Mexico

This work describes the system submitted by the SINAI team to the subtask A of Task 8 of SemEval 2024, as well as two additional systems evaluated during the training phase of the shared task. We claim that the perplexity score of a text may be used as a classification signal. Accordingly, we conduct a study on the utility of perplexity for discerning text authorship, and we perform a comparative analysis of the results obtained on the datasets of the task. The results of this study motivated us to use as classification features the word embeddings vectors of the input texts and its corresponding perplexity score. Likewise, the submitted system is a fine-tuning version of the XLM-RoBERTa-Large model. The analysis of the results of the evaluation shows large differences among the language probability distribution of the training and test sets. Nonetheless, the results show that perplexity can be used as feature for identifying machine generated text, hence our claim holds.

NAACL 2024

SINAI at SemEval-2024 Task 8: Fine-tuning on Words and Perplexity as Features for Detecting Machine Written Text

perplexity

gpt2

multimodal

## Welcome!
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EMNLP 2025

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workshop paper

## Welcome to 2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics!
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The University of Texas at Austin 
NAACL-2024 General Chair 
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2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics

We transfer the intuitions of humans checking possibly non-supported statements of Large Language Models (LLMs) to identify hallucinations. We ask multiple model judges with a tailored prompt to assess the hallucination probability and combine their responses. We test various models and find that bigger is not always better.

Pollice Verso at SemEval-2024 Task 6: The Roman Empire Strikes Back

This paper presents our approach and findings for SemEval-2024 Task 5, focusing on legal argument reasoning. We explored the effectiveness of fine-tuning pre-trained BERT models and the innovative application of large language models (LLMs) through prompt engineering in the context of legal texts. Our methodology in- volved a combination of techniques to address the challenges posed by legal language processing, including handling long texts and optimizing natural language understanding (NLU) capabilities for the legal domain. Our contributions were validated by achieving a third-place ranking on the SemEval 2024 Task 5 Leader- board. The results underscore the potential of LLMs and prompt engineering in enhancing legal reasoning tasks, offering insights into the evolving landscape of NLU technologies within the legal field.

SU-FMI at SemEval-2024 Task 5: From BERT Fine-Tuning to LLM Prompt Engineering - Approaches in Legal Argument Reasoning

We created the AIpom, a system designed to detect a boundary between human written and machine-generated text (SemEval2024 Task 8, Subtask C: Human-Machine Mixed Text Detection). We propose a two stage pipeline combining predictions from an instruction-tuned decoder-only model and encoder-only sequence taggers. AIpom is ranked second on the leaderboard while achieving a Mean Absolute Error of 15.94. Ablation studies confirm the benefits of pipelining encoder and decoder models, particularly in terms of improved performance.

AIpom at SemEval-2024 Task 8: Detecting AI-produced Outputs in M4

The generation of headlines, a crucial aspect of abstractive summarization, aims to compress an entire article into a concise, single line of text despite the effectiveness of modern encoderdecoder models for text generation and summarization tasks. The encoder-decoder model commonly faces challenges in accurately generating numerical content within headlines. This study empirically explored LLMs for numeralaware headline generation and proposed fewshot prompting with LLMs for numeral-aware headline generations. Experiments conducted on the NumHG dataset and NumEval-2024 test set suggest that fine-tuning LLMs on NumHG dataset enhances the performance of LLMs for numeral aware headline generation. Furthermore, few-shot prompting with LLMs surpassed the performance of fine-tuned LLMs for numeral-aware headline generation.

ClusterCore at SemEval-2024 Task 7: Few Shot Prompting With Large Language Models for Numeral-Aware Headline Generation

We describe our systems for SemEval-2024 Task 1: Semantic Textual Relatedness. We investigate the correlation between semantic relatedness and semantic similarity. Specifi- cally, we test two hypotheses: (1) similarity is a special case of relatedness, and (2) semantic relatedness is preserved under translation. We experiment with a variety of approaches which are based on explicit semantics, downstream applications, contextual embeddings, large lan- guage models (LLMs), as well as ensembles of methods. We find empirical support for our the- oretical insights. In addition, our best ensemble system yields highly competitive results in a number of diverse categories.

