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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Am I Really Happy When I Write “Happy” in My Post?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Pavel Shashkin</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alexander Porshnev</string-name>
          <email>aporshnev@hse.ru</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>National Research University Higher School of Economics</institution>
        </aff>
      </contrib-group>
      <fpage>126</fpage>
      <lpage>136</lpage>
      <abstract>
        <p>Posts published on the Internet could serve as a valuable source of information regarding emotion. Recommendation systems, stock market forecast and other areas are likely to benefit from the advancement in mood classification. To deal with this task, researchers commonly rely on preassembled lexicons of emotional words. In this paper we discuss the possibility of extracting emotion-specific words from userannotated blog entries. The study is based on analysis of the collection from 14800 Live Journal posts containing the “Current mood” tag, specified by the author. The analysis findings and possible applications are discussed.</p>
      </abstract>
      <kwd-group>
        <kwd>sentiment analysis</kwd>
        <kwd>user-annotated data</kwd>
        <kwd>computational linguistics</kwd>
        <kwd>emotional states</kwd>
        <kwd>psycholinguistics</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>
        Over the last few years, a considerable amount of work has been done to reduce
the overload of user-generated web content [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. The possibility of grouping data
in accordance with sentiment is repeatedly discussed in recent investigations [
        <xref ref-type="bibr" rid="ref2 ref3">2,
3</xref>
        ]. The system capable of extracting emotions inherent in the text is likely to
assist both human-computer and human-human interactions, and help in various
tasks. For example, automatic analysis of emotions could be used in some
applications, such as: recommendation systems (personal emotions expressed during
evaluation could be taken into account), monitoring of psychological user states
(customer satisfaction or diagnostics of potential illness), business intelligence
(evaluation of the emotional tone of comments circulating about one’s company
can be used to improve financial decisions).
      </p>
      <p>Online diaries provide researchers with extremely diverse and manifold data.
Blog entries are rich in deeply personal and subjective content. Unlike other
corpora used in sentiment analysis, "Current Mood" is a text attribute directly
specified by the author at the time of writing, rather than by some independent
annotator. We expect that analysis of user-annotated data could provide new
information about words people use to express their emotional states.</p>
    </sec>
    <sec id="sec-2">
      <title>Related work</title>
      <p>
        Over the past few decades there have been several projects devoted to analysis
of emotions in the Internet posts. For example, a research project for measuring
emotions is “Pulse of a nation” is based on analysis of Twitter messages from
September 2006 to August 2009 [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. In their research, Mislove and coauthors
tried to find places where life is sweet, people are happier, and to reveal the
unhappiest time of a day. Although, we were unable to find scientific articles,
the authors of the “Pulse of a nation” project took part in several TV programs
and published the results in newspapers and periodicals (including The Wall
Street Journal and The New York Times).
      </p>
      <p>
        To measure emotions in each tweet, Mislove and coauthors used the ANEW
word list [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. The methodology of emotion analysis was to calculate a sentiment
score as a ration of the amount of positive messages to that of negative messages.
A message is regarded as positive if it has at least one positive word and as
negative if it has at least one negative word (the same message can be both
negative and positive) [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        The project focused on the expression of happiness in social media was
developed by a group of researchers from the University of Vermont. They tried to
measure happiness in Twitter posts [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <p>First of all, Dodds and his coauthors conducted a survey using Amazon
Mechanical Turks to obtain happiness evaluations of over 10,000 individual words,
representing a tenfold size improvement over similar existing word sets
(chosen by frequency of usage in collected samples of nearly 4.6 billion expressions
posted over a 33 month span). The created words list contains ranks of their
relation to happiness. For example, the top happiness words in their rank are
laughter (rank=1) and happiness (rank=2). Next, they created on-line service
hedonometer.org, which provides real time happiness analytics based on analysis
of frequencies of the words from the list. It is worth mentioning that this service
also has a rank for the word “birthday”, so the expression “Happy Birthday” is
not excluded from analysis.</p>
      <p>
        Lansdall-Welfare, Lampos, and Cristianini tried to measure several emotions
in twitter posts by counting the frequency of emotion-related words in each text
published on a given day [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. They also use a lexical approach and base their
analytics on the word lists extracted from the WordNet Affect ontology [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ].
