=Paper= {{Paper |id=Vol-1452/paper15 |storemode=property |title=Am I Really Happy When I Write "Happy" in My Post? |pdfUrl=https://ceur-ws.org/Vol-1452/paper15.pdf |volume=Vol-1452 |dblpUrl=https://dblp.org/rec/conf/aist/ShashkinP15 }} ==Am I Really Happy When I Write "Happy" in My Post?== https://ceur-ws.org/Vol-1452/paper15.pdf
Am I Really Happy When I Write “Happy” in My
                   Post?

                    Pavel Shashkin and Alexander Porshnev

             National Research University Higher School of Economics
                        p-sh@live.ru, aporshnev@hse.ru



      Abstract. 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 advance-
      ment in mood classification. To deal with this task, researchers com-
      monly rely on preassembled lexicons of emotional words. In this paper
      we discuss the possibility of extracting emotion-specific words from user-
      annotated blog entries. The study is based on analysis of the collection
      from 14800 Live Journal posts containing the “Current mood” tag, spec-
      ified by the author. The analysis findings and possible applications are
      discussed.

      Keywords: sentiment analysis, user-annotated data, computational lin-
      guistics, emotional states, psycholinguistics


Introduction

Over the last few years, a considerable amount of work has been done to reduce
the overload of user-generated web content [1]. The possibility of grouping data
in accordance with sentiment is repeatedly discussed in recent investigations [2,
3]. 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 appli-
cations, 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).

    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.




                                           126
Related work
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 [4]. 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).
    To measure emotions in each tweet, Mislove and coauthors used the ANEW
word list [5]. 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) [6].
    The project focused on the expression of happiness in social media was de-
veloped by a group of researchers from the University of Vermont. They tried to
measure happiness in Twitter posts [7].
    First of all, Dodds and his coauthors conducted a survey using Amazon Me-
chanical Turks to obtain happiness evaluations of over 10,000 individual words,
representing a tenfold size improvement over similar existing word sets (cho-
sen 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.
    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 [8]. They also use a lexical approach and base their
analytics on the word lists extracted from the WordNet Affect ontology [9].
    After this pre-processing Lansdall-Welfare, Lampos, & 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, & 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.
    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.




                                         127
    Application of the lexicon approach based on expert or naïve rating of emo-
tions 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 [10]. 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.
    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.
    An interesting study of emotion in the context of a computer-mediated en-
vironment was conducted by Hancock, Landrigan, & Silver [11]. They organized
an experimental study, in which some of the participants were asked to ex-
press either positive (happy) or negative (unhappy) emotions during a chat con-
versation, 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.
    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?
    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.


Data collection

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/




                                          128
continues until the specified maximum page depth is reached.



                                              Extracted
                           Start URLs
                                               Content


                                                 Entry
                           Blog Queue
                                                 Parser


                                                Outgoing
                                                 Links

                     Fig. 1. Data collection system architecture




Data-set highlights

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".


Pre-Processing

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 re-
placed 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".




                                          129
                                             contemplative                                                happy
                                                                   cold okay excited
                                   exhausted hopeful
                         annoyed bouncy sleepy artistic
                                                                                               peaceful grateful
                                     confused optimistic
                                anxious
                                     embarrassed
                                                  thankfulaggravated                                                     sick jubilant
                                                                                 relieved
                        blah                    content     determined             angry           boredweird worried               horny
                                          stressed




                                                                                 mischievous
                                                             mellow gloomy
                                                          bitchy drained
                                                          restless loved
                                                                                                creative pissedlazyirritated
                                                                                                                     giddy
                                                                    scared
                                                      nerdy disappointed                            hungrydevious
                                                                                                        giggly lethargic                      nervous
                            good                  merry    full                           thirsty ditzy
                                                                                                   crazy silly
                                          complacent   ecstatic apathetic                                                              crushed




                                                                                                                                                   pleased
                        accomplished

                                                                                                                                                   working
                            distressed                     location pensive         dorky       relaxed
                                                                              rushed


                          grumpy                                                                         geeky
                                              curious crappy                            groggyproductive
                                    cranky satisfied
                                frustrated hot sore                       depressed
                                                                                         thoughtful
                                                                                                                       busy blank       impressed
                                                                                                                                hyper
                                                   cheerful sad
                                          melancholy

