Sentiment Analysis of Web Trends for the Antisocial Behaviour
Detection
Kristína Machová and Ján Birka
Department of Cybernetics and Artificial Intelligence, Technical University of Košice, Letná 9, Košice, Slovakia
Keywords: Sentiment Analysis, Web Trends, Antisocial Behaviour, Online Discussion, Lexicon Approach.
Abstract: The paper presents an approach to extraction of current web trends for research into automated recognition of
antisocial behaviour in online discussions. Antisocial behaviour is a drawback of online discussions as
compared to their advantages such as wisdom of crowds and collective intelligence. The first step to
recognition of antisocial behaviour is the identification of web trends connected with it. These are studied in
dynamic conditions using sentiment analysis as a webometric. A new sentiment analysis method based on a
lexicon was developed. Two modifications of the lexicon sentiment analysis method were designed and tested
involving NLP (natural language processing) and an original technique for negations and intensifications
processing. The most effective sentiment classification method was used for the extraction of web trends.
Extracted web trends were analysed in a dynamic way and findings of this analysis were compared to known
historical events.
1 INTRODUCTION
Social web platforms enable web users to share their
knowledge or ideas and express their opinions and
attitudes to various themes. Online media are an
inevitable part of modern life. They have a lot of
positive, but unfortunately, also many negative
effects on our lives. Examples of positive use of
social media are: social connectivity, education,
getting help or up-to-date information, helping to
prevent crime, building communities, etc. However,
other positive influences of the online space are
starting to attract users’ attention, namely wisdom of
crowds and collective intelligence. We can say that so
called “discourse content” (created in online
discussions) represents an instantiation of wisdom of
crowds in a rough” form of data suitable for
extraction of useful knowledge from the summarized
opinions on an important event and monitoring of
current web trends.
We have decided to use sentiment analysis for
extraction of summarized opinions and consequently
for capturing of current web trends. We have also
used sentiment analysis for extraction of information
about changes of crowd opinions throughout time. So,
our aim is a dynamic analysis of web trends. Our
sentiment analysis approach is based on a lexicon. To
improve results, we used a technique of natural
language processing for recognition of word classes
(parts of speech) and for the same purpose we have
experimented with various approaches to processing
negation and intensification.
Examples of the negative impact of social media
on our modern society are various forms of antisocial
behaviour like trolling, fake news, hoaxes, hacking,
rumours, social spamming, hate speech etc. (Ahmad,
2010). Because of the existence of antisocial content
in online discussions, some forms of regulation of
online media posting should be introduced. Our
research is oriented on new methods for the detection
of antisocial behaviour in online media. A component
part of this research is capturing current web trends,
because these web trends are probably influenced by
antisocial posts.
2 ASPECTS OF ONLINE
DISCUSSIONS
Nowadays, the Web offers a wide spectrum of
applications, which enable us to share knowledge and
experiences of a whole community of users and in this
way to create collective intelligence and wisdom of
crowds. They are highly successful and popular
within information technologies. But they also have
450
Machová, K. and Birka, J.
Sentiment Analysis of Web Trends for the Antisocial Behaviour Detection.
DOI: 10.5220/0008349104500457
In Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management (IC3K 2019), pages 450-457
ISBN: 978-989-758-382-7
Copyright
c
2019 by SCITEPRESS Science and Technology Publications, Lda. All rights reser ved
drawbacks namely connected with security problems
and the protection of web user privacy.
2.1 Collective Intelligence
Collective intelligence is the shared intelligence of a
whole group. It arises in competition or cooperation
of many people during the process of searching for a
solution or consensus in complex problems. We
assume that no individual knows everything but every
individual knows something and after a suitable
aggregation of knowledge we can obtain a form of
extensive collective intelligence (Malone, 2006).
It is clear, that collective intelligence existed
before the existence of information technologies, for
example in communities such as families, nations,
armies, etc. Typical examples of systems based on
collective intelligence are Wikipedia, Google
products, web discussions and forums, blogs, etc.
Using these platforms, human communities manage
to act with much higher intelligence as before (Lévy,
1997).
The same principles, which enable collective
intelligence, can enable collective stupidity in the
case when people blindly believe in the opinions of
some users and follow their antisocial behaviour.
2.2 Wisdom of Crowds
According to (Surowiecki, 2004) wisdom of crowds
represents a process of aggregation of anonymous
data to find a wisdom, which results from an opinion
estimation of a great number of people without any
mutual influence among them. Four basic principles
of wisdom of crowds are the following: diversity of
opinions, independence of evaluations of individuals,
decentralization (nobody will dictate his/her own
opinion) and aggregation into a collective decision. In
real life, it is not possible to ensure the principle of
independence of evaluations of community members.