      </p>
      <p>After this pre-processing Lansdall-Welfare, Lampos, &amp; Cristianini compiled
four word lists containind 146 anger words, 92 fear words, 224 joy words and 115
sadness words. The evaluation of emotions in tweets was based on counting the
amount of tweets containing each word from the compiled list. Lansdall-Welfare,
Lampos, &amp; Cristianini say they do not expect the high frequency of the word
‘happy’ to necessarily signify a happier mood in the population, as this can be
due to expressions of greeting, like “Happy Birthday”. Although they do not filter
this and similar expressions in their analysis.</p>
      <p>We can conclude that the projects running analysis of emotions and moods in
social networks usually use the lexicon methodology based on expert-annotated
words lists.</p>
      <p>
        Application of the lexicon approach based on expert or naïve rating of
emotions in the Internet posts can be supported by the findings made by Gill, Gergle,
French and Oberlander. They examined the ability of naive raters of emotion to
detect one of the eight emotional categories by asking participants to read 50 and
200 word samples of a real blog text and evaluate whether this message expresses
one of the eight emotions: anticipation, acceptance, sadness, disgust, anger, fear,
surprise, joy or being neutral [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. Comparing the results of evaluation by expert
raters and naive experts allowed the conclusion that rater agreement increased
with longer texts, and was high for ratings of joy, disgust, anger and anticipation,
but low for acceptance and ‘neutral’ texts.
      </p>
      <p>Although raters show agreement in annotation of emotions, we can raise a
question about its validity from the psychological perspective. We are not sure
that all people express their emotions in a straightforward way, using words
closest to the chosen mood category.</p>
      <p>
        An interesting study of emotion in the context of a computer-mediated
environment was conducted by Hancock, Landrigan, &amp; Silver [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]. They organized
an experimental study, in which some of the participants were asked to
express either positive (happy) or negative (unhappy) emotions during a chat
conversation, without explicitly describing their (projected) emotional state. Even
though, their chat partners did not know about their instructions and their
emotional state, they could accurately perceive their interlocutor’s emotions.
Linguistic analysis showed that the authors portraying positive emotions used a
greater number of exclamation marks and more words overall. The participants
portraying negative emotions used an increased number of affective words, words
expressing negative feeling, and negations.
      </p>
      <p>In this study the people understand emotions of their partner even if these
emotions were not explicitly expressed. This raises a question: could we extend
the lists of emotional words by analyzing data annotated with the current mood
of an author?</p>
      <p>Analysis of text semantics, therefore, can provide information about user
emotions and we expect analysis of user-annotated data from LiveJournal to
help extend the existing words lists related to emotions.</p>
    </sec>
    <sec id="sec-3">
      <title>Data collection</title>
      <p>We used DuckDuckGo1 search engine in conjunction with "GoogleScraper"2
Python module to make a list of English-speaking LiveJournal users who have
at least once used the "Current Mood" functionality. The list of obtained URLs
is passed down to the web crawler hosted on "import.io"3 platform. Each visited
page is parsed to extract user messages and links to other LiveJournal blogs to
be added to crawling query (e.g. from the comment section). Data collecting
1 https://duckduckgo.com/
2 https://github.com/NikolaiT/GoogleScraper
3 https://import.io/
continues until the specified maximum page depth is reached.</p>
      <sec id="sec-3-1">
        <title>Start URLs</title>
      </sec>
      <sec id="sec-3-2">
        <title>Blog Queue</title>
      </sec>
      <sec id="sec-3-3">
        <title>Extracted Content</title>
      </sec>
      <sec id="sec-3-4">
        <title>Entry Parser</title>
      </sec>
      <sec id="sec-3-5">
        <title>Outgoing Links Fig. 1. Data collection system architecture</title>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Data-set highlights</title>
      <p>For each message in visited blogs we extract a web address, title, text content
and mood tag (usually accompanied by "Current mood:", "Feeling rather:" or
just "Mood:"). Although the presence of subjective content in a title or web
address is questionable, they are needed to identify continuous entries (eg. stories
divided into series of posts). Blog posts, especially the ones with a fair amount
of text, are not as frequent as, say, twitter posts. For that reason we do not use
time stamps and rarely present geolocation data. The acquired dataset contains
14,800 documents tagged with 800 unique mood labels. 6% of the labels were
responsible for 60% of data entries (Figure 2). Average text length is 420 words.