                                               indescribable           uncomfortable
                                                                                                                        energetic

                                              chipper tired amused
                                                         calm
                                                          awake
                                                                 Fig. 2. Label frequencies


                          Number of sentences                                                                                   Number of words
                                                                                                          0.0030
             0.04




                                                                                                          0.0020
   Density




                                                                                                Density
                                                                                                          0.0010
             0.02




                                                                                                          0.0000
             0.00




                    0           50                         100           150                                       0      500         1000        1500       2000   2500




                           Words in sentence                                                                                        Entries per user
             0.06




                                                                                                          0.15
             0.04




                                                                                                          0.10
   Density




                                                                                                Density
             0.02




                                                                                                          0.05
             0.00




                                                                                                          0.00




                    0      10                        20           30                                               0            5            10              15       20




Fig. 3. Empirical distribution density for text statistics (sentences detected with
openNLP, outliers removed)




                                                                                                  130
                accomplished                tired                 amused                   cheerful
    around                       said                  even                     really
      head                         still               eyes                       now
       way                 something                      got                     face
       now                      eyes                  really                     even
      even                     really                   now                        can
         get                    even                     can                     head
       said                        get                    get                     time
      know                       can                   know                         get
       time                      now                    time                      said
      eyes                     know                     said                     eyes
        can                     time                   back                     know
        one                      one                 traded                      back
      back                      back                      like                     one
        just                      just                   one                       just
         like                      like                  just                       like

                   happy                    sleepy                 busy                    bouncy
       said                       even                    still            something
         get                       said                head                       can
    around                        says                 even                     head
       way                       really              around                      way
 something                         now                   can                       get
        can                       eyes                    get                    now
      even                        head                 eyes                   around
      know                           get                now                     know
       time                         can                 time                    even
       now                         time                know                      time
      eyes                       know                   said                    eyes
        just                        one                  one                      one
      back                        back                   just                   back
        one                         just               back                       just
         like                        like                 like                     like



                Fig. 4. Word frequencies distribution for popular mood labels




After pre-processing the portion of non-sparse terms doubled. Overall dimen-
sionality of feature space was reduced by more than 3 times.
    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 [7]. They are not included in the list of Affective Norms
for English Words either [5].

    The TF-IDF coefficient frequently used for document classification can pro-
vide 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", "vam-
pir", "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).




                                                     131
            accomplished     tired      cheerful         sleepy
               hand 505.7  hand 222.4 artwork 173.3      ghost 342.0
                said 447.1   rift 216.7  hand 167.7       hand 170.2
                 eye 416.0   say 191.8    said 154.5   margin 153.3
               back 389.8   f*ck 170.9   head 151.1       head 151.1
               head 375.5    eye 156.9     eye 142.8      back 144.5
              smile 368.7   back 155.6 smile 135.7        color 142.3
                look 360.8  look 149.5    face 135.2        say 140.1
                 say 355.2 head 148.6    back 119.3         eye 130.8
              robot 353.5 doesnt 145.5    look 117.9 superhero 130.0
               mule 338.5   said 145.2      lip 110.8      said 125.4

               amused          happy          busy         bouncy
             trade 692.7     array 279.9      dev 263.9    sampl 120.7
              prize 379.7    hand 164.9        alt 178.5    hand 115.1
              ward 143.9        eye 164.7   hand 148.6 introspect 106.3
             claim 135.6      back 137.1     said 147.0      head 91.3
               vote 128.4        lip 127.4 border 133.4      back 89.4
               said 91.6     smile 125.5     back 118.3       said 84.8
              hand 86.6       head 122.0    head 114.8 charact 80.6
                bill 86.0    knew 122.0       eye 114.7        lip 76.5
            materia 79.7     realis 121.2 knew 101.3         look 74.6
              back 69.4        face 119.1 multi 101.1         kiss 74.4

Table 1. Words with highest TF-IDF score for eight most popular mood labels (with
proper nouns removed)




