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    <article-meta>
      <title-group>
        <article-title>Big Data Analytics for Opinion Mining and Patterns Detection of the Tunisian Election</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Zeineb Dhouioui Hanen Bouali</string-name>
          <email>zeineb.dhouioui@hotmail.fhranene.bouali</email>
          <email>zeineb.dhouioui@hotmail.fhranene.bouali@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jalel Akaichi</string-name>
          <email>j.akaichi@gmail.com</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Bestmod Laboratory Bestmod Laboratory, ISG Tunis ISG Tunis, University of Tunis University of Tunis</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Bestmod Laboratory, ISG Tunis, University of Tunis</institution>
        </aff>
      </contrib-group>
      <fpage>157</fpage>
      <lpage>164</lpage>
      <abstract>
        <p>Big Data refers to an enormous volume of structured and unstructured data that cannot be handled with traditional databases. The emergence of big data is due to the huge quantities of information. Currently, researchers tend to study big data particularly data produced from social networks. Nowadays, these latest become a vital and crucial tool in tracking and extracting public opinion for developed countries o↵ ering benefits to the democratic process of election. In this paper, we aim to identify the political preferences and tendency of the Tunisian population using classification and opinion mining techniques. To prove the usefulness of the proposed method, we analyze electoral data sets in Tunisia obtained from the o cial sites of independent higher instance for election. This analysis demonstrates close correspondence between election results and extracted opinion.</p>
      </abstract>
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    <sec id="sec-1">
      <title>-</title>
      <p>
        Big data is an extensively used term in
tremendous data miscellany. Thus, this huge amount of
data makes hard and sometimes impossible the
analysis in a comfortable way using traditional
data processing techniques
        <xref ref-type="bibr" rid="ref12 ref14 ref2 ref3">(Anjaria and Guddeti,
2014)</xref>
        . The dares includes pattern recognition,
analysis, prediction ... Given the benefits of big
data, they a↵ ord a chance to understand collected
data in order to predict data patterns. With
millions of people using social networks to express
their opinions, a tremendous volume of data is
generated. Unfortunately, elections data that was
published by the ISIE present only a summary of
the vote counts. Detailed data is not accessible.
Combining social networks data and ISIE data,
voter behavior can be defined.
        <xref ref-type="bibr" rid="ref15">(Sudhahar et al.,
2015)</xref>
        With the evolution of the web 2.0 and the large
number of users, big data analysis becomes very
useful in pattern detection. Particularly, we
handle in this paper Tunisian Voters in legislative
and presidential election. Indeed, despite the
mutual relation between socio-economic
characteristics and voters in Tunisian elections, for the
best of our knowledge, no researchers treat this
task. Moreover, Elections in countries on path
to democracy are considered as a source of
enormous quantity of data.
      </p>
      <p>The exponential rise of social networks
popularity influences real-world politics. These
platforms have been exploited in Arab revolution as
a mobilization tool and showing social
movements. Moreover, social networks are used to
study voters preferences in order to forecast
electoral results. We cant ignore the role of social
networks especially Facebook in our election,
using opinion mining we can analyze and
predict the voting intention of Facebook users in
Tunisia for the 2014 presidential election. The
huge amounts of public opinion data need
accurate tools to extract useful information.
In this study, we exploit stables and some
statistical o cial data from ISIE in order to identify
possible correlations between socio-economic
features of voters and elections results.
Furthermore, to well draw voting behavior, we study
psychological sociological and economic
variables. Thus we have discovered high correlation.
The exploited data consists of the results of the
Tunisian election of 2014 and 2011, also as we
said previously some socio-economic variables
and some data from social networks especially
Facebook and Twitter. In fact, we treat Facebook
activity data during months preceded the
legislative and presidential elections. An important part
of our study is to determine positive and negative
opinions. These opinions can then be interpreted
to define the political position of voters.
Persons who share several common
characteristics present a tendency to have common voting
behavior. We are interested in establishing
voting behavior according to voter0s profile.