UAlberta at SemEval-2024 Task 1: A Potpourri of Methods for Quantifying Multilingual Semantic Textual Relatedness and Similarity

In this presentation, we describe the methods used for Quantitative Natural Language Inference(QNLI), and Quantitative Question Answering(QQA) in task1 of Semeval2024 NumEval. The challenge’s focus is to enhance the model’s quantitative understanding consequently improving its performance on certain tasks. We accomplish this task from two perspectives: (1) By integrating real-world numerical comparison data during the supervised fine-tuning(SFT) phase, we enhanced the model’s numerical sensitivity. (2) We develop an innovative reward model scoring mechanism, leveraging reinforcement learning from human feedback (RLHF) techniques to improve the model’s reasoning completeness. The experimental results demonstrate that our methods achieve outstanding performance.

Bit_numeval at SemEval-2024 Task 7: Enhance Numerical Sensitivity and Reasoning Completeness for Quantitative Understanding

The study identifies 22 persuasive techniques in multilingual memes using fine-tuning and classification strategies. we used the XLM-RoBERTA-large-twitter language model and CLIP visual model to consider image and text features simultaneously, achieving competitive rankings in English, Bulgarian, North Macedonian, and Arabic languages simultaneously consider image and text features, achieving competitive rankings in English, Bulgarian, North Macedonian, and Arabic. Notably, they achieved 2nd place ranking for Arabic language in Subtask 1.

NLPNCHU at SemEval-2024 Task 4: A Comparison of MDHC Strategy and In-domain Pre-training for Multilingual Detection of Persuasion Techniques in Memes

We present SemEval-2024 Task 10, a shared task centered on identifying emotions and finding the rationale behind their flips within monolingual English and Hindi-English code-mixed dialogues. This task comprises three distinct subtasks – emotion recognition in conversation for code-mixed dialogues, emotion flip reasoning for code-mixed dialogues, and emotion flip reasoning for English dialogues. Participating systems were tasked to automatically execute one or more of these subtasks. The datasets for these tasks comprise manually annotated conversations focusing on emotions and triggers for emotion shifts. A total of 84 partici- pants engaged in this task, with the most adept systems attaining F1-scores of 0.70, 0.79, and 0.76 for the respective subtasks. This presentation summarises the results and findings from 24 teams alongside their system descriptions.

SemEval 2024 - Task 10: Emotion Discovery and Reasoning its Flip in Conversation (EDiReF)

We present the first shared task on Semantic Textual Relatedness (STR). While earlier shared tasks primarily focused on semantic similarity, we instead investigate the broader phenomenon of semantic relatedness across 14 languages: Afrikaans, Algerian Arabic, Amharic, English, Hausa, Hindi, Indonesian, Kinyarwanda, Marathi, Moroccan Arabic, Modern Standard Arabic, Punjabi, Spanish, and Telugu. These languages originate from five distinct language families and are predominantly spoken in Africa and Asia -- regions characterised by the relatively limited availability of NLP resources. Each instance in the datasets is a sentence pair associated with a score that represents the degree of semantic textual relatedness between the two sentences. Participating systems were asked to rank sentence pairs by their closeness in meaning (i.e., their degree of semantic relatedness) in the 14 languages in three main tracks: (a) supervised, (b) unsupervised, and (c) crosslingual. The task attracted 163 participants. We received 70 submissions in total (across all tasks) from 51 different teams, and 38 system description papers. We report on the best-performing systems as well as the most common and the most effective approaches for the three different tracks.

SemEval Task 1: Semantic Textual Relatedness for African and Asian Languages

This paper presents the results of the SHROOM, a shared task focused on detecting hallucinations: outputs from natural language generation (NLG) systems that are fluent, yet inaccurate. Such cases of overgeneration put in jeopardy many NLG applications, where correctness is often mission-critical. The shared task was conducted with a newly constructed dataset of 4000 model outputs labeled by 5 annotators each, spanning 3 NLP tasks: machine translation, paraphrase generation and definition modeling. The shared task was tackled by a total of 58 different users grouped in 42 teams, out of which 26 elected to write a system description paper; collectively, they submitted over 300 prediction sets on both tracks of the shared task. We observe a number of key trends in how this approach was tackled---many participants rely on a handful of model, and often rely either on synthetic data for fine-tuning or zero-shot prompting strategies. While a majority of the teams did outperform our proposed baseline system, the performances of top-scoring systems are still consistent with a random handling of the more challenging items.

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Pollice Verso at SemEval-2024 Task 6: The Roman Empire Strikes Back

Similar lecture

The Benefits of Being Uncertain: Perplexity as a Signal for Naturalness in Multilingual Machine Translation