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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>Conference and Labs of the Evaluation Forum, September</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>SSN-NLP at CheckThat! 2024: Assessing the Check-Worthiness of Tweets and Debate Excerpts Using Traditional Machine Learning and Transformer Models</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Sanjai Balajee Kannan Giridharan</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sanjjit Sounderrajan</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>B Bharathi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nilu R. Salim</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Sri Sivasubramaniya Nadar College of Engineering</institution>
          ,
          <addr-line>Chennai, Tamil Nadu</addr-line>
          ,
          <country country="IN">India</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2024</year>
      </pub-date>
      <volume>0</volume>
      <fpage>9</fpage>
      <lpage>12</lpage>
      <abstract>
        <p>The rapid spread of misinformation on social media necessitates eficient methods for determining whether claims in tweets or transcriptions warrant fact-checking. Traditional approaches rely on professional fact-checkers or human annotators, which are labor-intensive and time-consuming. This paper presents automated methods using machine learning and natural language processing to streamline check-worthiness estimation. We leveraged various techniques, including transformer models, to capture contextual nuances and improve prediction accuracy. Our work focused solely on the English language dataset, and our methods ranked 13th on the leaderboard. Our ifndings demonstrate the efectiveness of these automated methods, highlighting their potential to significantly enhance the eficiency of fact-checking systems and promote information integrity in digital communication.</p>
      </abstract>
      <kwd-group>
        <kwd>Check-Worthiness Estimation</kwd>
        <kwd>Fact-Checking Automation</kwd>
        <kwd>Natural Language Processing (NLP)</kwd>
        <kwd>PoS Tagging</kwd>
        <kwd>Machine Learning Classifiers</kwd>
        <kwd>Transformer Models</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In today’s digital age, the rapid dissemination of information through social media platforms and online
forums has led to an increase in the spread of misinformation and fake news. Addressing this challenge
requires efective methods for identifying claims that warrant further investigation and fact-checking.
Traditionally, the task of check-worthiness estimation has relied on professional fact-checkers or human
annotators who assess the verifiability and potential harm of claims [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. However, these manual
processes are labor-intensive and time-consuming, highlighting the need for automated solutions.
      </p>
      <p>
        Our research aims to automate the task of check-worthiness estimation by leveraging machine
learning and natural language processing techniques. We utilize a multi-genre dataset comprising
tweets and transcriptions to evaluate the efectiveness of diferent models across various linguistic and
cultural contexts [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. By employing advanced algorithms and transformer models, we aim to enhance
the accuracy and eficiency of check-worthiness estimation.
      </p>
      <p>
        In this paper, we provide a comprehensive overview of the check-worthiness estimation task,
emphasizing its significance in combating misinformation and promoting information integrity. We discuss
the methodologies employed in existing approaches, including traditional machine learning algorithms
and transformer-based models, and propose avenues for future research and model development. Our
contributions seek to advance automated fact-checking systems that can efectively identify and flag
potentially misleading or false claims in textual content, fostering a more informed and trustworthy
information ecosystem [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Work</title>
      <p>
        The task of check-worthiness estimation has gained considerable attention, particularly through the
CLEF CheckThat! lab series. These eforts address the challenges of identifying claims in social media
and other textual sources that warrant fact-checking. Nakov et al. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] investigate the identification of
check-worthy claims amidst the COVID-19 infodemic and the detection of fake news. Their research
provides an in-depth examination of techniques for spotting misleading information on social media
platforms.
      </p>
      <p>
        The CLEF-2022 CheckThat! lab introduced additional tasks and datasets aimed at enhancing the
automatic identification and verification of claims [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. This included Task 1, which focused on identifying
relevant claims in tweets [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>
        Advancements have been made by incorporating machine learning and deep learning models. For
example, Support Vector Machines (SVM) [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] and Random Forest [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] have been utilized efectively in
classification tasks. Passive-Aggressive Classifiers have shown promise in fake news detection [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <p>
        Transformer-based models have significantly advanced check-worthiness estimation. BERT [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ],
RoBERTa [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ], XLM [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], and DeBERTa [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] have demonstrated high efectiveness in understanding
complex linguistic patterns. Additionally, ensemble learning techniques have been identified as promising
for improving model performance by combining the strengths of various algorithms [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ].