    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 mul-
tiplied by:
                                        ||D||
                            log                                              (1)
                                P||D||     T Fij
                                  j=1
                                       maxt∈Tj T Ftj
where ||D|| is the number of document groups and Tj - unique words in document
group j.
    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 infor-
mation regarding sentiment. For example, the word "finally" has a high value in
documents tagged with "accomplished" or "tired". Although, some of these re-
sults are relatively counter-intuitive or even contradictory (e.g. "bed" is present
in "accomplished", "bouncy", "cheerful", "busy", but absent in "sleepy").
    This suggests that the distance between documents written in different emo-
tional states could be shorter than that between documents written in the same
emotional state by different authors. To test this hypothesis, we filtered docu-
ments by author and then, using vector representation of documents, we calcu-




                                         132
                 accomplished               tired                cheerful                  amused
      turned                    without                turned                     body
          part                      okay              maybe                     turned
          bed                    mouth                   says                    better
     maybe                         yeah                 better                 without
         yeah                    almost                 looks                     yeah
      mouth                          f*ck                 hair                   words
         okay                       says                  bed                  fingers
         says                     might                mouth                everything
        looks                     looks                  okay                     mind
       finally                      work                 yeah                       boy
          help                   knows                wanted                        told
     fingers                       open                   kind                      talk
       words                    already               almost                       stop
         keep                      three                   put                   name
    moment                      f*cking                  arms                     gave

                    sleepy                  happy                 busy                     bouncy
          part                  maybe                  turned                     says
        better                     side                   side              everything
       mouth                      body                    bed                      part
        looks                   without                   part                     bed
         says                    might                    help                     hair
       knows                       tried                place                    body
      fingers                   almost                  might                   better
          arm                    words                   mind                  without
          kind                    mind                     put                    side
         okay                    came                   came                      kind
          help                   place                 getting                   arms
      behind                      keep                 please                   series
    shoulder                    behind               probably                      end
         color                     work                   best                 making
        ghost                    world                  found                       bit



  Fig. 5. Most important words according to TF ICF (with proper nouns removed)



lated cosine similarity between every pair of documents. The same procedure
was carried out for documents filtered by current mood tag.
     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.
     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 [12].
     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”).
     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 [13]. Most of the time mood was not specified in the text in an obvious




                                                    133
           accomplished         tired           cheerful           sleepy
               eye 0.0084    three 0.0014           yes 0.0005 found 0.0009
             head 0.0080        got 0.0011         feel 0.0004 name 0.0007
              pull 0.0079    home 0.0010          still 0.0004 probabl 0.0007
             turn 0.0074       day 0.0010          like 0.0004 knew 0.0007
            smile 0.0072         lot 0.0009       way 0.0003       side 0.0006
              arm 0.0071        tell 0.0009      right 0.0003      bad 0.0006
              first 0.0070   realli 0.0009          see 0.0003       tri 0.0006
              pair 0.0069       far 0.0008         guy 0.0003      rate 0.0006
           behind 0.0069     think 0.0008       think 0.0003      time 0.0005
            hand 0.0068          let 0.0008        girl 0.0003    walk 0.0005
            away 0.0067       time 0.0008         hold 0.0002 mayb 0.0005
              side 0.0063     part 0.0008         just 0.0002      find 0.0005

               amused         happy            busy          bouncy
             knew 0.0008    happi 0.0020     thank 0.0012    your 0.0006
               still 0.0008  dont 0.0006        set 0.0011      far 0.0006
              way 0.0007    found 0.0005      pleas 0.0010 someon 0.0005
             week 0.0007        ive 0.0005      use 0.0010     feel 0.0004
              cant 0.0007 wonder 0.0004       everi 0.0010     ask 0.0004
             pleas 0.0007   thank 0.0004        ask 0.0009    sinc 0.0003
               feel 0.0007    wait 0.0004      man 0.0009     talk 0.0003
                far 0.0006    also 0.0004        ill 0.0007  word 0.0003
               will 0.0006  home 0.0004        leav 0.0007   dont 0.0003
                tri 0.0005     one 0.0004    found 0.0007     guy 0.0003
            found 0.0005      isnt 0.0003 comment 0.0006      way 0.0003
               day 0.0005     day 0.0003        tag 0.0006      see 0.0003

Table 2. Most important words according to mutual information feature selection al-
gorithm




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).

   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”.