The mutual influence of members of community can
leads to group thinking and tolerance of antisocial
behaviour.
2.3 Antisocial Behaviour in Online
Communities
Antisocial behaviour is connected with
disinformative content and may be of a dual nature.
First, it can represent information that will affect and
manipulate its recipients (fake news, hoax). Second,
it is misinformation, which is caused by
misunderstanding without manipulation (Kumar,
2016). The first is based on disseminating
propaganda, which tries to make reality relative by
generating arguments that distort the truth.
Sometimes this truth distortion could be generated
automatically using algorithms based on similarity
measures (Wang, 2013).
There are various disinformation techniques.
These techniques are discussed in (Řimnáč, 2018),
which presents a probability approach to the detection
of relativized statements.
Opinion sharing by product reviews is a part of
online purchasing. This opinion sharing is often
manipulated by fake reviews. The paper (Dematis,
2018) presents an approach which integrates content
and usage information in fake reviews detection. The
usage information is based on reviewers’ behaviour
trails. In this way, a reviewer’s reputation is formed.
3 USED METHODS
3.1 Text Mining
The extraction of knowledge from texts is a complex
problem. Its complexity stems from the fact, that texts
of the discourse content are unstructured and
uncertain. From such texts a new piece of knowledge
should be extracted. The new knowledge has to be
unknown until now, potentially useful, and valid in
the statistical meaning. There are a great number of
methods for text mining, for example statistic
methods, methods of supervised machine learning,
cluster techniques and also techniques of natural
language processing (Jurafsky, 2017).
3.2 Natural Language Processing
Natural language processing (NLP) is, together with
expert systems, one of the most advanced
applications of artificial intelligence. It can be applied
on a written as well as a verbal form of language. Our
work focuses on the written form to analyse
expressed opinions.
The techniques of natural language processing
represent a different approach to the techniques of
mining knowledge from texts. According to (Kao,
2005) the differences are the following:
The techniques of NLP are oriented on a
language. A text is analysed using information
about the formal grammar and dictionaries.
The mining of knowledge from texts uses
techniques of information retrieval, statistics and
machine learning methods. The goal of it is not
to understand the meaning of a text but to extract
Sentiment Analysis of Web Trends for the Antisocial Behaviour Detection
451
important patterns from great number of
documents.
Nowadays, the utilization of NLP in computer
systems grows in many domains. In this work, NLP is
used to increase the effectiveness of our method for
sentiment analysis.
3.3 Sentiment Analysis
Today, there is a growing interest in sentiment analysis
(SA), not only because it has a wide and perspective
potential in real applications but also because it can
solve more drawbacks of NLP. SA is beneficial for
marketing, research, artificial intelligence, computer
linguistics and also for social psychology.
We consider sentiment analysis to be the most
important webometric. Other webometrics like social
networks analysis (SNA) and mention analysis (MA)
are not used in this work, because SNA works with
graphs of communication instead of with texts of posts
and MA is too simplistic. Webometrics analysis is
quite a new research discipline. It uses statistical
methods for research in the area of World Wide Web
(Thelwall, 2005).
During SA, it is important to take into account
information about the kind of users whom SA targets.
Individual users and societies could have a slightly
different view on the text data. For example, the
sentence “Prices of mobiles are decreasing lately.” has
a negative meaning for companies specializing on
mobiles marketing. But the same sentence has a
positive meaning for users planning to buy a new
mobile. SA can be helpful for a common user because
it can evaluate a great amount of information, reviews
and opinions on a product in an automatic way.
The methods of SA can be divided into two main
groups: lexicon approaches and machine learning
approaches. More about sentiment analysis methods
can be found in (Machova, 2018).
The lexicon based sentiment analysis hypothesizes,
that sentiment estimation is a function of an algorithm,
data sample and external knowledge, for example in
the form of a lexicon. A lexicon contains words
together with weights for positive or negative
evaluations of each word. Such a lexicon can be
created manually, but there are also some semi-
automatic approaches to generation of it.
The algorithm of SA searches for words from the
lexicon in the analysed text. If a given word is
presented in the text, the value of its weight (negative
or positive) is extracted from the lexicon. If more
words from the lexicon are presented in the text, all
weights of these words are inputs to a function for
computing a result value of sentiment for the whole
text.
