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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>HALE Lab NITK at Touché 2024: A Hybrid Approach for Identifying Political Ideology and Power in Multilingual Parliamentary Speeches</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Sevitha Simhadri</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Mauli Mehulkumar Patel</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sowmya Kamath S.</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Information Technology, National Institute of Technology Karnataka</institution>
          ,
          <addr-line>Surathkal, Mangalore 575025</addr-line>
          ,
          <country country="IN">India</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2024</year>
      </pub-date>
      <abstract>
        <p>In this article, an approach to determine the political views and stances of speakers for identifying whether they support or oppose the government in parliamentary discussions is presented. The work was carried out as part of the Touché 2024 Task 2, “Ideology and Power Identification in Parliamentary Debates”. Towards this, two systems were developed, the first employs traditional machine learning methods with TF-IDF embeddings, while the second utilizes advanced NLP techniques with the LASER encoder for multilingual embeddings. Both systems incorporate standard preprocessing techniques and also integrates a variety of models, after which a voting classifier is used to combine the predictions from both approaches. Experiments revealed that this comprehensive framework efectively addresses the complexities and nuances of political discourse, providing valuable insights into speakers' ideologies and governing statuses within parliamentary debates.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Parliamentary Debates</kwd>
        <kwd>Governing Status</kwd>
        <kwd>Natural Language Processing</kwd>
        <kwd>Multilingual Embeddings</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In recent years, analyzing parliamentary debates has become a crucial area of study in political science
and natural language processing (NLP). Understanding speakers’ political ideologies and governing
statuses in these debates can ofer profound insights into legislative processes and power dynamics.
The Touché 2024 Task 2, “Ideology and Power Identification in Parliamentary Debates ”, addresses these
analytical challenges, inviting participants to develop systems that accurately identify parliamentary
speakers’ political stances and leadership roles [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. This task is significant because it advances the
ifeld of NLP and provides practical tools for political analysts and researchers. The Hale Lab team
participated in this task to contribute to developing these analytical tools. By identifying the underlying
ideologies and power structures in parliamentary debates, it is possible to understand better how
political narratives are constructed and conveyed, thus ofering a deeper understanding of the legislative
process and political communication.
      </p>
      <p>In this paper, we cover both tasks; first, we provide a high-level overview of the first task and then
detail our strategy. The same strategy is used for the second task, which is described subsequently.
Lastly, we will highlight our primary contributions and conclusions, along with suggestions for future
work, to wrap up the paper.</p>
      <p>The paper is organized as follows: Section 2 describes the related work in this area; Section 3 outlines
the competition details; Section 4 provides an in-depth explanation of our approach; Section 5 discusses
our main findings; and finally, Section 6 draws conclusions and suggests directions for future research.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Literature Survey</title>
      <p>
        Political viewpoint identification study encompasses a wide range of approaches and perspectives that
are intended to help interpret the intricacies of political debate. In order to gain a clear understanding
of who is powerful and influential in political systems without conducting any practical experiments,
Abercrombie and Batista-Navarro [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] worked on the sentiment and position analysis of the parliamentary
structure. In order to reduce ambiguity and make biases in textual data across the political spectrum
more understandable, Doan and Gulla (2022) [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] developed bias learning techniques. In a similar
vein, they developed a language model for Scandinavian languages[
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] and tested it using political
datasets. Preot¸iuc Pietro et al. (2017)[
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], in contrast, provided a multimodal approach that incorporates
ifne-grained ideology labels from surveys together with linguistic features including unigrams, LIWC,
Word2Vec themes, and sentiment analysis.
      </p>
      <p>Automatic political orientation prediction using social media postings has been studied by Pietro et
al. (2017), and it has shown to be rather successful in diferentiating between openly avowed liberals
and conservatives in the US. Through the usage of language on Twitter, they sought to identify user
groups that were politically involved and to develop an improved model that could predict the political
ideology of users who are not visible.</p>
      <p>Multi-task learning(MTL) was investigated by Barnes et al. (2019)[6]as a means of integrating external
knowledge into neural networks for sentiment analysis. A straightforward method for identifying
ideological learnings in documents based on sentiment expressions toward various topics was presented
by Bhatia and P (2018)[7].</p>
      <p>The study conducted by Ahmadalinezhad and Makrehchi (2018)[8] centered on identifying points
of agreement and disagreement in political discourse. The importance of identifying agreement and
disagreement in political speech is emphasized in their abstract, which also presents their work as a
contribution to the social and cultural modeling field.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Overview of Tasks and Dataset</title>
      <sec id="sec-3-1">
        <title>3.1. Task Definition</title>
        <p>The task consists of two sub-tasks on identifying two important aspects of a speaker in parliamentary
debates (a) Sub-Task 1: Given a parliamentary speech in one of several languages, identify the ideology
of the speaker’s party, and (b) Sub-Task 2: Given a parliamentary speech in one of several languages,
identify whether the speaker’s party is currently governing or in opposition.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Dataset specifics</title>
        <p>The dataset for this task is provided from ParlaMint [9], a multilingual corpus of parliamentary debates.