An approximate post count for the average author is 5 messages (Figure 3). The
most popular mood tags are: "accomplished", "cheerful", "tired" and "amused".</p>
    </sec>
    <sec id="sec-5">
      <title>Pre-Processing</title>
      <p>The initial step is to clean data from invalid entries (non-Latin or comprising
only media content). The dictionary is then reduced by transforming everything
to lowercase, stemming words, removing punctuation, stopwords and numbers.
If we find negations, like “don’t”, “didn’t” or “not”, the subsequent token is
replaced by not_token. For example, “they didn’t come” includes three tokens:
“they”, “didn’t”, “come”. We also keep negations as we can expect negative moods
negotiations to carry some additional information. URLs are shortened to their
respective domains and repeating letters (more than three) are reduced to three.
Words and numbers representing time or date are replaced with "time_date".
blah
good merry
complaccent</p>
      <p>full
ecstatic apathetic</p>
      <p>peaceful grateful
csonfused thankfulaggravated sick jubilant
eumbarrassed optimistic relieved</p>
      <p>t determined angry bored horny worried
ixno sseed tnebitcrehmsyteldlelosrwsalgiosnlcvoeaeormddedy ivcsoehuchreunagtirvyedeviopwuisessirdeladzyirrgitiadteddy
a trs nnoerdydisappointed tismhirsty ditzy giggly lethargincervous</p>
      <p>crazy silly crushed
accomplished</p>
      <p>distressed
grumpy</p>
      <p>satisfied
frustrated hot sore</p>
      <p>location pensive ddorky relaxed
curiouscrappy ehgroggyproductive
cranky suthoughtfulbusy
derpressed
geeky
blank
impressed
melancholy
cheerful sad
energetic</p>
      <p>hyper
indescribable uncomfortable
chipper tired amused
awake calm
ing sed
k a
ro l</p>
      <p>e
w p
annoyed
exhaustedhopeful</p>
      <p>bouncy
contemplative
cold okay
happy</p>
      <p>excited
sleepy</p>
      <p>artistic
said
get
around</p>
      <p>way
something
can
even
know
time
now
eyes
just
back
one
like
tired
happy
really
now
face
even
can
head
time
get
said
eyes
know
back
one
just
like
something
can
head
way
get
now
around
know
even
time
eyes
one
back
just
like
After pre-processing the portion of non-sparse terms doubled. Overall
dimensionality of feature space was reduced by more than 3 times.</p>
      <p>
        Fifteen highest word frequencies for 8 most used mood labels are very similar
and do not provide any evidence that people use emotional words to mark their
emotions (Figure 4). We can see that words highly associated with a mood are
not included in the list with top 20 frequencies. For example, it is not often
that messages tagged “Happy” contain “happy” in their body. The list of top 20
words does not contain many words from emotional lists. Words “like”, “one”,
“back” are not put on the list of 10,000 words related to “happy” according to a
Hedonometrics survey [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. They are not included in the list of Affective Norms
for English Words either [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>The TF-IDF coefficient frequently used for document classification can
provide more focused information about semantics of each emotion categories. To
calculate TF-IDF, we joined all documents of the category into one document.