4 WEB TRENDS ANALYSIS
A concept trend is defined as a development direction
or a tendency to change something interesting for
people over time. Trends can appear in fashion or
economics but also in technologies, particularly in web
technologies. Our goal is to study some web trends
over time and analyse its development. We say that
some product or event can be considered a trend, when
many comments and posts about it can be found in
online discussions. We were interested in the nature
and polarity of these opinions and their change in time
and so we have selected sentiment analysis as the
method for web trend analysis, because sentiment
analysis naturally involves an opinion analysis. The
process of web trends analysis consisted of the
following steps.
Selection of a web discussion
Extraction of text data from the web discussion
Text pre-processing
Lexicon building
Implementing the lexicon approach to SA
Testing the lexicon approach to SA
Improvement of the lexicon approach to SA
involving possibilities of NLP
Testing the improved approach
Experiments with various methods of negation
and intensification processing
Selection of the best way of negation and
intensification processing
The second improvement of the lexicon approach
with NLP involving the selected methods for
negation and intensification processing
Testing of the second improvement
Results analysis
Within our lexicon approach to sentiment analysis
(DASA), a new lexicon was generated. The lexicon has
to contain a value of opinion polarity for each word in
the lexicon. The values of word polarity can be
generated automatically (Mikula, 2017) or the lexicon
can be derived from a lexical resource (Baccianella,
2010).
Table 1: Illustration of the lexicon derived from
SentiWordNet 3.0.
Word
Positive weight
Negative weight
conceptual
0,375
0,25
easy
0,25
0,625
unacceptable
0,125
0,375
Too-bad
0,222
0,778
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Our lexicon for DASA was derived from
SentiWord Net 3.0. The lexicon contains sets of
synonyms and their values of opinion polarity. The
total number of words included is 117659. It also
needed to be cleaned of needless words and
information using Pars.py. Table 1 illustrates the form
of the final derived lexicon.
4.1 Experiments with DASA
The DASA algorithm searches for words from the
analysed text which are presented in the derived
lexicon. In the case of a match, the value of its weight
(negative or positive) is extracted from the lexicon
and added to a sum of opinion polarity values. If the
resulting sum after processing all words from the text
is positive (negative) the opinion polarity of the
whole text is positive (negative).
At first, experiments with the basic DASA method
were performed. The results are presented in Table 2.
Table 2: Results of tests of DASA approach in known
measures Precision, Recall, F1-measure and Accuracy.
Opinion
Precision
Recall
F1
Positive
0,554
0,593
0,573
Negative
0,562
0,523
0,542
Average
0,558
0,558
0,558
All experiments with DASA and other
modifications of it (DASA Involving NLP and a new
method of negation and intensification processing)
were performed on Movie Reviews data (csfd.cz).
The data obtained texts of reviews on movies. The
data was pre-processed according to the CRISP-DM
methodology (Paralič, 2010). The data were manually
annotated. Using a confusion matrix, several
indicators of binary classification efficiency were
quantified in the process of testing. The results of
testing were poor and the processing time was too
high.
To improve the DASA approach, we decided to
utilize possibilities of natural language processing
(NLP).
4.2 DASA Involving NLP
In NLP, the analysed text was partitioned into words
or morphemes according to rules of morphologic
analysis. Our work was oriented on English, because
English has quite simple and regular morphology. We
assumed that relations between words are represented
above all by word-order. A key part of the systems of
natural language processing and also the sentiment
analysis system is a module for parsing.
The parser decomposes a sentence into words and
consequently assigns a word class to each word. It
enables us to generate a parsing tree a structure for
extraction of the meaning of a sentence. A
reoccurring problem was shape homonymy, which
appeared when one word could have multiple
different word classes. In our approach to sentiment
analysis, these homonyms were processed in the
following way. The final value of the polarity of a
homonym was computed as an average of the values
of all occurrences (shapes) of the word.
During sentiment analysis, the most important
words are adjectives, adverbs, nouns and verbs. These
word classes usually express the polarity of an
opinion in the best way. So in our improvement of
DASA, the analysed texts were decomposed into
sentences and sentences were decomposed into
words. Consequently, word classes were assigned to
each word and then only adjectives, adverbs, nouns
and verbs were taken into account during sentiment
analysis.
The implemented approach was tested. Results in
the measures of precision, recall and F1 measure are
presented in Table 3.
Table 3: Results of tests of DASA+NLP approach in
Precision, Recall, F1-measure and Accuracy.
Opinion
Precision
Recall
F1
Accuracy
Positive
0,586
0,612
0,598
-
Negative
0,491
0,568
0,527
-
Average
0,539
0,590
0,563
0,536
The testing was provided on 1000 positive and
1000 negative reviews. The achieved results were
only slightly better and still insufficient. But the time
of processing was cut short by half.
