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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Identifying Fake News Spreaders in Social Media</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>IIIT</institution>
          ,
          <addr-line>Hyderabad</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Nikhil Pinnaparaju</institution>
          ,
          <addr-line>Vijaysaradhi Indurthi, and Vasudeva Varma</addr-line>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2020</year>
      </pub-date>
      <abstract>
        <p>With the rise of social networking platforms, everyone now has free access to information from around the work. Anyone from anywhere can now share context with the entire world. This allows for more connectivity around the world and more transparency. However, this also allows for the spread of misinformation and fake news often resulting in undesired and extremely impactful political, economic, social, psychological and criminal consequences. Identifying the fake news spreaders is as important as identifying the fake news itself. We put forward a method to utilize content analysis and more user modelling to capture who is more likely to share fake news. We use TF-IDF as our text transformation method coupled with algorithms simple classification algorithm Logistic Regression and achieve an accuracy of 71.5% and 70% in identifying fake news spreaders in both the English as well as Spanish test set respectively.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Recently we have seen the rise of many social platforms like Facebook, Twitter, Reddit,
Snapchat and so many more. These platforms serve as great ways for any and everyone
to share content, information and so much more. With this power, comes with bad actors
that misuse it to spread disinformation, fake news and rumors. It is important that we
identify these bad actors and are able to contain the impact they make on the platform.
The task proposed by Rangel et al. [10] allows us to detect these bad actors in both
English and Spanish.</p>
      <p>
        For this task we experiment with various machine learning techniques and compare
their performance on the task. We use models like Logistic Regression[7], Random
Forest[
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], Support Vector Machines[
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] and XGBoost[
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] because of their smaller size in
terms of the number of parameters and show they perform well. Another reason for
utilizing simpler model architectures is due to the amount of data we have accessible and
how data-hungry deep neural architectures can get. All submissions are made through
the Tira system[9].
      </p>
    </sec>
    <sec id="sec-2">
      <title>Background</title>
      <p>– Content Based
– User Based
Traditional methods of fake news detection rely primarily on two techniques either</p>
      <p>
        In content based techniques, models are used to try to capture whether a piece of
text is fake or not.[
        <xref ref-type="bibr" rid="ref3">3</xref>
        ][8] Most work tries to detect fake news based on linguistic features
from the text or otherwise capture the style of the text.
      </p>
      <p>The only method direction of work is user based detection, in which they try to
assign a credibility to users and detect based on that.[6]</p>
      <p>The differentiating aspect of this work is that we are trying to identify fake news
spreaders based on the content they share and not using features like follower count,
tweet count, etc.
3</p>
    </sec>
    <sec id="sec-3">
      <title>Identifying Fake News Spreaders</title>
      <p>In this task of identifying fake news spreaders, 300 author’s tweets have been provided
for English and Spanish respectively. For each author 100 tweets are available. The
task is to build computational models to identify whether a given author is a fake news
spreader or not. The official metric of evaluation is the combined accuracy of both the
languages.
4</p>
    </sec>
    <sec id="sec-4">
      <title>System overview</title>
      <p>We chose to participate in both the language tracks, English and Spanish. We formulate
the problem of identifying fake news spreaders by treating it as a document
classification problem. We concatenate all the tweets of a given author and consider it as a
single big document corresponding to the author. With this approach, each author is
represented by the collection of all his tweets concatenated together.</p>
      <p>Empirical observations showed that it is the terms of the tweets which are
significant in identifying if the author is a spreader of fake news or other wise. Since the
presence of specific terms is key to this task, we use a very simple transformation
TF-IDF algorithm to transform the training data into numeric vector representations for
training as TF-IDF is sequence invariant i.e the sequence of the terms do not matter.
We could have used some recent embedding models like Word2vec or GloVe but as
the document size is large and consists of around 100 tweets, the average embedding
technique dilutes the word embeddings and the resulting transformation would not hold
the semantic representation of all the tweets of that author. Hence we did not delve in
word embeddings.</p>
      <p>The following pre-processing is done before the training data is transformed with
TF-IDF. For each tweet, we remove all the occurrences of retweets (’RT’), mentions of
user (’#user#’), mentions of hashtags (’#hashtag#’) and mentions of urls (’#url#’). In
addition all the text is lowercased.</p>
      <p>The transformed representations are then fed into a simple classification algorithm
like Logistic Regression. The advantage with the logistic regression is that the resulting
model can be interpreted.
5</p>
    </sec>
    <sec id="sec-5">
      <title>Experimental setup</title>
      <p>In this shared task, the training dataset consisted of tweets tweeted by 300 authors. For
each author, 100 tweets tweeted by him are available for training. In our experimental
setup, we used 5-fold cross validation. For each fold, we trained on the 80% of the
authors and evaluated on the remaining 20% of the authors. We keep the experimental
same for both the languages.</p>
      <p>
        We use sklearn [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] for all our experiments. We experiment with four classification
algorithms - Logistic Regression, Random Forest, SVM and XGBoost. We also use
the default hyper parameters provided by the sklearn as we didn’t want to overfit to
the training dataset. First, we show the 5-fold cross validation performance of these
algorithms. Then, we pick the best performing algorithm and train the model again, this
time utilising the full training data available and use this model to make predictions on
the task’s test set which is not publicly available.
6
      </p>
    </sec>
    <sec id="sec-6">
      <title>Cross Validation Results</title>
      <p>To conclude, we describe the methods we applied for the task. We show the processing
steps involved along with the results achieved by each of the models. Future work would
be along attempting to apply and use deep learning and state of the art methods and see
their performance on this task.
6. Gupta, M., Zhao, P., Han, J.: Evaluating event credibility on twitter. In: Proceedings of the
2012 SIAM International Conference on Data Mining. pp. 153–164. SIAM (2012)
7. Pearl, R., Reed, L.J.: On the rate of growth of the population of the united states since 1790
and its mathematical representation. Proceedings of the National Academy of Sciences of
the United States of America 6(6), 275 (1920)
8. Popat, K., Mukherjee, S., Strötgen, J., Weikum, G.: Credibility assessment of textual claims
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and Knowledge Management. pp. 2173–2178. ACM (2016)
9. Potthast, M., Gollub, T., Wiegmann, M., Stein, B.: TIRA Integrated Research Architecture.</p>
      <p>In: Ferro, N., Peters, C. (eds.) Information Retrieval Evaluation in a Changing World.</p>
      <p>Springer (Sep 2019)
10. Rangel, F., Giachanou, A., Ghanem, B., Rosso, P.: Overview of the 8th Author Profiling
Task at PAN 2020: Profiling Fake News Spreaders on Twitter. In: Cappellato, L., Eickhoff,
C., Ferro, N., Névéol, A. (eds.) CLEF 2020 Labs and Workshops, Notebook Papers.
CEUR-WS.org (Sep 2020)</p>
    </sec>
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