<!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>Can the strength of co-citation linkages be evaluated using context-aware citation network embeddings⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Masaki Eto</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Gakushuin Women's College</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tokyo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Japan</string-name>
          <email>P@1</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Table 1 Mean scores of</institution>
        </aff>
      </contrib-group>
      <fpage>83</fpage>
      <lpage>86</lpage>
      <abstract>
        <p>Co-citation linkages are commonly employed to measure implicit relationships between documents. However, traditional co-citation techniques equivalently treat the strengths of co-citation linkages within a single citing document, limiting technique effectiveness. This study explores whether context-aware citation network embeddings can be used to more accurately measure the strength of co-citation linkages within a single citing document. In particular, this study proposes a novel method that incorporates context-aware citation network embeddings into the co-citation approach and empirically evaluates its performance. Experimental results show that the proposed method outperforms a baseline based on traditional co-citation techniques. Thus, the proposed method can discriminate between weak and strong co-citation linkages.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;co-citation</kwd>
        <kwd>network embedding</kwd>
        <kwd>citation context 1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In scientometrics or information retrieval, co-citation linkages are commonly used to measure
implicit relationships between documents. However, traditional co-citation techniques equivalently
treat the strengths of these linkages within a single citing document, presenting a notable
limitation. Although some techniques attempt to distinguish between weak and strong co-citation
linkages using surface structures like paragraphs [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ][
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], some challenges still exist. For example, if
two similar documents are cited in analogous citation contexts but appear in separate paragraphs,
the strength of their co-citation linkage may be inaccurately assessed as weak.
      </p>
      <p>
        In recent years, techniques that utilize embeddings, such as bidirectional encoder
representations from transformers (BERTs) [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], have enabled sophisticated analyses of citation
contexts, potentially offering a solution to this problem. This study aims to investigate whether
context-aware citation network embeddings can effectively measure the strength of co-citation
linkages within a single citing document. To this end, this study proposes a novel method that
applies context-aware citation network embeddings to co-citation analysis and empirically
evaluates the performance of the proposed method.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Proposed method</title>
      <sec id="sec-2-1">
        <title>The proposed method generates citation network embeddings that are aware of the citation context</title>
        <p>
          [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. This technique fine-tunes the SciBERT model [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ] in the masked paper prediction task. In this
task, a cited document is masked (Figure 1), and the SciBERT model is trained to predict the cited
document from the citing document and the citation context. A previous study [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] used this
technique for citation recommendation, which predicts additional documents that may be suitable
as replacements for the masked document.
        </p>
        <p>Document X (citing document)
-------[A].--------- [MASK]
--------------------- masked document
[MASK].---------- Document B is original cited document
--------.---------------[C]--------------- Documents A, C and D
------------[D]. the other cited documents</p>
        <p>This study employs this technique to measure the strength of co-citation linkages within a
single citing document. The proposed method also predicts suitable documents, where the
predicted documents are limited to other documents cited in the same citing document. As shown
in Figure 2, the proposed method employs the context of the original citing document B and the
cited documents (A, C, and D) to output a list of ranked documents that may be suitable as
replacements for masked document B. This ranking also indicates the strength of the co-citation
linkage with document B; the strongest linkage is between documents B and D.</p>
        <p>Citation context in Doc. X
-----[MASK]----------(Originally Doc. B is cited)</p>
        <p>The other documents
cited by Doc. X</p>
        <p>Doc. A Doc. C Doc. D</p>
        <p>Masked paper prediction by fine-tuned SciBERT
Rank
1st Doc. D
2nd Doc. C
3ird Doc. A</p>
        <p>Strong
Weak</p>
        <p>B
B
B</p>
        <p>Co-citation linkage
D between B and D</p>
        <p>Co-citation linkage
C between B and C</p>
        <p>Co-citation linkage</p>
        <p>A between B and A</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Experimental setup</title>
      <sec id="sec-3-1">
        <title>This study conducted an experiment using the FullTextPeerRead dataset [6]. This dataset</title>
        <p>
          comprises 16,669 citation contexts, each comprising the texts preceding and following the citation
position, the ID of the cited document, the title and abstract of the cited document, and the ID of
the citing document. For each context, the texts were split into sentences using spaCy, which was
loaded along with a biomedical text processing model (the en_core_sci_scibert model) [
          <xref ref-type="bibr" rid="ref7">7</xref>
          ]. This
experiment used the two sentences preceding and following the citation position.
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>The aim of this experiment was to evaluate the effectiveness of the proposed method in terms of</title>
        <p>
          document ranking. In this evaluation, a document was considered relevant if it shared one or more
indexing terms with the original cited document. As in a previous study [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ], the names of the
machine learning tasks defined in paperswithcode (https://paperswithcode.com/sota) were used as
the indexing terms. These terms were searched for in the title and abstract of each cited document
via string matching.