                                              134
              accomplished tired cheerful sleepy amused happy busy bouncy
laughter           1.37     1.45   1.28     1.16  2.22   1.54 1.61   2.25
love              23.97    25.32 29.18     20.92 27.27 27.29 26.46 30.04
happy              7.28     6.74   8.90     7.98  7.83   11.95 7.71 12.14
laugh             10.83    12.03 12.43      7.28  9.79   7.48 8.88   9.01
excellent          0.50     0.33   0.56     0.54  0.26   0.46 0.54   0.38
joy                0.89     0.66   1.52     0.77  1.17   1.31 0.45   1.25
successful         0.64     1.06   0.72     0.62  0.65   1.39 0.45   0.13
win                1.42     1.19   1.20     0.85  3.26   0.92 1.97   0.75
rainbow            0.56     0.20   0.32     0.31  0.26   0.08 0.09   0.50
smile             27.29    25.45 28.86     21.23 23.10 25.67 20.63 24.53
won                0.73     0.60   1.20     0.46  0.91   0.39 0.90   1.25
pleasure           1.59     1.26   1.60     1.24  1.04   1.46 1.97   3.13
celebration        1.14     1.12   1.92     0.54  1.30   0.69 1.17   0.75

                         Table 3. Word frequencies ×105




Conclusion

Analysis of user-annotated blog messages showed that connections between emo-
tions 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 pop-
ular 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.
    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 un-
derstand 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 ques-
tion about psychological validity of straightforward techniques for measuring
emotions.
    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




                                         135
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.


References
 1. Agichtein, E., Castillo, C., Donato, D., Gionis, A., Mishne, G.: Finding high-quality
    content in social media. In: Proceedings of the 2008 International Conference on
    Web Search and Data Mining, ACM (2008) 183–194
 2. Pang, B., Lee, L., Vaithyanathan, S.: Thumbs up?: Sentiment classification us-
    ing machine learning techniques. In: Proceedings of the ACL-02 Conference on
    Empirical Methods in Natural Language Processing - Volume 10. EMNLP ’02,
    Stroudsburg, PA, USA, Association for Computational Linguistics (2002) 79–86
 3. Yu, L.C., Wu, J.L., Chang, P.C., Chu, H.S.: Using a contextual entropy model to
    expand emotion words and their intensity for the sentiment classification of stock
    market news. Know.-Based Syst. (March 2013) 89–97
 4. Mislove, A., Lehmann, S., Ahn, Y.Y., Onnela, J.P., Rosenquist, J.: Pulse of the
    Nation: U.S. Mood Throughout the Day inferred from Twitter (2010)
 5. Bradley, M.M., Lang, P.J.: Affective norms for English words (ANEW): Instruction
    manual and affective ratings. Technical report, Technical Report C-1, The Center
    for Research in Psychophysiology, University of Florida (1999)
 6. O’Connor, B., Balasubramanyan, R., Routledge, B.R., Smith, N.A.: From tweets
    to polls: Linking text sentiment to public opinion time series. In: Proceedings of
    the International AAAI Conference on Weblogs and Social Media. (2010) 122–129
 7. Dodds, P.S., Harris, K.D., Kloumann, I.M., Bliss, C.A., Danforth, C.M.: Temporal
    patterns of happiness and information in a global social network: Hedonometrics
    and Twitter. PloS one (2011)
 8. Lansdall-Welfare, T., Lampos, V., Cristianini, N.: Effects of the Recession on
    Public Mood in the UK. In: Proceedings of the 21st international conference
    companion on World Wide Web, ACM (2012) 1221–1226
 9. Strapparava, C., Valitutti, A., Stock, O.: The affective weight of lexicon. In:
    Proceedings of the Fifth International Conference on Language Resources and
    Evaluation. (2006) 423–426
10. Gill, A.J., Gergle, D., French, R.M., Oberlander, J.: Emotion rating from short blog
    texts. In: Proceedings of the SIGCHI Conference on Human Factors in Computing
    Systems, ACM (2008) 1121–1124
11. Hancock, J.T., Landrigan, C., Silver, C.: Expressing emotion in text-based commu-
    nication. In: Proceedings of the SIGCHI conference on human factors in computing
    systems, ACM (2007) 929–932
12. Manning, C.D., Raghavan, P., Schütze, H.: Introduction to information retrieval.
    Volume 1. Cambridge university press Cambridge (2008)
13. Miller, G.A.: Wordnet: A lexical database for english. Commun. ACM (November
    1995) 39–41




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