreement: should an automatic judge approximate an aggregate consensus, or model evaluators individually?We introduce PBIG-DATA, a dataset of approximately 3,000 individual scores across 300 patent-grounded product ideas, provided by domain experts on six business-oriented dimensions:specificity, technical validity, innovativeness, competitive advantage, need validity, and market size.Analyses show substantial expert disagreement on fine-grained ordinal scores, while agreement is higher under coarse selection, suggesting structured heterogeneity rather than random noise.We then compare three judge configurations: a rubric-only zero-shot judge, an aggregate judge conditioned on mixed evaluator histories, and a personalized judge conditioned on the target evaluator’s scoring history.Across dimensions and model sizes, personalized judges align more closely with the corresponding evaluator than aggregate judges, and evaluator agreement correlates with similarity of judge-generated reasoning only under personalized conditioning.These results indicate that pooled labels can be a fragile target in pluralistic evaluation settings and motivate evaluator-conditioned judge designs for business idea assessment.
2025
Exploring the Design of Multi-Agent LLM Dialogues for Research Ideation
Keisuke Ueda | Wataru Hirota | Takuto Asakura | Takahiro Omi | Kosuke Takahashi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 26th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Keisuke Ueda | Wataru Hirota | Takuto Asakura | Takahiro Omi | Kosuke Takahashi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 26th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Large language models (LLMs) are increasingly used to support creative tasks such as research idea generation. While recent work has shown that structured dialogues between LLMs can improve the novelty and feasibility of generated ideas, the optimal design of such interactions remains unclear. In this study, we conduct a comprehensive analysis of multi-agent LLM dialogues for scientific ideation. We compare different configurations of agent roles, number of agents, and dialogue depth to understand how these factors influence the novelty and feasibility of generated ideas. Our experimental setup includes settings where one agent generates ideas and another critiques them, enabling iterative improvement. Our results show that enlarging the agent cohort, deepening the interaction depth, and broadening agent persona heterogeneity each enrich the diversity of generated ideas. Moreover, specifically increasing critic-side diversity within the ideation–critique–revision loop further boosts the feasibility of the final proposals. Our findings offer practical guidelines for building effective multi-agent LLM systems for scientific ideation.
2024
Pretraining and Updates of Domain-Specific LLM: A Case Study in the Japanese Business Domain
Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 38th Pacific Asia Conference on Language, Information and Computation
Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 38th Pacific Asia Conference on Language, Information and Computation
2023
Training Generative Question-Answering on Synthetic Data Obtained from an Instruct-tuned Model
Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 37th Pacific Asia Conference on Language, Information and Computation
Kosuke Takahashi | Takahiro Omi | Kosuke Arima | Tatsuya Ishigaki
Proceedings of the 37th Pacific Asia Conference on Language, Information and Computation
2021
Multilingual Machine Translation Evaluation Metrics Fine-tuned on Pseudo-Negative Examples for WMT 2021 Metrics Task
Kosuke Takahashi | Yoichi Ishibashi | Katsuhito Sudoh | Satoshi Nakamura
Proceedings of the Sixth Conference on Machine Translation
Kosuke Takahashi | Yoichi Ishibashi | Katsuhito Sudoh | Satoshi Nakamura
Proceedings of the Sixth Conference on Machine Translation
This paper describes our submission to the WMT2021 shared metrics task. Our metric is operative to segment-level and system-level translations. Our belief toward a better metric is to detect a significant error that cannot be missed in the real practice cases of evaluation. For that reason, we used pseudo-negative examples in which attributes of some words are transferred to the reversed attribute words, and we build evaluation models to handle such serious mistakes of translations. We fine-tune a multilingual largely pre-trained model on the provided corpus of past years’ metric task and fine-tune again further on the synthetic negative examples that are derived from the same fine-tune corpus. From the evaluation results of the WMT21’s development corpus, fine-tuning on the pseudo-negatives using WMT15-17 and WMT18-20 metric corpus achieved a better Pearson’s correlation score than the one fine-tuned without negative examples. Our submitted models,hyp+src_hyp+ref and hyp+src_hyp+ref.negative, are the plain model using WMT18-20 and the one additionally fine-tuned on negative samples, respectively.
Is This Translation Error Critical?: Classification-Based Human and Automatic Machine Translation Evaluation Focusing on Critical Errors
Katsuhito Sudoh | Kosuke Takahashi | Satoshi Nakamura
Proceedings of the Workshop on Human Evaluation of NLP Systems (HumEval)
Katsuhito Sudoh | Kosuke Takahashi | Satoshi Nakamura
Proceedings of the Workshop on Human Evaluation of NLP Systems (HumEval)
This paper discusses a classification-based approach to machine translation evaluation, as opposed to a common regression-based approach in the WMT Metrics task. Recent machine translation usually works well but sometimes makes critical errors due to just a few wrong word choices. Our classification-based approach focuses on such errors using several error type labels, for practical machine translation evaluation in an age of neural machine translation. We made additional annotations on the WMT 2015-2017 Metrics datasets with fluency and adequacy labels to distinguish different types of translation errors from syntactic and semantic viewpoints. We present our human evaluation criteria for the corpus development and automatic evaluation experiments using the corpus. The human evaluation corpus will be publicly available upon publication.
2020
Automatic Machine Translation Evaluation using Source Language Inputs and Cross-lingual Language Model
Kosuke Takahashi | Katsuhito Sudoh | Satoshi Nakamura
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
Kosuke Takahashi | Katsuhito Sudoh | Satoshi Nakamura
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
We propose an automatic evaluation method of machine translation that uses source language sentences regarded as additional pseudo references. The proposed method evaluates a translation hypothesis in a regression model. The model takes the paired source, reference, and hypothesis sentence all together as an input. A pretrained large scale cross-lingual language model encodes the input to sentence-pair vectors, and the model predicts a human evaluation score with those vectors. Our experiments show that our proposed method using Cross-lingual Language Model (XLM) trained with a translation language modeling (TLM) objective achieves a higher correlation with human judgments than a baseline method that uses only hypothesis and reference sentences. Additionally, using source sentences in our proposed method is confirmed to improve the evaluation performance.