The data is curated to minimize potential confounding variables, such as speaker identity, to ensure a
balanced and unbiased dataset. The dataset is provided as tab-separated text files with the fields like, id
(a unique ID for each text), speaker (a unique ID for each speaker, multiple speeches from the same
speaker may be included), sex (the binary/biological sex of the speaker, which can be Female, Male, or
Unspecified/Unknown), text (the transcribed text of the parliamentary speech, which may include line
breaks and special sequences), text_en (automatic translation of the text to English. This field may be
empty for English speeches or for some non-English speeches where the translation is unavailable), label
(a binary/numeric label indicating political orientation [0 for left, 1 for right] or power identification [1
for opposition, 0 for coalition/governing party]). The training data encompasses parliamentary speeches
from 28 countries for the political orientation task and 25 countries for the power identification task.
The test files will have the same fields except for the label. A sample dataset for a single country (e.g.,
Latvia) for both sub-task 1 (political orientation) and sub-task 2 (power identification) is illustrated in Fig.
1a and 1b.</p>
        <p>(a) Sub-Task 1 (Political Orientation)
(b) Sub-Task 2 (Power Identification)</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. System Overview</title>
      <sec id="sec-4-1">
        <title>4.1. Data Preprocessing</title>
        <p>Before feeding text data into either system, the following preprocessing steps are performed to improve
the quality of the analysis. First, the text is broken down into individual words or meaningful units,
a process known as tokenization. Next, common words that don’t contribute to sentiment analysis,
such as “the”, “a”, and “an” are eliminated using language-specific stopword lists. Finally, words may be
reduced to their base form (lemma) to improve consistency, a process called lemmatization, although
this step is optional and not necessary for all languages.</p>
        <p>Various language-specific libraries and tools cater to a wide range of languages, facilitating text
analysis and processing tasks. SpaCy [10] supports languages such as Catalan, Croatian, Danish, Dutch,
English, Finnish, French, German, Greek, Italian, Polish, Portuguese, Romanian, Russian, Slovenian,
Spanish, Swedish, and Ukrainian. NLTK [11] provides robust support for languages including Czech,
Danish, Dutch, English, Estonian, Finnish, French, German, Greek, Italian, Polish, Portuguese, Russian,
Slovenian, Spanish, Swedish, and Turkish. Additionally, StanfordNLP [12] specializes in Bulgarian,
Croatian, Serbian, and Slovenian. These tools are essential for preprocessing, analyzing, and understanding
text across diverse linguistic contexts, enhancing the capability of NLP applications worldwide.</p>
      </sec>
      <sec id="sec-4-2">
        <title>4.2. Approach 1: Text Vectorization using TF-IDF</title>
        <p>After preprocessing, the textual data is transformed using the Term Frequency-Inverse Document
Frequency (TF-IDF) method [13]. TF-IDF converts text into numerical features by assessing word
frequency and importance across documents. This transformation is crucial for identifying ideological
leanings within parliamentary speeches and distinguishing whether a speaker represents an opposition
or governing party. The implementation of TF-IDF in this project is pivotal for analyzing parliamentary
speeches, as it emphasizes words that are distinctive within specific documents yet less common across
the entire corpus. This approach enhances the understanding of the content and context of individual
speeches, facilitating nuanced analysis of political discourse.</p>
        <p>TF-IDF plays a crucial role in ideology detection by identifying key terms and phrases indicative of
leftleaning or right-leaning ideologies. Terms frequently associated with specific ideological stances receive
higher TF-IDF scores, enabling machine learning models to efectively diferentiate between speeches
with contrasting ideological orientations. Additionally, TF-IDF assists in distinguishing speeches from
opposition members versus those representing governing parties. By analyzing the prevalence and
importance of specific terms, TF-IDF reveals linguistic patterns characteristic of opposition or governing
party discourse.</p>
      </sec>
      <sec id="sec-4-3">
        <title>4.3. Approach 2: Multilingual Sentence Embeddings</title>
        <p>Instead of employing the TF-IDF method for text embedding, the LASER (Language-Agnostic SEntence
Representations) encoder was utilized to transform the textual data. Developed by Facebook, LASER [14]
is designed to enhance performance by providing highly efective multilingual sentence representations.