First, the calculated TF-IDF allowed us to find most of the names used in
posts. The words with the highest TF-IDF scores were “leo", "maes",
"vampir", "jare","sandi","gaara", and "roger". After including the names in a list of
stopwords, we received almost the same situation as with calculation of term
frequencies (see Table 1).</p>
      <p>accomplished
hand 505.7
said 447.1
eye 416.0
back 389.8
head 375.5
smile 368.7
look 360.8
say 355.2
robot 353.5
mule 338.5</p>
      <p>tired cheerful sleepy
hand 222.4 artwork 173.3 ghost 342.0
rift 216.7 hand 167.7 hand 170.2
say 191.8 said 154.5 margin 153.3
f*ck 170.9 head 151.1 head 151.1
eye 156.9 eye 142.8 back 144.5
back 155.6 smile 135.7 color 142.3
look 149.5 face 135.2 say 140.1
head 148.6 back 119.3 eye 130.8
doesnt 145.5 look 117.9 superhero 130.0</p>
      <p>said 145.2 lip 110.8 said 125.4
amused
trade 692.7
prize 379.7
ward 143.9
claim 135.6
vote 128.4
said 91.6
hand 86.6</p>
      <p>bill 86.0
materia 79.7
back 69.4</p>
      <p>happy busy bouncy
array 279.9 dev 263.9 sampl 120.7
hand 164.9 alt 178.5 hand 115.1</p>
      <p>eye 164.7 hand 148.6 introspect 106.3
back 137.1 said 147.0 head 91.3</p>
      <p>lip 127.4 border 133.4 back 89.4
smile 125.5 back 118.3 said 84.8
head 122.0 head 114.8 charact 80.6
knew 122.0 eye 114.7 lip 76.5
realis 121.2 knew 101.3 look 74.6</p>
      <p>face 119.1 multi 101.1 kiss 74.4</p>
      <p>Next, we introduced the TF-ICF coefficient. In order to identify important
group-specific words, the term frequencies T F ij for word i in group j are
multiplied by:
log</p>
      <p>||D||
P||D||
j=1 maxt∈Tj T Ftj</p>
      <p>T Fij
where ||D|| is the number of document groups and Tj - unique words in document
group j.</p>
      <p>The results produced by this transformation are listed in Figure 5 (apart
from persons, locations and brands on top of the list) and provide more
information regarding sentiment. For example, the word "finally" has a high value in
documents tagged with "accomplished" or "tired". Although, some of these
results are relatively counter-intuitive or even contradictory (e.g. "bed" is present
in "accomplished", "bouncy", "cheerful", "busy", but absent in "sleepy").</p>
      <p>This suggests that the distance between documents written in different
emotional states could be shorter than that between documents written in the same
emotional state by different authors. To test this hypothesis, we filtered
documents by author and then, using vector representation of documents, we
calcu(1)
turned
part
bed
maybe
yeah
mouth
okay
says
looks
finally
help
fingers
words
keep
moment
part
better
mouth
looks
says
knows
fingers
arm
kind
okay
help
behind
shoulder
color
ghost
without
okay
mouth
yeah
almost
f*ck
says
might
looks
work
knows
open
already
three
f*cking
maybe
side
body
without
might
tried
almost
words
mind
came
place
keep
behind
work
world
tired
lated cosine similarity between every pair of documents. The same procedure
was carried out for documents filtered by current mood tag.</p>
      <p>The only pair of tags "nervous" and "accomplished" has the distance between
mood labels shorter than the average distance between different authors. This is
probably because they carry a lot of objective content, which should have been
filtered at earlier stages. The previously mentioned self-containing states of mind
fall within the same group of labels, whose distances do not exceed the global
average.</p>
      <p>
        The vector model, therefore, contained enough information to distinguish
emotions and what we needed was to find an approach to extracting words
with maximum information. To solve this task, we used the Mutual Information
feature selection algorithm [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ].
