a long way to proceed, developing systems that can
detect emotions from text has many applications.
The intelligent tutoring system can decide on
teaching materials, based on users mental state and
feelings in E-learning applications. The computer can
monitor users emotions to suggest appropriate music
or movies in human computer interaction (
Yadollahi,
Ali and Shahraki, Ameneh Gholipour and Zaiane, Osmar R,
2017)
. Moreover, output of an emotion-mining system
can serve as input to the other systems. For instance,
Rangel and Rosso (
Yadollahi, Ali and Shahraki, Ameneh
Gholipour and Zaiane, Osmar R, 2017 )( Rangel and
Paolo Rosso,2016) use the emotions identified within
the text for author identification, particularly
identifying the writers age and gender. Lastly,
however not the least, psychologists can understand
patients emotions and predict their state of mind
consequently. On a longer period of time, they are
able to detect if a patient is facing depression, stress
that is extremely helpful since he/she can be referred
to counselling services (
Yadollahi, Ali and Shahraki,
Ameneh Gholipour and Zaiane, Osmar R, 2017)
. There is
analysis on detecting emotions from text, facial
expressions, images, speeches, paintings, songs, etc.
Among all, voice recorded speeches and facial
expressions contain the most dominant clues and have
largely been studied (Carlos Busso, Zhigang Deng,
Serdar Yildirim, Murtaza Bulut, Chul Min Lee, Abe
Kazemzadeh, Sungbok Lee, Ulrich Neumann, and
Shrikanth Narayanan, 2004)( Alicja Wieczorkowska,
Piotr Synak, and Zbigniew W. Ra´s., 2006). Some
types of text can convey emotions such as personal
notes, emails, blogs, novels, news headlines, and chat
messages. Specifically, popular social networking
websites such as Facebook, Twitter, Myspace are
appropriate places to share one’s feelings easily and
largely.
1.1 Multi-label Classification for
Emotion Classification
Emotion mining is a multi-label classification
problem that requires predicting several emotion
scores from a given sequence data. Any given
sequence data can possess more than one emotion, so
the problem can be posed as a multi-label
classification problem rather than a multi-class
classification problem. Both machine learning and
deep learning were used in this research to solve the
problem.
1.1.1 Machine Learning based Approach
For the machine learning models, data cleaning,
text preprocessing, stemming, and lemmatization
on the raw data were performed. The text data was
transformed to vectors by using the TF-IDF
method, then multiple methods were used-to
predict each emotion. SVM, Naive Bayes, Random
Forest, and KNN classifiers were used extensively
to build the machine learning solution. After all the
training, various performance metrics measures
were plotted for each model concerning every
emotion label as a bar plot.
1.1.2 Deep Learning based Approach
For the deep learning, dataset is loaded, then
preprocessed, and encoded to perform deep learning
techniques on it. From this research shows that RNN
based model performs well on text data, GRU model
was built with an attention mechanism to solve the
problem by training for multiple epochs to obtain
the best accuracy.
2 DATA AND PREPROCESSING
In this research, 10,983 English tweets were used for
multi-label emotion classification from (“SemEval-
2018”, 2018), (Mohammed, S., M.; Bravo-Marquez,
F.; Salameh, M.; Kiritchenko, S, 2018). The dataset
of emotions classification includes the eight basic
emotions (joy, sadness, anger, fear, trust, disgust,
surprise, and anticipation) as per Plutchik (1980)
(Jabreel M., Moreno A, 2019) emotion model, as well
as a few other emotions that are common in tweets
which are love, optimism, and pessimism. Moreover,
python 3.7.4 version was used for data preprocessing,
multi-label emotion classification, and data
visualization.
Data preprocessing is the most crucial data mining
technique that transforms the raw data into a useful
and efficient format. Real-world information is
frequently inconsistent, incomplete, or missing in
specific behaviours and is likely to contain lots of
errors. It is a demonstrated technique of resolving
such issues. It prepares raw data for further
processing. Different tools are available for data
preprocessing. Data preprocessing is divided into a
few stages which is show in Figure 1.
Multi-label Emotion Classification using Machine Learning and Deep Learning Methods