The remainder of this paper is as follows: in
part 2, we discuss existing works handling
Socioeconomic variables a↵ ecting elections results
and voter0s sentiment analysis. In part 3, we
present data and methodologies use in this
paper in order to present opinion mining patterns
of voters in the Tunisian election in part 4.
Finally, an overview of our work and opportunities
that has been opened up are provided in part 5.</p>
      <p>Related Works
Before presenting the use case of this paper, we
flew over existing works handling opinion
mining voters patterns. Two sides were manages:
• Patterns a↵ ected by socio-economic
variables
• Voter0s sentiment analysis
2.1</p>
      <p>
        Socio-Economic Variables
The paper develops in
        <xref ref-type="bibr" rid="ref11">(Kreuzer and Pettai,
2003)</xref>
        an analytical framework, which
incorporate politician driven inter-party mobility and
voter induced electoral changes. The proposed
framework was applied in Estonia, Latvia and
Lithuania. Authors develop di↵ erent strategies
and patterns which are:
• Organizational A liation Strategies:
– Staying Put
– Party Switching
– Fusion
– Fission
– Starting Up
• Electoral A liation Strategies:
– The frequency of voters a liation
changes
– Voters preferences among for di↵ erent
party origin
• Patterns of Party Systems Transformation:
– Alignment patterns
– Re-alignment patterns
– De-alignment patterns
• Organizational A liation Patterns of
Politicians
• Electoral A liation Patterns of Voters:
2.2
– Parties having won at least one seat
– Parties emerging from break away
legislative
– Parties whose successor or predecessor
(through fusion or fission) won at least
one seat
Other patterns were detected in
        <xref ref-type="bibr" rid="ref1">(Akarca and
Tansel, 2007)</xref>
        which study the voters0 behavior
in Turkey. Authors found that Turkish voters take
economic performances into account and voters
exhibit a tendency to vote against parties holding
power. In addition to that, party preferences of
Turkish depend on their socio-economic
characteristics. Moreover, Voters distinguish between
major and minor parties and hold party
accountable for economic growth. The growth rate more
than a year before an election does not a↵ ect its
outcome. Later, a comparative analysis of voter
turnout in regional elections is made in
        <xref ref-type="bibr" rid="ref9">(Henderson and McEwen, 2010)</xref>
        . This paper conducts a
cross sectional examination of voter participation
in regional elections in nine states between 2003
and 2006. Authors found that variations in the
strength of political autonomy and the strength
of attachment to the region among the electorate
have a strong and positive impact on the level
of turnout in regional election. The hypothesis
of voter turnout in regional election is higher in
regions with a high degree of regional
distinctiveness was proved. Other works were done to
see the impact of weather on the voter turnout in
        <xref ref-type="bibr" rid="ref14">(Persson et al., 2014)</xref>
        .The case of Swedish
election system was studied, authors cannot find a
robust and statistically significant negative e↵ ect
of Election Day rain turnout, unlike in the US
one inch of rain reduces turnout with about one
percent.
      </p>
      <p>
        We should firstly define sentiment analysis called
also opinion mining, it is considered as a new
text analysis
        <xref ref-type="bibr" rid="ref6">(Choy et al., 2011)</xref>
        . In fact,
sentiment analysis is a technique serving to
analyze people0s opinions, sentiments, appraisals,
and emotions. There have been several works
in this area, in
        <xref ref-type="bibr" rid="ref6">(Choy et al., 2011)</xref>
        authors
discussed how sentiment analysis can predict
presidential election results in Singapore according
to the conversion of Twitter data. In
        <xref ref-type="bibr" rid="ref5">(Ceron et
al., 2015)</xref>
        , the presented methodology consists
on applying supervised method to analyze the
voting intention of Twitter users in the United
States during the 2012 presidential election and
for the two round of the centre left2012 primaries
in Italy. Authors
        <xref ref-type="bibr" rid="ref10">(Jungherr et al., 2012)</xref>
        check out
whether Twitter a↵ ects the information exchange
about political a↵ air. They also present an
evaluation about Twitter messages which may
reflect political sentiment. Moreover, they analyze
Twitter activity in order to predict parties
popularity. In
        <xref ref-type="bibr" rid="ref7">(Conover et al., 2011)</xref>
        , the main idea
was to apply latent semantic analysis to tweets,
and thus they discover hidden structure. Later,
Lei et al in [10] propose a model able to predict
the public opinions about republican presidential
elections. Finally, in
        <xref ref-type="bibr" rid="ref4">(Ceron et al., 2014)</xref>
        authors
assert that sentiment analysis gives accurate
predictions and can become useful in polls.