      </p>
      <p>These works collectively highlight the importance of leveraging machine learning and natural
language processing techniques to automate the detection of claims that warrant fact-checking, thus
contributing to the broader efort of combating misinformation and enhancing the reliability of
information disseminated through social media.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Experiment Setup</title>
      <sec id="sec-3-1">
        <title>3.1. Dataset Description</title>
        <p>In this study, we utilized a dataset encompassing four languages: English, Spanish, Arabic, and Dutch,
as released by the CLEF CheckThat! organizers. The dataset comprises sentence IDs, text snippets
extracted from tweets, debates, or speech transcriptions, and a class label indicating whether a claim
is check-worthy (Yes) or not (No). Table 1 presents the distribution of the dataset across the four
languages.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Dataset Preprocessing</title>
        <p>In this section, we describe the data preprocessing steps undertaken to prepare the dataset for training
and evaluation. The preprocessing pipeline consists of several key stages, including text cleaning,
tokenization, stopword removal, punctuation removal, URL removal, spelling correction, part-of-speech
(POS) tagging, dependency parsing, and feature extraction.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Feature Extraction Methods</title>
        <p>The feature extraction process begins with the linguistic analysis of text data using natural language
processing (NLP) techniques. Initially, the input sentences are subjected to part-of-speech (POS) tagging
and dependency parsing. POS tagging assigns grammatical categories to each word, distinguishing
between parts of speech such as nouns, verbs, adjectives, etc., while dependency parsing reveals the
syntactic relationships between words, delineating the structure of the sentence through dependencies
like subject-verb or modifier-modified relationships.</p>
        <p>Figure 1 shows the dependency relations</p>
        <p>Subsequently, these syntactic analyses are leveraged to extract relevant features capturing the
linguistic structure of the text. Feature extraction involves converting the sequences of POS tags and
dependency labels into meaningful representations. This process encompasses aggregating POS tags
into vectors, capturing the distribution of diferent grammatical categories in the text, and encoding
dependency relationships into feature vectors, emphasizing crucial syntactic dependencies.</p>
        <p>Finally, the feature vectors are combined with sentence embeddings generated using a pre-trained
transformer model such as Sentence-BERT. These embeddings capture the semantic content of the
text at the sentence level, enabling the extraction of high-level semantic features. This combination
allows for a richer and more nuanced understanding of the textual data. The combined feature
representation undergoes data scaling to normalize the feature values and dimensionality reduction using
principal component analysis (PCA) to reduce computational complexity and potentially enhance model
performance.The resulting reduced-dimensional feature vectors serve as input to machine learning
models.</p>
        <p>Figure 2 illustrates the feature extraction pipeline.</p>
      </sec>
      <sec id="sec-3-4">
        <title>3.4. Basic ML Models</title>
        <p>In our experiment, we utilized various machine learning models with hyperparameters optimized using
GridSearchCV. The models and their respective hyperparameters are as follows:
• Support Vector Machine (SVM):  = 100,  = 0.02, kernel: rbf.
• Random Forest Classifier : n_estimators=300.
• Logistic Regression:  = 0.1, solver=liblinear.
• XGBoost Classifier : learning_rate=0.1, max_depth=6, n_estimators=1000.
• CatBoost Classifier : depth=5, learning_rate=0.05, iterations=1000.
• K-Nearest Neighbors (KNN): n_neighbors=11, metric=euclidean.</p>
        <p>• Passive Aggressive Classifier :  = 0.01.</p>
        <p>The hyperparameters for each model were tuned using GridSearchCV to ensure optimal performance.</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.5. Transformer Models</title>
        <p>In our experiment, we utilized several transformer models to evaluate their performance on our task.
BERT-base-uncased is the original BERT model developed by Google in 2018. It is a pre-trained
language model that uses a multi-layer bidirectional transformer encoder to generate contextualized
representations of words in a sentence. RoBERTa-base is another variant of BERT developed by
Facebook AI in 2019. It improves upon the original BERT model by using a diferent pre-training
objective and a larger dataset. XLM-RoBERTa-base is a multilingual version of RoBERTa developed
by researchers from the University of Montreal and Facebook AI in 2020. It is trained on a large corpus
of text in multiple languages and can be fine-tuned for specific NLP tasks in any of these languages.
DeBERTa-v3-base is a variant of BERT developed by researchers from Microsoft in 2021. It enhances
BERT by using disentangled attention and ELECTRA-style pre-training, improving eficiency and
performance on downstream tasks. Among these models, DeBERTa-v3-base demonstrated slightly
better performance compared to the others.</p>
        <p>The table shows the maximum sequence length, batch size, and learning rate used for each transformer
model in our experiment (Table 2).</p>
        <p>Model
BERT (bert-base-uncased)
RoBERTa (roberta-base)
XLM-RoBERTa (xlm-roberta-base)
DeBERTa (deberta-v3-base)</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Results</title>
      <p>For the challenge, the macro-average F1-score was employed as the oficial evaluation metric. This
metric calculates the F1-score for each class individually and then computes the average of these scores.</p>
      <p>The organizers provided three datasets for both languages: training, dev-test, and test. All models
were trained using only the training dataset. Refer to the previous section for the hyperparameters
used during training.</p>
      <p>Table 3 summarizes the test F1 scores achieved by the models on the provided test dataset.</p>
      <p>Overall, the transformer models outperformed the traditional machine learning algorithms.
DeBERTav3-base achieved the highest F1-score on the test dataset.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusion</title>
      <p>In this work, we present our participation in CLEF 2024 CheckThat-Lab Task 1: Check-worthiness
Estimation in Text. Our evaluation showed the superiority of transformer models over traditional machine
learning algorithms, as measured by the macro-average F1-score. This highlights the importance of
using advanced transformer-based approaches for natural language processing tasks. Future research
could explore fine-tuning strategies and alternative architectures to improve performance.</p>
      <p>Our team, SSN-NLP, ranked 13th out of 27 teams on the leaderboard with a macro F1-score of 0.706,
using the BERT model. The leaderboard results are summarized in Table 4, showing that
BERT-baseuncased performed better than other models.</p>
      <p>Team Name</p>
      <p>Model
BERT-base-uncased</p>
      <p>F1-score
• Ensemble Methods: Combining multiple models to leverage their individual strengths can
potentially lead to higher accuracy and robustness. Future work could explore various ensemble
techniques, such as stacking, boosting, or voting, to improve overall performance.
• Larger and More Diverse Datasets: The availability of larger and more diverse datasets can
significantly impact the generalizability of the models. Future studies should aim to collect and
utilize datasets that encompass a wider range of topics, languages, and cultural contexts to train
more versatile and robust models.
• Cross-Lingual and Cross-Domain Transfer Learning: Exploring transfer learning techniques
to adapt models trained on one language or domain to other languages or domains can broaden
the applicability of check-worthiness estimation models.</p>
    </sec>
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