Rahul Mehta


2024

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Halu-NLP at SemEval-2024 Task 6: MetaCheckGPT - A Multi-task Hallucination Detection using LLM uncertainty and meta-models
Rahul Mehta | Andrew Hoblitzell | Jack O’keefe | Hyeju Jang | Vasudeva Varma
Proceedings of the 18th International Workshop on Semantic Evaluation (SemEval-2024)

Hallucinations in large language models(LLMs) have recently become a significantproblem. A recent effort in this directionis a shared task at Semeval 2024 Task 6,SHROOM, a Shared-task on Hallucinationsand Related Observable Overgeneration Mis-takes. This paper describes our winning so-lution ranked 1st and 2nd in the 2 sub-tasksof model agnostic and model aware tracks re-spectively. We propose a meta-regressor basedensemble of LLMs based on a random forestalgorithm that achieves the highest scores onthe leader board. We also experiment with var-ious transformer based models and black boxmethods like ChatGPT, Vectara, and others. Inaddition, we perform an error analysis com-paring ChatGPT against our best model whichshows the limitations of the former

2023

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LLM-RM at SemEval-2023 Task 2: Multilingual Complex NER Using XLM-RoBERTa
Rahul Mehta | Vasudeva Varma
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

Named Entity Recognition(NER) is a task ofrecognizing entities at a token level in a sen-tence. This paper focuses on solving NER tasksin a multilingual setting for complex named en-tities. Our team, LLM-RM participated in therecently organized SemEval 2023 task, Task 2:MultiCoNER II,Multilingual Complex NamedEntity Recognition. We approach the problemby leveraging cross-lingual representation pro-vided by fine-tuning XLM-Roberta base modelon datasets of all of the 12 languages provided - Bangla, Chinese, English, Farsi, French,German, Hindi, Italian, Portuguese, Spanish,Swedish and Ukrainian.

2004

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Learning to Resolve Bridging References
Massimo Poesio | Rahul Mehta | Axel Maroudas | Janet Hitzeman
Proceedings of the 42nd Annual Meeting of the Association for Computational Linguistics (ACL-04)