Moreover,authors in
        <xref ref-type="bibr" rid="ref13">(Mohammad et al., 2014)</xref>
        automatically annotate a set of 2012 US
presidential election tweets for a number of attributes
pertaining to sentiment, emotion, purpose, and
style by crowd sourcing. They show through an
analysis how public sentiment is shaped, tracking
public sentiment and polarization with respect to
candidates and issues, understanding the impact
of tweets from various entities. Other research
such as
        <xref ref-type="bibr" rid="ref8">(Dridi, 2015)</xref>
        present a system for
finding, from Twitter data, events that raised the
interest of users within a given time period and the
important dates for each event. In order to select
the set of events, they used three main criteria:
frequency, variation and Tf-Idf.
3
      </p>
      <p>
        Data and Methodology
To reach our objective, we have chosen the
results of the 2014 parliamentary and presidential
elections in Tunisia. The election results were
fairly contested and were not surrounded by any
extraordinary events. The sources of our data are
the web site of the Independent Higher Instance
for Election (ISIE) 2014 and the National
Institute of Statistic (INS). The two references report
the data from 24 governors and 264 delegations
for the legislative, the first and second round in
presidential election. We collected also Twitter
and Facebook information from the start of the
legislative election on October 2011 and the
electoral campaign from August 2014 to the end of
second round of presidential election. Political
tweets and Facebook comments includes those
coming from followers and candidates. To
analyze data collected from ISIE and INS, we
apply WEKA algorithms. A study in
        <xref ref-type="bibr" rid="ref12 ref14 ref2 ref3">(Bouali and
Akaichi, 2014)</xref>
        has been done and proves the
efficiency and e cacy of Support Vector Machine.
The first step is to load an excel file to Weka.
Second, we select SVM as technique. Then, in
the training set, we choose the method of cross
validation and we select classification0s attribute.
Later on, to extract the sentiment of the collected
data, we use opinionFinder. We proceed first for
the data preprocessing. Second, we identify
sentiment expression in the text document. Then, we
detect two sets of expressions: those written in
formal languages (English, Arabic and French)
and those in informal languages. Thus, the first
set is handled using SentiStrength tool and the
second one manually. Emoticons significance is
also detected using SentiStrength. In this section
we propose a general method; this framework is
divided into 3 steps:
• Step 1 : Data Collection : status are
collected according to the most frequently used
keywords. Status containing insults are
removed, and status written in di↵ erent
languages are handled manually.
      </p>
      <p>People discus and express their opinion by
commenting, posting or sharing status (or
tweets). We are interested only to status,
tweets and comments containing keywords
related to election, parties and candidates
manually found. People publications may
contains emoticons and informal language,
thus we should analyze those manually.
After finding appropriate status or comments
referring to our subject, the collected data
consists of 274 status and 586 comments.
• Step2 : Status Classification</p>
      <p>Counting the number of positive, negative
and neutral messages. Actually, using
opinionFinder tool we are able to extract
automatically subjective sentences and
sentiment expressions. Based on SentiStrength
which estimates the strength of positive and
negative sentiment in texts and emoticons
in various languages, we classify words into
categories.</p>
      <p>To design the voter profile, our system is
based on identifying his sentiment.
Consequently, we can conclude if a given voter
is with or against party or candidate.
Additionally, we can interpret his preferences
according to his opinion.
The aim of this work is to determine whether
social networks data, and the data gathered from
the ISIE o cial site can predict election
results. The figure below illustrates the proposed
methodology 1:</p>
      <p>Empirical Results</p>
      <p>Voter Behavior
The objective of this paper is to extract relevant
and interesting knowledge from big amount of
data using supervised learning techniques. when
applying our chosen methodology, our important
finding is that voters distinguish between major
and minor parties in a governing coalition and
hold only the major incumbent party accountable
for economic growth.</p>
      <p>There is a tendency for parties to lose or win
portion of their votes between first and second round
due to political mergers which eventually happen
in the second round. This refers to voter turnout
patterns which are:
• Staying put: a voter remains a liated with
his her party in legislative and both rounds
of presidential election.
