<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>DEMA²IN at Touché: Salient Events Extraction for Ideology and Power Identification in Parliamentary Debates</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Benjamin Callac</string-name>
          <email>benjamin.callac@enib.fr</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Anne-Gwenn Bosser</string-name>
          <email>bosser@enib.fr</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Florence Dupin de Saint-Cyr</string-name>
          <email>dupin@irit.fr</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Eric Maisel</string-name>
          <email>maisel@enib.fr</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>CLEF 2025 Working Notes</institution>
          ,
          <addr-line>9 - 12</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Ecole Nationale d'Ingénieurs de Brest, Lab-STICC</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Université Paul Sabatier</institution>
          ,
          <addr-line>IRIT</addr-line>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <abstract>
        <p>Parliamentary debates are a rich source of information for analyzing political ideologies and power structures. In this work, we explore an approach to train a model with minimal text input, by focusing on the extraction of salient events from transcribed speeches from the ParlaMint corpora. Rather than relying on full-text inputs, we investigate whether a distilled representation of meaningful events is suficient to train classifiers for downstream political tasks. Although the reduced input leads to performance slightly below baseline this aligns with expectations given the minimal training data.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Event Extraction</kwd>
        <kwd>NLP</kwd>
        <kwd>Political Debates</kwd>
        <kwd>CLEF</kwd>
        <kwd>Touché</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>Parliamentary debates play a critical role in the life of a democracy. They require knowledge of the
political landscape to accurately interpret the ideologies and power dynamics expressed by political
actors. As such, analyses of political discourse often rely on manually reviewing the data, which can be
both time-consuming and limited in scope.</p>
      <p>With the advent of machine learning and large language models, the field of natural language
processing has had tremendous advancements in recent years. Notably, in the fields of sentiment
analysis and text classification, comprising the tasks of extracting the meaning of a document, these
technologies have achieved impressive performance levels by learning complex patterns and contextual
nuances from vast corpora.</p>
      <p>
        In this context, Touché at CLEF suggests a task aiming at the identification of power and orientation
based on parliamentary speeches [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
      </p>
      <p>Our approach to this task is to verify whether or not summarizing a speech and extracting the events
related within keeps this type of classification task robust. Rather than relying on explicit indicators of
stance, manner of speech, or action proposals, our method aims to capture the underlying description of
a situation and events from political actors. This approach ofers a more abstract way to analyze political
discourse, emphasizing the events that are reported rather than how they are framed rhetorically. As
such our evaluation aims to assess whether this event-centered summarization retains meaningful
information for a model to distinguish between ideological orientations and between the party in power
or the opposition.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Dataset</title>
      <p>Touché [2] provides a dataset to work with on this task, it is composed of a selection of speeches
from the ParlaMint corpora [3]. The dataset is comprised of parliamentary speeches in 29 European
languages and has been modified to exclude any information about parties and speakers susceptible to
aid in the identification of the labels we are trying to predict. Each diferent language is contained in its
own file, all the relevant labels, however are combined in a single file. The dataset file is composed of
the following fields :
id is a unique (arbitrary) ID for each text.
speaker is a unique (arbitrary) ID for each speaker There may be multiple speeches from the same
speaker.
sex is the (binary/biological) sex of the speaker. This information is collected from varying sources
(typically data published by the respective parliament), and in some cases it may be unspecified
or unknown.
text is the transcribed text of the parliamentary speech. Real examples may include line breaks, and
other special sequences escaped or quoted.
text_en is an automatic English translation of the corresponding text. This field may be empty (obviously)
for speeches in English, but the translations may be missing for a small number of non-English
speeches as well.
orientation is the binary/numeric label ( 0 is left and 1 is right). Orientation labels are based on Wikipedia.
power is the binary label for power role (0 is opposition, 1 is coalition), this information is based on the
information provided by the ParlaMint contributors. This value is not always present, either
due to parliamentary systems with no defined coalition/opposition, or unknown orientation
information for some speakers (e.g., PMs with no party afiliation). Missing values are indicated
as ‘NA’.