4.3 DASA and NLP Involving New
Methods of Negation and
Intensification Processing
The previous testing results have confirmed that the
results of sentiment analysis cannot be satisfied, when
only separate words are processed. An important part
of sentiment analysis is also the processing of groups
of words, for example for negation (“insufficiently
functional”) or intensification (“very nice graphic
design”). The negation and intensification represents
derivatives of a language. Both negation as well as
intensification can change the polarity of a connected
word (consequently also polarity of the whole text)
and in this way they can increase the precision of
sentiment analysis.
Sentiment Analysis of Web Trends for the Antisocial Behaviour Detection
453
The processing of negation and intensification is
based on information from an external source the
classification lexicon. Our classification lexicon
contains a special part for negation processing (with
words as no, not, never, neither, nobody, none,
nothing, etc.) and a special part for intensification
processing (very, highly, too, most, extremely, etc.).
There are two known main methods for negation
processing: switch negation and shift negation
(Taboada, 2011). Within our approach four various
methods for negation processing were tested:
modification of an opinion polarity by a direct
reverse turn
shifting opinion polarity of related word
change of opinion polarity using a constant value
change of opinion polarity using a percentage
value.
All these methods were implemented and tested.
These tests have shown, that the most suitable and
precise possibility is the method of change of opinion
polarity using a constant value. We have also made
experiments with various constant values. According
to the experiments the best values are PosValue = 0,5
and NegValue = 0,65.
The second improvement of the “lexicon
approach involving NLP and the selected methods for
negation and intensification processing” works in the
following way. It detects words in the analysed text,
which are carriers of opinion (adjectives, adverbs,
nouns and verbs). Consequently, it checks the
existence of possibility of occurrences of negations or
intensifications in the neighbourhood of the
processed words. In the case of positive matching, the
value of the polarity of the processed word is
recomputed. The results of testing of this approach
are presented in the Table 4. The achieved results in
this case were significantly better and sufficient for
using this approach in the dynamic analysis of a web
trend.
Table 4: Results of tests of DASA+NLP involving the
negation and intensification processing
(DASA+NLP+NandI).
Opinion
Precision
Recall
F1
Positive
0,786
0,848
0,816
Negative
0,835
0,769
0,800
Average
0,811
0,809
0,810
Figure 1 illustrates the results of testing of the
following implementations (from left to right):
DASA, DASA+NLP and DASA+NLP+NandI. There
is a gradual improvement of effectiveness. The Recall
has gradually increased and the best implementation
from this point of view is DASA+NLP+NandI.
The processing time has rapidly dropped after
involving NLP (DASA+NLP) to one quarter of the
original time. But the last implementation very
slightly increased the processing time by adding
negation and intensification processing.
Figure 1: An overall evaluation of all tested
implementations (blue for recall and red for processing
time).
The novelty of our approach in comparison with
work (Taboada, 2011) is in the DASA + NLP + NandI
method, which uses original processing of negation
and intensification and also the NLP technique.
There are some other approaches based on
lexicons. For example, (Mohammad, 2016) presents
sentiment lexicons for Arabic social media. They
present several large sentiment lexicons that were
automatically generated using supervision techniques
on Arabic tweets, and translation English sentiment
lexicons into Arabic. The approach is not comparable
to our work.
Another approach in (Labille, 2017) generates a
domain-specific lexicon using probabilities and
information theoretic techniques. Their results are
better than our results. But we used a general lexicon
and usually general lexicons cannot be more precise
in some given domain than the lexicon generated
specifically for this domain.
In the paper (Cambria, 2016), the SenticNet4 is
presented. Authors achieved better results than we,
probably because they used semantically enriched
approaches to sentiment analysis.
Nielsen presents a labelled word list a new
ANEW lexicon, where each word has been scored for
valence, a 'sentiment lexicon' or 'affective word lists'
in (Nielsen, 2011). This interesting approach cannot
KDIR 2019 - 11th International Conference on Knowledge Discovery and Information Retrieval
454
be compared to our approach, because they used
unusual efficiency measure.
5 DYNAMIC ANALYSIS
A dynamic analysis of sentiment plays an important
role in solving real problems. It is more important for
companies, because of the decrease in the cost of the
analysis, its higher precision and wider possibilities
for utilization. So the companies can effectively
obtain a feedback from users.
5.1 Web Forum Selection
As a data source, the discussion on a new mobile
Apple iPhone X was selected. Reviews on this new
product were extracted from the web forum
Gsmarena (Gsmarena, 2018). This mobile was
introduced and brought to marked recently and
specialists consider it to be a revolution among
modern mobiles. The discussion forum Gsmarena
(see Figure 2) was selected because the owner of this
forum is the society which:
does not sell any mobiles
does not offer any recommendations for clients
which mobile to buy
doesn’t have any preferences connected with
mobiles
doesn’t have any profit from mobile sales.