This toolkit supports over 90 languages written in 28 diferent alphabets, embedding all languages
jointly in a unified space rather than requiring separate models for each language. This capability makes
LASER particularly advantageous for zero-shot transfer learning (Fig. 3), where a model trained on one
language can generalize to others, including low-resource languages. The LASER encoder employs a
ifve-layer bidirectional Long Short-Term Memory (BiLSTM) network (Fig. 4) to generate a fixed-size
vector representation of input sentences in 1,024 dimensions. This high-dimensional vector is derived
by max-pooling over the final states of the BiLSTM, ensuring that the embeddings encapsulate the
semantic essence of sentences, irrespective of their written language. This universal, language-agnostic
sentence embedding simplifies the comparison of sentence representations and supports their direct
application in diverse classifiers.</p>
      </sec>
      <sec id="sec-4-4">
        <title>4.4. Prediction Models</title>
        <p>Features extracted from both TF-IDF and LASER encodings are utilized in various traditional machine
learning models to classify speeches based on ideological orientation and political afiliation. The models
employed include Logistic Regression, Support Vector Classifier (SVC), Naive Bayes, Random Forest
Classifier, Gradient Boosting Classifier, and XGBoost Classifier. These models leverage the numerical
features derived from the embeddings to efectively categorize the speeches, distinguishing between
diferent ideological leanings and political afiliations.</p>
        <p>To address the limitations encountered with traditional machine learning models, advanced deep
learning architectures were incorporated into the classification process. A multi-layered LSTM [ 15]
architecture with an embedding layer was utilized to convert inputs into denser representations.
Regular dropout and recurrent dropouts were integrated to ensure the model’s ability to generalize well.
Additionally, a Simple Neural Network with two hidden layers was employed, featuring input layers,
multiple hidden layers with ReLU activations, and dropout layers. Furthermore, a Voting Classifier was
employed, combining the predictions of all the above classifiers—including the ML models, LSTM, and
Simple Neural Network—to enhance classification accuracy.</p>
      </sec>
      <sec id="sec-4-5">
        <title>4.5. Integrating BERT</title>
        <p>In an attempt to further enhance performance, we considered integrating BERT [16], a
transformerbased model known for its contextual word embeddings. However, due to the demanding computational
requirements and the unsatisfactory results obtained during the training phase, we decided to terminate
the integration of BERT into the classification pipeline. While BERT holds promise for improving
classification accuracy by capturing important contextual information, our preliminary experimentation
indicated that computational infrastructure constraints and performance limitations made it impractical
for deployment in our project’s context. Additionally, as BERT is language-specific and multilingual
versions of BERT were not readily available, we halted further testing and deployment of BERT.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Experimental Results</title>
      <p>As the leaderboard results are yet to be released, we are currently comparing our outcomes solely with
the baseline. In the Touché 2024 Task 2, our team, Hale Lab, explored two distinct approaches. Both
strategies demonstrated remarkable performance enhancements compared to the baseline across a
range of metrics. In System 1, we achieved an F1 score of 0.6055 for political orientation and 0.6724
for power identification. Similarly, System 2 yielded promising results with an F1 score of 0.6154 for
political orientation and 0.6983 for power identification, as shown in Table 1. When compared to the
baseline, our methodologies consistently showcased improved performance metrics, including precision,
recall, and F1 scores, across various countries. These outcomes underscore the efectiveness of our
approaches in accurately deciphering political ideologies and power dynamics within parliamentary
debates.</p>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion and Future Work</title>
      <p>In this paper, the various approaches designed for addressing the Touché 2024 Task 2 requirements,
focusing on the identification of political ideologies and power structures within parliamentary
debates, were presented. Our methodology involved leveraging diverse feature sets, including linguistic,
contextual, and speaker-related features, and applying advanced classification models to accurately
detect the political orientation and power status of speakers. Despite the complexities introduced by
the multilingual and heterogeneous nature of the dataset, our experiments yielded significant insights
into the ideological and power dynamics of parliamentary discourse. These findings underscore the
importance of robust preprocessing and the integration of various linguistic and contextual features to
enhance model performance.</p>
      <p>As part of extended work, we plan to further optimize our model to specifically identify the
relationships between speeches, to determine which speeches are replies to others. This relational context is
currently missing in the dataset but is crucial for a comprehensive understanding of parliamentary
debates. Techniques such as dialogue act recognition and sequential modeling to map the conversational
lfow between speeches will also be explored. Including more languages and legislative contexts, and
expert feedback, to enhance the generalizability of our models.</p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgments</title>
      <p>We extend our sincere gratitude to the Touché Lab for providing us with the opportunity to participate
in this challenging task and for their support throughout the process. Special thanks to Çağrı Çöltekin
for his invaluable assistance.
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