populism is a populism index based on multiple expert surveys (to increase the coverage). We focus on
a particular dimension of populism in this task: the position of the party of the speaker in
populist - pluralist spectrum. This is measured on a 4-point ordinal scale (1: Strongly Pluralist,</p>
      <sec id="sec-2-1">
        <title>2: Moderately Pluralist 3: Moderately Populist, 4: Strongly Populist). Not all values are present in all parliaments. Many parties/speakers are not covered by the data, and some values are missing due to failure to match the survey identifies/names and ParlaMint identifiers. Missing values are indicated as ‘NA’.</title>
        <p>We focus solely on speeches from the British Parliament. This allowed us to obtain a baseline of our
system’s performance without having to factor in automatic English translations while still working on
enough data for our investigation.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. System overview</title>
      <p>In this section, we describe how we processed the data before feeding it to a model for fine-tuning.
For the model we opted to use Mistral-7b v0.2 Instruct. Approaches in past editions [4] of this task
tried to preprocess and augment the dataset as much as possible to give models more context to make
predictions out of, with great results. In our system however we aim to verify whether or not subtracting
elements to only keep the key events described in the speeches is enough to make accurate predictions.</p>
      <p>We largely base this work on CALLMSAE by [5] in which, via cascading LLM prompting, they are
able to build causal graphs describing the events and their relations — hierarchical, temporal or causal.
We found however that the generation of causal graphs did not lead good results on a large part of the
data and ended up focusing on salient events generation.</p>
      <sec id="sec-3-1">
        <title>3.1. Data processing</title>
        <p>As described in [5] we first prompt a LLM to summarize a speech, because LLMs, much as humans,
tend to only relate the most relevant events when asked to summarize a document.</p>
        <sec id="sec-3-1-1">
          <title>Input data</title>
        </sec>
        <sec id="sec-3-1-2">
          <title>Summary</title>
          <p>generation</p>
        </sec>
        <sec id="sec-3-1-3">
          <title>Salient events identification 70%</title>
          <p>30%</p>
        </sec>
        <sec id="sec-3-1-4">
          <title>Training</title>
        </sec>
        <sec id="sec-3-1-5">
          <title>Validation</title>
        </sec>
        <sec id="sec-3-1-6">
          <title>Model for classification</title>
          <p>Then we instruct another LLM to extract the events from this summary: the event generation is
often lacking events. To prevent this issue and to get the most from the summarized text we elected
to run this process multiple times. The results of these multiple processing are then aggregated with
another prompt asking to combine all the diferent lists while eliminating duplicates and entries with
semantically close meanings. During our diferent attempts we observed the final event list would not
change substantially when combining the results of more than 4 diferent promptings, so that is the
number of total passthroughs we finally opted to use.</p>
          <p>Prompt 2 - Salient Event extraction
A structured event is something that happened as described in the text. A
structured event is represented as a tuple, which consists of actors, a
trigger, and objects. Could you list all the structured events in the
following article? Example: 1. (John; married; Alice). 2. (Alice; was
hired; by Google). Format the results in between parenthesis as in the
example. Article: """ summary """
Prompt 3 - Event list aggregation
You are a helpful assistant. Given a list of events if there are semantically
similar event descriptions, choose the most accurate and typo-free version
of the event, do not lump details together. Then, return the events list
with no duplicate using the following format: Example: 1. (John; married;
Alice) 2. (Alice; was hired; by Google) 3. (John; was hired; by Google)
Events : """ events_string ""“</p>
          <p>For the most part of the data, following this processing gives us a relevant event list of what transpires
from the speech. However with the sheer amount of data, there is no way to know for sure if there are
important events missing from the lists. Also something that we do not account for in our approach is
the possibility of hallucinations from the LLM.</p>
        </sec>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Classification process</title>
        <p>Classification was made by fine-tuning the pre-trained BERT base for all the diferent labels to predict.
