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    <article-meta>
      <title-group>
        <article-title>Exploring sentiments in summarization: SentiTextRank, an Emotional Variant of TextRank</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Md. Murad Hossain</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Luca Anselma</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alessandro Mazzei</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer Science, University of Turin</institution>
          ,
          <addr-line>Corso Svizzera 185, 10149 Torino</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2023</year>
      </pub-date>
      <volume>1</volume>
      <fpage>0000</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>English. A summary that aims at preserving the emotions of the original text can be interesting in certain application scenarios, such as in the generation of metareviews, both in academic and commercial domains. TextRank is a well-studied algorithm for automatic extractive summarization. This work introduces SentiTextRank, an emotional variant of TextRank, to enhance the extractive technique for both single-document and multi-document summarization. SentiTextRank incorporates emotions into the summarization process by classifying sentences into the eight emotional categories used in SenticNet. The preliminary evaluation of SentiTextRank yields encouraging results. In particular, our method generates informative summaries composed of sentences that preserve the emotional content of the original document. Italian. Un riassunto che miri a preservare le emozioni del testo originale può essere interessante in alcuni scenari applicativi, come ad esempio nella generazione di meta-recensioni sian nel dominio accademico che in quello commerciale. TextRank è un algoritmo per il riassunto automatico estrattivo molto studiato. Questo lavoro introduce SentiTextRank, una variante emozionale di TextRank, per potenziare la tecnica estrattiva sia per il riassunto di singoli documenti che per il riassunto di documenti multipli: SentiTextRank integra le emozioni nel processo di sintesi, classificando le frasi nelle otto categorie emotive utilizzate in SenticNet. La valutazione preliminare di SentiTextRank produce dei risultati incoraggianti. In particolare, il nostro metodo produce dei riassunti informativi formati da frasi che rispettano il contenuto emozionale del documento originale.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Extractive summarization</kwd>
        <kwd>SentiTextRank</kwd>
        <kwd>emotional variant</kwd>
        <kwd>single and multi-document Summary</kwd>
        <kwd>emotional content</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>important to consider emotions to create summaries that
truly reflect the essence of the source texts.</p>
      <p>In this paper, by incorporating sentiment scoring be- SentiTextRank: Input=Source, Output=
tween sentences, we generate summaries that capture 1. Set compression ratio parameter  between the
the emotional tone and impact of the original text. We source(s) and the final summary  .
believe that exploring this aspect further would lead to 2. Classify sentences of the source(s) into diferent
more comprehensive and efective text summarization SenticNet emotion categories  with  ∈
methods. {joy, admiration, surprise, fear, disgust, anger,
sad</p>
      <p>This paper has two main goals. First, we define a new ness, interest}.
algorithm called SentiTextRank, which is an emotional 3. Generate a summary  for each emotion
variant of TextRank [5]. Second, we provide an initial category  by using TextRank.
evaluation of SentiTextRank by considering two auto- 4. Build  by picking a number of sentences
matic metrics based on content distance. proportional to  from each  maintaining</p>
      <p>Note that modern LLMs showed some abilities in sum- the original sentence order of the source
documarizing texts by using a specific style, with some limi- ment.
tations in producing a summary that is truly extractive.</p>
      <p>Moreover, LLMs showed also a big impact from the point
of view of the required computational resources. We be- 3. Experimental Result and
lieve that the work presented in this paper, that requires Discussion
just few hours to conduct all the experiments, can be
seen as a cheap (in many senses) alternative to the use
of modern expensive (in many senses) LLMs1.</p>
      <p>The paper is structured as follows. In Section 2, we
define the new SentiTextRank algorithm, in Section 3
we report the result of a first experimental evaluation of
the SentiTextRank algorithm and the Section 4 ends the
paper pointing out to work in progress.</p>
      <sec id="sec-1-1">
        <title>In this section, we present the experimental results</title>
        <p>of single-document summarization using two datasets,
the CNN/Daily Mail dataset (CNN) and the DUC2001
single document dataset (D01), as well as the results
of multi-document summarization using two datasets,
the DUC2001 multi-document dataset (MD01) and the
DUC2004 multi-document dataset (MD04).</p>
        <p>The DUC 2001 single document and DUC 2001
Multidocument datasets were collected from the website2 and</p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>2. SentiTextRank: a variant of</title>
      <p>consist of news datasets. For our experiments with single
TextRank accounting for documents, we utilized a sample data set of 54 documents.