      </p>
      <p>Application of the mutual information feature selection algorithm showed
that the word “happy” provided relevant information about the mood of an
author. However, the top twelve terms for the “happy” category only contained
two emotional words included in the Hedonometics or ANEW list (“happy” and
“wonder”).</p>
      <p>
        We saw that, according to mutual information feature selection, many of
the categories were determined by the terms not included in emotional words
lists. Then we checked whether or not category name synonyms obtained from
WordNet were frequently encountered in the documents labeled with the same
mood [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. Most of the time mood was not specified in the text in an obvious
accomplished
      </p>
      <p>eye 0.0084
head 0.0080
pull 0.0079
turn 0.0074
smile 0.0072
arm 0.0071
first 0.0070
pair 0.0069
behind 0.0069
hand 0.0068
away 0.0067
side 0.0063</p>
      <p>tired
three 0.0014</p>
      <p>got 0.0011
home 0.0010
day 0.0010
lot 0.0009
tell 0.0009
realli 0.0009</p>
      <p>far 0.0008
think 0.0008</p>
      <p>let 0.0008
time 0.0008
part 0.0008
cheerful sleepy
yes 0.0005 found 0.0009
feel 0.0004 name 0.0007
still 0.0004 probabl 0.0007
like 0.0004 knew 0.0007
way 0.0003 side 0.0006
right 0.0003 bad 0.0006
see 0.0003 tri 0.0006
guy 0.0003 rate 0.0006
think 0.0003 time 0.0005
girl 0.0003 walk 0.0005
hold 0.0002 mayb 0.0005
just 0.0002 find 0.0005
way. Only 14 of 50 popular moods or their synonyms are frequently encountered
in a text tagged with the same mood: crazy (stressed, crazy, sick), curious (good,
curious, sore), depressed (depressed, hopeful, artistic), ecstatic (hopeful, ecstatic,
productive), hopeful (hopeful, crazy, sad), pissed off (pissed off, nervous, okay),
sad (sad, frustrated, pissed), sick (confused, crazy, sick), sleepy (stressed, sleepy,
sick), sore (sad, ecstatic, sore), stressed (stressed, depressed, curious).</p>
      <p>Surprised by such results, we tried to analyze the document using words
from the Hedonometrics list. Analysis of frequencies of top twelve words from
the Hedonometrics list in texts written in different moods showed that these
words have the most common usage in emotional states different from “happy”
(Table 3). Only one word “successful” is used more frequently by authors who
tagged their message with the current mood “happy”.
laughter
love
happy
laugh
excellent
joy
successful
win
rainbow
smile
won
pleasure
celebration
Analysis of user-annotated blog messages showed that connections between
emotions and their linguistic expression could not necessarily be straightforward as
is usually expected by compilers of emotional words lists. The most frequent
words in each mood category are not included in the list of emotional terms.
Application of TF-IDF and the calculated TF-ICF coefficient did not change
the situation. Words with the highest scores continue not to be included in
popular lists used for mood analysis. Application of the Mutual Information feature
selection algorithm allowed us to find the most important words in each category,
but only few of them are included in popular lists of emotional words. We can
confirm that. according to the mutual information coefficient, the word “happy”
has high discriminative power, while other words from the Hedonometrics list
were not as successful.</p>
      <p>People show a high ability to evaluate emotions of other persons even in
a computer-mediated environment, although the way we can understand other
people’s emotions still raises questions. On the one hand, the ability to
understand emotions also exists in situations where emotions are not explicitly
expressed; on the other hand, our analysis showed a paradoxical situation when
the terms used for evaluation of emotions are not among the top 20 frequent
or discriminative words for each of mood categories. These facts raise a
question about psychological validity of straightforward techniques for measuring
emotions.</p>
      <p>In our further research we plan to move in two different directions. One is to
compare results of emotion analysis by applying the classical lexical approach
with two dictionaries (ANEW and Hedonometrcs) and Naïve Bayes algorithm
using the probabilities calculated in the current research. The other direction
is to test agreement between naïve or expert annotators and authors of mood
labels. We also intend to develop more sophisticated procedures to filter objective
content and detect invalid entries, establish a meaningful connection between
content and label and further extend our database to improve validity of our
study.</p>
    </sec>
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