@inproceedings{aryal-akomoize-2025-howard,
title = "{H}oward {U}niversity - {AI}4{PC} at {S}em{E}val-2025 Task 3: Logit-based Supervised Token Classification for Multilingual Hallucination Span Identification Using {XGBOD}",
author = "Aryal, Saurav and
Akomoize, Mildness",
editor = "Rosenthal, Sara and
Ros{\'a}, Aiala and
Ghosh, Debanjan and
Zampieri, Marcos",
booktitle = "Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)",
month = jul,
year = "2025",
address = "Vienna, Austria",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2025.semeval-1.236/",
pages = "1790--1794",
ISBN = "979-8-89176-273-2",
abstract = "This paper describes our system for SemEval-2025 Task 3, Mu-SHROOM, which focuses on detecting hallucination spans in multilingual LLM outputs. We reframe hallucination detection as a point-wise anomaly detection problem by treating logits as time-series data. Our approach extracts features from token-level logits, addresses class imbalance with SMOTE, and trains an XGBOD model for probabilistic character-level predictions. Our system, which relies solely on information derived from the logits and token offsets (using pretrained tokenizers), achieves competitive intersection-over-union (IoU) and correlation scores on the validation and test set."
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<abstract>This paper describes our system for SemEval-2025 Task 3, Mu-SHROOM, which focuses on detecting hallucination spans in multilingual LLM outputs. We reframe hallucination detection as a point-wise anomaly detection problem by treating logits as time-series data. Our approach extracts features from token-level logits, addresses class imbalance with SMOTE, and trains an XGBOD model for probabilistic character-level predictions. Our system, which relies solely on information derived from the logits and token offsets (using pretrained tokenizers), achieves competitive intersection-over-union (IoU) and correlation scores on the validation and test set.</abstract>
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%0 Conference Proceedings
%T Howard University - AI4PC at SemEval-2025 Task 3: Logit-based Supervised Token Classification for Multilingual Hallucination Span Identification Using XGBOD
%A Aryal, Saurav
%A Akomoize, Mildness
%Y Rosenthal, Sara
%Y Rosá, Aiala
%Y Ghosh, Debanjan
%Y Zampieri, Marcos
%S Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)
%D 2025
%8 July
%I Association for Computational Linguistics
%C Vienna, Austria
%@ 979-8-89176-273-2
%F aryal-akomoize-2025-howard
%X This paper describes our system for SemEval-2025 Task 3, Mu-SHROOM, which focuses on detecting hallucination spans in multilingual LLM outputs. We reframe hallucination detection as a point-wise anomaly detection problem by treating logits as time-series data. Our approach extracts features from token-level logits, addresses class imbalance with SMOTE, and trains an XGBOD model for probabilistic character-level predictions. Our system, which relies solely on information derived from the logits and token offsets (using pretrained tokenizers), achieves competitive intersection-over-union (IoU) and correlation scores on the validation and test set.
%U https://aclanthology.org/2025.semeval-1.236/
%P 1790-1794
Markdown (Informal)
[Howard University - AI4PC at SemEval-2025 Task 3: Logit-based Supervised Token Classification for Multilingual Hallucination Span Identification Using XGBOD](https://aclanthology.org/2025.semeval-1.236/) (Aryal & Akomoize, SemEval 2025)
ACL