        </p>
      </sec>
      <sec id="sec-3-3">
        <title>For the ranking tasks, 1,362 citation contexts were extracted from the dataset under the condition that the documents to be ranked contained at least one relevant document and one irrelevant document. The extraction process excluded tasks that could not discriminate between ranking performances.</title>
        <p>
          The parameters used to fine-tune the SciBERT model were identical to those employed in a
previous study [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. In particular, the experiment used a batch size of 16, a learning rate of 5e−5, and
        </p>
      </sec>
      <sec id="sec-3-4">
        <title>5 training epochs. The maximum length of the sub tokens preceding and following each citation</title>
        <p>position was set to 125. The sum of the token word/document, position, and token-type
embeddings was used as the input representation. To fine-tune the model, the experiment used
15,307 citation contexts obtained by excluding the 1,362 contexts used for the ranking tasks from
the 16,669 citation contexts.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Evaluation results</title>
      <sec id="sec-4-1">
        <title>The experiment evaluated the ranking performance of the proposed method using two metrics: the</title>
        <p>precision of the top-ranked document (P@1) and the average precision (AP). Moreover, a baseline
method based on traditional cocitation techniques was used for comparison. In particular, this
baseline method ranks documents randomly because traditional co-citation techniques treat the
strength of co-citation linkages within a single citing document as equivalent.</p>
        <sec id="sec-4-1-1">
          <title>Baseline</title>
        </sec>
        <sec id="sec-4-1-2">
          <title>Proposed method</title>
        </sec>
        <sec id="sec-4-1-3">
          <title>Mean P@1 0.466 0.570</title>
        </sec>
        <sec id="sec-4-1-4">
          <title>Mean AP 0.629 0.704</title>
        </sec>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusion</title>
      <sec id="sec-5-1">
        <title>This study investigated whether context-aware citation network embeddings can effectively measure the strength of co-citation linkages within a single citing document. The experimental results demonstrated that the proposed method successfully differentiates between weak and strong co-citation linkages.</title>
      </sec>
      <sec id="sec-5-2">
        <title>A potential direction for future research is to apply the proposed method to scientometrics. By</title>
        <p>accurately measuring co-citation strength using even a single citing document, the proposed
method can enable the creation of co-citation maps with fewer citations. This applicability could be
particularly valuable for mapping new knowledge domains where the number of citations is
insufficient.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgements</title>
      <sec id="sec-6-1">
        <title>This work was supported by JSPS KAKENHI Grant Number 23K11776.</title>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>Declaration on Generative AI</title>
      <sec id="sec-7-1">
        <title>The author has not employed any Generative AI tools.</title>
      </sec>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>Bela</given-names>
            <surname>Gipp</surname>
          </string-name>
          and
          <string-name>
            <given-names>Joeran</given-names>
            <surname>Beel</surname>
          </string-name>
          .
          <year>2009</year>
          .
          <article-title>Citation proximity analysis (CPA) - a new approach for identifying related work based on co-citation analysis</article-title>
          .
          <source>Proceedings of the 12th International Conference on Scientometrics and Informetrics (vol. 2</source>
          , pp.
          <fpage>571</fpage>
          -
          <lpage>575</lpage>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>Masaki</given-names>
            <surname>Eto</surname>
          </string-name>
          .
          <year>2013</year>
          .
          <article-title>Evaluations of context-based co-citation searching</article-title>
          .
          <source>Scientometrics</source>
          ,
          <volume>94</volume>
          (
          <issue>2</issue>
          ),
          <fpage>651</fpage>
          -
          <lpage>673</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>Jacob</given-names>
            <surname>Devlin</surname>
          </string-name>
          ,
          <string-name>
            <surname>Ming-Wei</surname>
            <given-names>Chang</given-names>
          </string-name>
          ,
          <string-name>
            <given-names>Kenton</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <string-name>
            <given-names>and Kristina</given-names>
            <surname>Toutanova</surname>
          </string-name>
          .
          <year>2019</year>
          .
          <article-title>BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding</article-title>
          .
          <source>In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies</source>
          , Volume
          <volume>1</volume>
          (Long and Short Papers), pages
          <fpage>4171</fpage>
          -
          <lpage>4186</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>Masaya</given-names>
            <surname>Ohagi</surname>
          </string-name>
          and
          <string-name>
            <given-names>Akiko</given-names>
            <surname>Aizawa</surname>
          </string-name>
          .
          <year>2022</year>
          .
          <article-title>Pre-trained Transformer-Based Citation ContextAware Citation Network Embeddings</article-title>
          .
          <source>In The ACM/IEEE Joint Conference on Digital Libraries in 2022 (JCDL '22)</source>
          , June 20-24,
          <year>2022</year>
          , Cologne, Germany.
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>Iz</given-names>
            <surname>Beltagy</surname>
          </string-name>
          , Kyle Lo, and
          <string-name>
            <given-names>Arman</given-names>
            <surname>Cohan</surname>
          </string-name>
          .
          <year>2019</year>
          .
          <article-title>SciBERT: A Pretrained Language Model for Scientific Text</article-title>
          .
          <source>In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)</source>
          , pages
          <fpage>3615</fpage>
          -
          <lpage>3620</lpage>
          ,
          <string-name>
            <surname>Hong</surname>
            <given-names>Kong</given-names>
          </string-name>
          , China. Association for Computational Linguistics.
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <surname>Jeong</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Jang</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Park</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Choi</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          <year>2020</year>
          .
          <article-title>A context-aware citation recommendation model with BERT and graph convolutional networks</article-title>
          .
          <source>Scientometrics</source>
          ,
          <volume>124</volume>
          ,
          <fpage>1907</fpage>
          -
          <lpage>1922</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>Mark</given-names>
            <surname>Neumann</surname>
          </string-name>
          , Daniel King, Iz Beltagy, and
          <string-name>
            <given-names>Waleed</given-names>
            <surname>Ammar</surname>
          </string-name>
          .
          <year>2019</year>
          .
          <article-title>ScispaCy: Fast and Robust Models for Biomedical Natural Language</article-title>
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>