emotions The DUC 2004 multi-document summarization dataset3
includes 50 items with multiple files and four reference
TextRank is a popular algorithm for extractive summa- files per item, from which we utilized the first reference
rization which constructs a graph of sentences or words for each item. Additionally, we used the CNN/Daily mail
from a text and assigns scores to each node based on dataset4, where we considered the “highlights” column
their importance in the graph structure. Finally, it ranks as the reference summary. Our experiments were
conthe nodes and selects the top-ranked sentences or words ducted on the first 100 rows of text in the CNN/Daily
as the summary [5]. The TextRank algorithm is based mail dataset. Since the datasets provide just abstractive
on the PageRank algorithm, where the sentences of the gold summaries, in order to provide a fair comparison we
documents play the role of web pages, and a similarity have converted the abstractive summaries into extractive
score plays the role of hyperlink connectivity. Our ap- summaries. This procedure has been proposed in [7, 8].
proach enhances traditional TextRank by incorporating An extractive reference summary should yield the
highemotions. In particular, we categorize sentences of the est Rouge score when compared to the gold abstractive
original source(s) on the basis of emotions using Sentic- summary. As finding the globally optimal subset of
senNet [6]. On the basis of this classification, we obtain a tences that maximize the Rouge score is computationally
number of distinct emotion sets of sentences. The main intractable, we adopt a greedy approach: we iteratively
idea is to build one single final summary by merging in add one sentence at a time to the summary, ensuring that
a selective way the results of TextRank on each one of the Rouge score of the current set of selected sentences
these emotions sets. is maximized in relation to the entire gold summary. We</p>
      <p>So, the proposed SentiTextRank algorithm generates repeat this process until there are no more candidate
senextractive summaries with emphasis on emotion tences that could enhance the Rouge score when added
categories through the following steps:</p>
      <sec id="sec-2-1">
        <title>1We thank an anonymous reviewer for pointing out this point.</title>
      </sec>
      <sec id="sec-2-2">
        <title>2https://duc.nist.gov/data.html 3https://rb.gy/gp1gbt 4https://rb.gy/v4u2g</title>
        <sec id="sec-2-2-1">
          <title>Gold Abstrac</title>
          <p>tive Summary</p>
        </sec>
        <sec id="sec-2-2-2">
          <title>Reference</title>
        </sec>
        <sec id="sec-2-2-3">
          <title>Extractive Summary</title>
        </sec>
        <sec id="sec-2-2-4">
          <title>Lead TR STR</title>
          <p>Ever noticed how plane seats appear to be getting smaller and smaller? With increasing numbers of
people taking to the skies, some experts are questioning if having such packed out planes is putting
passengers at risk.</p>
          <p>Experts question if packed out planes are putting passengers at risk. U.S consumer advisory group says
minimum space must be stipulated.</p>
          <p>Ever noticed how plane seats appear to be getting smaller and smaller?. This week, a U.S consumer
advisory group set up by the Department of Transportation said at a public hearing that while the
government is happy to set standards for animals flying on planes, it doesn’t stipulate a minimum
amount of space for humans.</p>
          <p>Ever noticed how plane seats appear to be getting smaller and smaller? With increasing numbers of
people taking to the skies, some experts are questioning if having such packed out planes is putting
passengers at risk.</p>
          <p>They say that the shrinking space on aeroplanes is not only uncomfortable - it’s putting our health and
safety in danger. This week, a U.S consumer advisory group set up by the Department of Transportation
said at a public hearing that while the government is happy to set standards for animals flying on
planes, it doesn’t stipulate a minimum amount of space for humans.</p>
          <p>They say that the shrinking space on aeroplanes is not only uncomfortable - it’s putting our health and
safety in danger. ’It is time that the DOT and FAA take a stand for humane treatment of passengers.