Thus, this web discussion about mobiles is not
influenced by the owner of this discussion forum and
opinions are not modified, preferred or deleted.
Another reason for the selection of Gsmarena forum
was the fact, that millions of unique users are active
on it each day and a great majority of them express
their opinions. Rules were defined for contributing to
the Gsmarena web forum to guarantee valuable and
real reviews.
5.2 Results of the Web Trend Analysis
The text data from Gsmarena were extracted together
with information about time and date of comment
posting and processed using the implementation
DASA+NLP+NandI. During this processing all reviews
were analysed from the point of view of
positivity/negativity of texts. All polarities of all
posts’s texts on the given theme were summarized in
the form of an unweighted normalized sum.
We have obtained information needed for future
dynamic analysis of the web trend connected with
reviews on mobile Apple iPhone X. There are some
details on the dataset presented in the Table 5.
Figure 2: An illustration of Gsmarena web forum.
Table 5: The results of application DASA+NLP+NandI on
data from Gsmarena on the mobile Apple iPhone X.
N
PN
NN
PS
NS
September
833
443
390
0,5318
0,4682
October
361
182
179
0,5042
0,4958
November
543
288
255
0,5304
0,4696
December
252
154
098
0,6111
0,3889
January
157
085
072
0,5414
0,4586
February
136
065
071
0,4779
0,5221
March
025
017
008
0,6800
0,3200
Where:
N is the number of comments extracted from
Gsmarena during the given period
PN is the number of comments from the given period
classified as a positive opinion by application
DASA+NLP+NandI
NN is the number of comments from the given period
classified as a negative opinion by application
DASA+NLP+NandI
PS is PN/N (ratio of the amount of positive opinions
to all opinions)
NS is NN/N (ratio of the amount of negative opinions
to all opinions)
The total number of posts in the dataset was 2307
(1234 positive and 1073 negative posts). The results
from Table 5 were transformed into a graphical form
and illustrated in Figure 3.
Figure 3 represents the dynamic analysis of the
sentiment of the selected web trend. The dynamic
change of the positive opinion is drawn in blue (upper
curve) and the dynamics of the negative opinion in
red (lower curve). Figure 4 represents the same
dynamic analysis, but in this graph only the
differences between positive and negative polarity
values are shown. In Figure 3 and Figure 4, we can
see three turning points. The beginning of the graph
represents the 12 September 2017, when iPhone X
Sentiment Analysis of Web Trends for the Antisocial Behaviour Detection
455
was officially announced. It was the day when a web
discussion about the iPhone started.
Figure 3: Dynamic analysis of a web trend - mobile Apple
iPhone X with separate representation of positive (blue
upper curve) and negative (red lower curve) opinion.
Figure 4: Dynamic analysis of a web trend (mobile Apple
iPhone X) with value of resulting opinion in the form of
difference between positive and negative values.
The first turning point is connected with the date
3 November 2017, when iPhone X was released
which could explain the increase in sentiment from
October to November. From then the summarized
polarity started growing until the second turning
point, when a new actualisation of iPhone X was
rolled out and the Face ID function caused many
errors. Consequently, the summarized polarity
decreased until the third turning point, when all
mistakes in new actualisation were corrected. After
this point the summarized polarity stated to increase
again.
6 CONCLUSIONS
We designed a new approach to web trend analysis.
This design was based on the most important
webometric sentiment analysis. Our new approach
to sentiment analysis based on a lexicon was designed
and improved, to improve precision. This solution
was used for the dynamic analysis of the selected web
trend, which was the new mobile Apple iPhone X.
The dynamic analysis showed a trend which
corresponds to the real life events in the life of this
mobile. We can say that our goals were fulfilled and
for the future we would like to use our experience
with web trends analysis in recognition of antisocial
behaviour in online posting of reviews.
One limitation of this work is that only one
webometric is being considered, which is sentiment
analysis. For future studies other webometrics such as
social networks analysis (SNA) and mention analysis
(MA) might also be used. Another improvement
could be to use the information about an authority or
trolling of the given reviewer to increase the
effectivity of the sentiment analysis (Mikula, 2018).
Our approach could be a core of a future
recommender system (Tarnowska, 2019).
ACKNOWLEDGEMENTS
The work was supported by the Slovak Research and
Development Agency under the contract No. APVV-
16-0213 and the contract No. APVV-17-0267
“Automated Recognition of Antisocial Behaviour in
Online Communities”.
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