• Party Switching: di↵ erent from fusion
(party0s voters re-a liates in the form of a
merger with another party).
• Starting up: una liated voters change their
opinion to be a liated to another party. We
have found that Islamist party represented
by Mohamed Moncef Marzouki (MM
receives their votes from people living in
areas su↵ ering from lack of economic growth
such as Sidi Bouzid, Kebili... NIDAA
TOUNESS represented by Beji Caied
Sebssi (BCE) received their votes from those
living in regions experiencing good
economic conditions and economic growth like
Tunis, Nabeul 2.</p>
      <p>The recent election shows a decrease in
NAHDHA (Political Party) partisans instead
of an increase in NIDAA TOUNESS(Political
Party). This is due to several reasons:
• A tendency to vote against the parties
holding power: voters who votes BCE to
decrease the power to MMM.
• Government0s economic performance
• Decrease of Quality of life
• Increase of poverty rates.</p>
      <p>We observed that citizens of a minor
socioeconomic status don0t exhibit political e cacy
and commonly ”participate less in the voting
process”. In contrast, citizens with important
socioeconomic status participate and sponsor the
political process. Thus, voter0s income and
occupation are crucial in vote0s process. We mention
that high education level and low level of
illiteracy are behind significant civic activity 3. We
found also that woman voted more to BCE.
4.2</p>
    </sec>
    <sec id="sec-2">
      <title>Voter Sentiment</title>
      <p>Tunisian presidential election 2014 in the
second round was limited between two main
candidates where the concurrence was severe and
intense. Actually, most sentiment and opinion have
been predicted and discovered according to
online discussions, status and comments.
Collecting and analyzing sentiment is essential for
electoral campaigns. Indeed, the enormous quantity
of data related to public sentiment and opinion
is considered as big data which played a crucial
role for Obama campaign.</p>
      <p>
        With the accessibility of social networking sites,
internet users can easily express their opinions
about various topics. Thus, we can exploit and
mine the shared opinions. In this work, we
collect data from Facebook, we focus on the content
of status containing a reference to political party
or also politician
        <xref ref-type="bibr" rid="ref12">(Mehndiratta et al., 2014)</xref>
        .
In the following table, we present an example of
positive, negative and neutral tweets. The
fig
      </p>
    </sec>
    <sec id="sec-3">
      <title>Opinion</title>
    </sec>
    <sec id="sec-4">
      <title>Nature</title>
      <p>Positive</p>
      <sec id="sec-4-1">
        <title>Negative</title>
      </sec>
      <sec id="sec-4-2">
        <title>Neutral</title>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Tweet Example</title>
      <sec id="sec-5-1">
        <title>Financial Times: L’lection de</title>
        <p>Caid Sebssi est une chance pour
la Tunisie
Des tunisiens craignent un retour
en arrire aprs lection de BCE!
BCE: Rencontre avec les
prsident des clubs sportifs
ures below (figure 4 and 5) provide a curve that
mentions the evolution of the number of tweets
between August 15 and September 14, 2014; we
recorded 2,004 tweets containing the hashtag
TnElec. This hashtag is sometimes used more than
150 times a day for the last few weeks and also
an overview about the number of Facebook users
that like the candidates o cial pages. The x
axis represent the number of negative and
positive statues written for both presidential
candidates The number of negative status for MMM
is larger comparing to BCE according to the
collected data (figure 6) which reflects the reality i.e.
ers is a↵ ected by economic, demographic and
socio-economic characteristics.</p>
        <p>We are aware
that some interpretations require additional data.
Interpretations presented in this work can serve
as hypotheses in next elections. In bulk, despite
the limits of social networks analysis, we can
assert that our results are encouraging.</p>
        <p>De´tection</p>
      </sec>
    </sec>
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