to the current summary set. The subset of sentences that summarization methods, namely the Baseline (Lead),
Texwe have at this point is then considered the extractive ref- tRank (TR), and our proposed method, SentiTextRank
erence summary for the evaluation. In Table 1 we report (STR) evaluated on single-document datasets DUC-2001
an example of summaries generated with the diferent (D01) and CNN, and the multi-document datasets
DUCmethods. 2001 (MD01) and DUC-2004 (MD04). As a baseline, we</p>
          <p>Table 1 reports an excerpt from the CNN dataset (Orig- selected the leading sentences from the original
docuinal Text) and the corresponding reference summary ments based on the compression ratio. We evaluated
(Gold Abstractive Summary). Moreover, Table 1 con- the summaries using two measures: Rouge-L F1 (RL-F1)
tains the corresponding generated reference extractive and BERT F1. ROUGE (Recall Oriented Understudy for
summary (Reference Extractive Summary), the prefix Gisting Evaluation) is frequently used to assess how well
baseline (Lead), the text generated with the TextRank summarization techniques perform. Rouge-L computes
baseline (TR) and, finally, the SentiTextRank generated ROUGE for the longest sequence of n-grams [9]. BERT
summary (STR). F1 score is a metric commonly used in text classification
tasks. It measures the token-level similarity between the
Dataset Algorithm RL-F1 BERT-F1 generated summary and the reference summary,
consid</p>
          <p>Lead 0.600 0.729 ering both precision and recall [10].</p>
          <p>D01 TR 0.382 0.649 The results consistently indicate that the Lead method
STR 0.366 0.605 outperforms the other methods across the datasets,
showLead 0.711 0.794 casing its superiority in generating high-quality
sumCNN TR 0.345 0.642 maries. Specifically, Lead achieves the highest scores in
STR 0.372 0.608 Rouge-L F1 and BERT-F1 for D01, CNN, MD01, and MD04.</p>
          <p>Lead 0.802 0.851 The TR and STR methods exhibit moderate performance
MD01 STTRR 00..016631 00..550605 in specific evaluation metrics.</p>
          <p>Lead 0.511 0.683 Note that the better performance of the Lead method
MD04 TR 0.123 0.575 can be attributed to the fact that all the experiments were
STR 0.227 0.542 conducted using news datasets; indeed this result is
consistent with the results reported in the literature, where
Table 2 a baseline composed of the leading sentences frequently
The results of summarization experiments. Lead = Lead Base- outperforms extractive and abstractive models on news
line, TR = TextRank, STR = SentiTextRank. datasets [11]. However, we think that the comparison
between original TR and STR shows encouraging results.</p>
          <p>Table 2 presents the experimental results of diferent Indeed, the fact that using emotions does not degrade
the performance with regard to TextRank shows that
we can produce a summary that represents the content
as well as the emotions of the source documents. In
order to experimentally prove this intuition, we need to
formalize an emotional distance between summaries and
source documents. We plan to develop this point in the
future by both (1) using LLM and (2) considering human
evaluation.</p>
          <p>Further research is necessary to evaluate the
performance of our proposed STR method on another domain
dataset to provide a comprehensive understanding of its
efectiveness.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>4. Conclusion and Future Work</title>
      <sec id="sec-3-1">
        <title>This paper introduces the SentiTextRank algorithm,</title>
        <p>which integrates emotions into the extractive
summarization process to create more informative and emotionally
rich summaries. The experimental results are
encouraging with respect the efectiveness of SentiTextRank in
capturing factual information.</p>
        <p>The ongoing work on SentiTextRank is following
different directions.</p>
        <p>First, we want to design a new version of the
algorithm that will not be based on the classification of a
sentence in one single prevalent emotion. The idea that
we want to develop is to define one single measure that
combines both content and emotion similarities. By
using this combined measure, we can apply the original
TextRank algorithm on the entire set of sentences from
the source(s) and obtain one single ranking structure
accounting for both content and emotion.</p>
        <p>Second, we want to conduct more extensive
experiments also on datasets from diferent domains. In
particular, we are considering medical applications since the
afective component of medical information can
represent a relevant biopsychosocial feature [12].</p>
        <p>Third, we are aware that automatic metrics not always
measure a real quality of the summarized text with
respect to human judgment [13, 14]. So, we plan in future
to conduct human-based evaluation too.</p>
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