To account for the two diferent tasks that are the identification of power and identification (a multilabel
classification task with binary output) and the populism identification (a single label classification
task with output ranging 4 values) we trained two separate classifiers. The first classifier performs a
multi-label classification on both power and orientation, while the second one performs a single label
classification task on populism only. Both classifiers are based on the same architecture and use identical
hyperparameters except for the problem type. We use the salient events data obtained previously for
this fine-tuning step. Each input corresponds to a list of events represented as a single string and is
tokenized using the Standard BERT tokenizer with truncation and padding up to 128 tokens. For the
multi-label setup, the corresponding binary labels were encoded into a multi-hot vector of length two
(orientation, power). We then trained a classification head on top of the BERT base encoder using
the Hugging Face AutoModelForSequenceClassification. We do the fine-tuning using the Hugging
Face Trainer API. Ultimately, training was conducted on GPU with a batch size of 8, a learning rate
of 2 × 10− 5 for 5 epochs. Training and validation were done using an 80/20 split. For inference, we
applied our fine-tuned multi-label BERT model to the separate test set consisting of unseen speeches
represented by extracted salient events. Each data point was passed through a tokenization pipeline
and fed into the model in batches. The multi-label classifier produced independent sigmoid-activated
probability scores for each label while the single label classifier produced logits for the four populism
classes, to which we applied an argmax operation to assign the most likely class label to each event list.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Parameters</title>
        <p>Because of the large amount of data to process through multiple LLMs in a downstream task, we put
a certain amount of efort in making the processing faster. We used VLLM to load the models and
make inferences with, prompting the model in batches of 5 prompts at a time. The default sampling
parameters were set at .3 for the temperature and 512 for the maximum tokens. Although, this last value
changes depending on the prompt, we used a maximum of 300 tokens for the summary generation. We
do believe we could have gone lower for the amount of tokens but that would have meant taking the
risk of impacting the quality of the output without being able to observe it directly.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Results</title>
      <p>In this section we shall review and be critical of the results we obtained for the submission on the
Touché test data.</p>
      <p>During the validation phase, we obtained the metrics shown in table 1. We observe right at the
validation that while the F1-score is not terribly low, the accuracy however is barely better than a
coin-flip.</p>
      <sec id="sec-4-1">
        <title>Metric</title>
      </sec>
      <sec id="sec-4-2">
        <title>Loss</title>
      </sec>
      <sec id="sec-4-3">
        <title>Accuracy</title>
      </sec>
      <sec id="sec-4-4">
        <title>F1-score</title>
      </sec>
      <sec id="sec-4-5">
        <title>Value 0.554 0.592 0.796</title>
        <p>As we only used speeches in the English language, we can only match our results with the baseline
on the very same data. The baseline is a simple system, vectorizing the documents with TF-IDF and
making predictions through linear regression. We compare the results of our system with the baseline
results in the tables 2, 3, 4.</p>
      </sec>
      <sec id="sec-4-6">
        <title>Team Precision Orientation baseline 0.77 dema2in (ours) 0.727</title>
      </sec>
      <sec id="sec-4-7">
        <title>Recall Orientation 0.771 0.724</title>
      </sec>
      <sec id="sec-4-8">
        <title>F1 Orientation 0.77 0.719</title>
      </sec>
      <sec id="sec-4-9">
        <title>Team Precision Power baseline 0.784 dema2in (ours) 0.737</title>
      </sec>
      <sec id="sec-4-10">
        <title>Recall Power F1 Power 0.762 0.766 0.727 0.729</title>
        <p>In these results we observe our model is barely below the baseline in terms of F1-Score except for
populism. This outcome, while slightly underwhelming considering the heavy preprocessing applied
to the data was anticipated due to the nature of the data we fine-tune the model with. A substantial
amount of potentially useful data for the model to train with was excluded, thus limiting to the broader
context that could have contributed to better performances. Although the subset of data used to train
the model was easier for humans to understand, it lacked information that could have been present in
the entire texts.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Discussion</title>
      <p>There are limitations in this experiment. It would have been interesting to use the same approach
using diferent models to see how they compare, especially considering the numerous powerful models
available. In the future we would like to compare the results using Chat-GPT, BERT, RoBERTa, to see if
they yield diferent results. Furthermore, the evaluation setup did not allow for a thorough analysis of
the impact of each stage in the pipeline — summarization quality, the precision of event extraction, and
the influence of lost contextual information. These components likely have a significant cumulative
efect on the final classification performance, but their individual contributions were not quantified.
