the form of negative tweets, neutral tweets and
positive tweets. In this study, the Naive Bayes method
and the Support Vector Machine will be used to
obtain sentiment analysis on the implementation of
online learning during the pandemic.
2 THEORY
2.1 Machine Learning
Machine learning is a subset of Computer Science
that makes computers learn from experiences like
humans. This science was developed for
computational learning, pattern recognition, and
information retrieval. One of the main advantages of
machine learning is that computers can be trained to
automate tasks that would be exhausting or
impossible for humans.
It is a branch of artificial intelligence, which
requires the design and development of algorithms
that enable computers that can learn from data and
predict data. Since intelligence requires knowledge,
computers also need to derive knowledge from
empirical data. Machines can be trained to translate
knowledge into features. The extracted features can
be used to develop the model. Machine learning
algorithms make predictions or decisions based on
data by building mathematical models from empirical
data rather than following a predetermined set of
program instructions. In traditional programming
Program and Data Input determine the output,
whereas in Machine Learning the data input and
Output from past instances determine the program.
Machine learning as a computer program that can
learn from experience with respect to several tasks
and required performance measures (Mitchell, 1997).
Tens of thousands of machine learning algorithms
already exist and every year hundreds of new
algorithms are developed. Every machine learning
algorithm has three components called
representation, evaluation and optimization (Luna, et
al., 2011). Representation is a representation of the
model space and is carried out in the form of decision
trees, rule-based programs, Bayes/Markov models,
artificial neural networks, supporting vector
machines and ensemble models. Evaluation is to
measure how effective the algorithm is and is carried
out using measures such as Mean Square Error,
Accuracy, Precision and Recall, Confusion Matrix,
Cost, Utility, Entropy, Maximum Likelihood Error,
Gini Index and KL divergence etc. Optimization, is
how the represented model space is searched to get a
better evaluation.
Machine learning involves two phases, namely
the training phase and the testing phase. In the
training phase, the system learns to complete certain
tasks such as classification or prediction using a
specific data set that contains information about that
particular problem. Based on this learning, the system
is able to analyze new sample data with the same
distribution as the trained data and provide
predictions. In reality, there is no perfect method to
solve a particular problem, because it relies on
empirical data.
Machine learning algorithms are classified into
Unsupervised, Supervised and Reinforcement
Learning algorithms (Putra, 2020). Unsupervised
algorithms learn from unlabeled data, Supervised
algorithms are trained from labeled data, and
Reinforcement Learning algorithms use
environmental information other than learning data
and can make decisions adaptively.
2.2 Sentiment Analysis
Sentiment analysis can aim to extract the polarity of
opinion against an entity from a document, extracting
the polarity of opinion from individual sentences
(Chen, et al., 2019). A large number of sentiment
analysis methods are categorized as rules-based,
machine learning-based, and deep learning-based
methods. The existence of huge amounts of
unstructured data in recent decades has made
sentiment analysis adaptable to new requirements and
methods. Sentiment analysis trends can be grouped
into aspect sentiment analysis, multimodal,
contextual, sentiment reasoning, domain adaptation
and so on (Al-Ghadir, et al., 2020).
2.2 Naïve Bayes
The Naïve Bayes method is a collection of
classification algorithms based on the Bayes
Theorem, commonly used in machine learning. This
method is not a single algorithm but a set of
algorithms that all have the same principle, that each
classified feature does not depend on the value of
other features. For example, a fruit is considered an
apple if it is green, round, and about 6 cm in diameter.
The Naive Bayes classifier considers each of these
features (green, round, 6 cm in diameter) to contribute
independently to the probability that the fruit is an
apple, regardless of any correlation between the
features. However, the features are not always
independent which is often considered as a drawback
of the Naive Bayes algorithm. While this is a
relatively simple idea, Naive Bayes can often