Future developments could benefit from a more detailed evaluation of each component in the pipeline,
as well as maybe more advanced summarization and event extraction methods.</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgments</title>
      <p>Many thanks to my supervisors Anne-Gwenn Bosser, Florence Dupin de Saint-Cyr and Eric Maisel
who have trusted me in trying out this approach. This work was supported by the French Defence
Innovation Agency (AID) and the Region Bretagne.</p>
    </sec>
    <sec id="sec-7">
      <title>Declaration on Generative AI</title>
      <p>During the preparation of this work, the author(s) used Chat-GPT-4o in order to: Grammar and spelling
check. Abstract drafting. After using these tool(s)/service(s), the author(s) reviewed and edited the
content as needed and take(s) full responsibility for the publication’s content.
in Computer Science, Springer, Berlin Heidelberg New York, 2023, pp. 236–241. doi:10.1007/
978-3-031-28241-6_20.
[2] J. Kiesel, Ç. Çöltekin, M. Gohsen, S. Heineking, M. Heinrich, M. Fröbe, T. Hagen, M. Aliannejadi,
T. Erjavec, M. Hagen, M. Kopp, N. Ljubešić, K. Meden, N. Mirzakhmedova, V. Morkevičius, H. Scells,
I. Zelch, M. Potthast, B. Stein, Overview of Touché 2025: Argumentation Systems, in: J. C.
de Albornoz, J. Gonzalo, L. Plaza, A. García Seco de Herrera, J. Mothe, F. Piroi, P. Rosso, D. Spina,
G. Faggioli, N. Ferro (Eds.), Experimental IR Meets Multilinguality, Multimodality, and Interaction.
16th International Conference of the CLEF Association (CLEF 2025), Lecture Notes in Computer
Science, Springer, Berlin Heidelberg New York, 2025.
[3] Ç. Çöltekin, M. Kopp, K. Meden, V. Morkevicius, N. Ljubešić, T. Erjavec, Multilingual Power
and Ideology Identification in the Parliament: A Reference Dataset and Simple Baselines, 2024.
doi:10.48550/arXiv.2405.07363. arXiv:2405.07363.
[4] O. Palmqvist, J. Jiremalm, P. Picazo-Sanchez, Notebook for the Touch{é} Lab at CLEF 2024 (????).
[5] X. Tan, Y. Zhou, G. Pergola, Y. He, Cascading large language models for salient event graph
generation, in: L. Chiruzzo, A. Ritter, L. Wang (Eds.), Proceedings of the 2025 Conference of the
Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language
Technologies (Volume 1: Long Papers), Association for Computational Linguistics, Albuquerque,
New Mexico, 2025, pp. 2223–2245. URL: https://aclanthology.org/2025.naacl-long.112/.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>M.</given-names>
            <surname>Fröbe</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Wiegmann</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Kolyada</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Grahm</surname>
          </string-name>
          ,
          <string-name>
            <given-names>T.</given-names>
            <surname>Elstner</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Loebe</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Hagen</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Stein</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Potthast</surname>
          </string-name>
          ,
          <article-title>Continuous Integration for Reproducible Shared Tasks with TIRA.io</article-title>
          , in: J.
          <string-name>
            <surname>Kamps</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          <string-name>
            <surname>Goeuriot</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          <string-name>
            <surname>Crestani</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          <string-name>
            <surname>Maistro</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          <string-name>
            <surname>Joho</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          <string-name>
            <surname>Davis</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          <string-name>
            <surname>Gurrin</surname>
            ,
            <given-names>U.</given-names>
          </string-name>
          <string-name>
            <surname>Kruschwitz</surname>
            ,
            <given-names>A</given-names>
          </string-name>
          . Caputo (Eds.),
          <source>Advances in Information Retrieval. 45th European Conference on IR Research (ECIR</source>
          <year>2023</year>
          ), Lecture Notes
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>