Ijraset Journal For Research in Applied Science and Engineering Technology

Abstract

Sentiment Analysis or opinion mining is the computational examination of sentiments, perspectives and emotions conveyed in written language. In recent years, sentiment analysis has become an active study in fields of natural language processing and text mining. The internet is full of textual data in the form of papers, articles and blogs. Sentiment analysis is the best way to extract key information from this data. In this paper we compare classification of tweets using rule based methods, Machine Learning method and Deep Learning method.

Introduction

I. INTRODUCTION

People may communicate their opinions, ideas, sentiments, and judgments on a variety of issues ranging  from education to entertainment, thanks to the introduction  of social media platforms such as Facebook, Twitter,  LinkedIn, and Instagram. These platforms house a massive  quantity of data. 90% of this data is in textual or media  form. Sentiment Analysis is a technique for deducing the  polarity of emotions such as joy, sadness, grief, hatred, rage,  and affection, as well as opinions, from text, reviews, and  postings accessible on these platforms.

Opinion mining for  sentiment analysis identifies a text's sentiment in relation to  a certain source of information. Due to various slang  phrases, wrong spellings, short forms, varied characters,  regional language, repeated characters, and incoming  emojis, sentiment analysis is very complex and ever  growing research field. Social media is one of the places  where we can see effective use of sentiment analysis. 

Efficacy is what makes sentiment analysis very  popular. There are billions of text documents in the world  and sentiment analysis can be carried out of all of them. It is  an accurate process with high success results. A few  applications where sentiment analysis proves to be useful  are:•

Purchasing Merchandise or Service: When buying a certain commodity and/or utility we want to get the perfect option available for us. We can go through the  reviews one by one and find out for ourselves if the  product or service is good enough or we can let a  sentiment analysis algorithm take over this task for  us. This way now we can evaluate reviews or other  text and opinions of any service and/or product.

1. Recommendation System: The algorithm that can  forecast what all items should be suggested according  to user preferences by assessing and classifying  people's opinions based on their preferences and  interests.
2. Quality Reviews and Improvements: Opinion mining  allows manufacturers to gather consumer feedback on  their product or service, whether positive or negative,  and then improve the features and quality as per user  needs..
3. Making a Decision: People's sentiments, thoughts,  and feelings are all crucial factors to consider while  making a decision. When purchasing any item,  whether it is a book, clothing, or electronic devices,  the user first reads the thoughts and reviews of that  product, and these significantly influence customer's  thinking. 
4. Marketing research: Using sentiment analysis in for  market research purpose may be used to assess  customer attitudes toward a product or service, as  well as any new government policy.

The stages of sentiment analysis are as follows:

a. Pre-Processing: The raw data is initially cleaned up.

b. Feature Extraction: The keywords are assigned a token,  which is then subjected to analysis.

c. Classification Phase: These keywords are assigned to one  of several categories based on various methods.

II. LITERATURE REVIEW

Saad and Yang [1] in year 2019 gave way for new  developments in sentiment analysis using machine learning  algorithms. They both put forward a model which  encapsulated preprocessing and feature extraction of tweets.  Support Vector Regression and Multinomial Supply  Regression were used for classification of sentiments. The  results show that the proposed model outperformed others  and earned the simplest accuracy over other methods. Fang  [2] in year 2018 urged a multi-strategy model based on  victimization of the linguistics blurriness for partitioning the  issues. This method increased the model efficiency multiple  folds.

Afzaal [3] in year 2019 proposed a new aspect based approach to sentiment analysis. This method was very  precise and the most effective way to classify the corpus  with maximum accuracy.This model was made for mobile  applications as a result it was also tested on other systems  and proved to be effective in all types of conditions.

Ray and Chakrabarti [4] in year 2019, devised a  deep learning method to extract features from textual Daya  and perform sentiment analysis. A 7 layers Convolution  Neural Network is implemented for feature extraction and  labelling the corpus so as to boost the performance. In this  way simplest accuracy and efficiency was achieved.

Joscha[5] compared varied ways and techniques of  algorithms to boost the performance of sentiment analysis. A

few of these techniques involved algorithms like Bag of  words models and n-grams for mistreatment linguistics data.  The 1st approaches did not consider the relation between  words and took them into account individually without  making a correlation with other words. A. Hogenboom [6]  planned a Rhetoric Structure Theory (RST) tree structure to  do the task of sentiment analysis. They put the binary data in  the random forest. The machine learning implemented  raised the accuracy and efficiency of the model with F1  score of 71.9%.

Xu [7] in year 2020, introduced NB methodology  for multi-domain review classification of sentiment  platform for mainly E-commerce. Similarly this method  was also introduced to learning fashion trends. Upon further  fine tuning and review of algorithm in various real-case  aspects it was found that the algorithm works extremely  well with the Amazon product reviews and picture show  review and give a high accuracy score for same. 

Smadi [8] improved the existing model for  specifying defects based on feature extraction. Firstly, he  conducted this research on Arabic hotel reviews. Aimed to  get the exact sentiments he was able to build a decent model  with provided with high accuracy using the correct features  from the corpus. Secondly, SVM and Deep RNN were  developed and trained with lexical, word, morphological,  semantic, and grammar language features. The dataset of the  Arabic hotel' review dataset was used for evaluating the  given proposed model. The outcomes have shown that SVM  was playing well in comparison to the RNN model. In  2020, Masood explored the impact of assorted patterns  happening within the year of 2012 to 2016 on various stock  markets. In this case, dataset from Twitter was utilized for  computing the sentiment analysis of every one of those  events. The Twitter dataset enclosed many tweets from all  backgrounds that were made for outlining the event  sentiment. 

III. ALGORITHMS FOR SENTIMENT ANALYSIS

A. VADER

VADER ( Valence Aware dictionary for Sentiment  Reasoning) is a NLP algorithm model used for textual  sentiment analysis. The model divides the text data into each  polarity (positive/negative) and the strength of each feeling  or sentiment. This method is applied on unlabelled textual  data and is out there within the NLTK package. VADER  method of sentiment analysis depends on a dictionary that  maps each word options to sentiment referred to as  sentiment scores. The sentiment score of a text is obtained  by summarizing the intensity of every word in the text.

Example - Words like “happy’’, ‘enjoy’, ‘love’ all  shows a positive sentiment, conjointly the model is smart.  The model grasps the underlying meaning of words and  sentences, words like “did not approve’’ is perceived as a  negative statement. VADER is able to understand the stress  of punctuations and capitalisations, such as “FUN ''.

B. SENTIWORDNET

SENTIWORDNET algorithm is an upgarade over  the VADER model and is made from the automatic  annotation of the sets of WORDNET in line with the  polarity of “positivity”, “negativity”, and “neutrality”. Every  textual data(corpus) is associated with 3 numerical scores 

Pos(s), Neg(s), and Obj(s) that indicate how positive,  negative, and “objective” (i.e., neutral) are the terms  contained within corpus. Completely varied senses of a  similar term might have varied sentiment related properties.  Words like not do show a negative impact on the whole  sentence.

C. NAIVE BAYES

Thomas Bayes’ Theorem forms the basis of Naive  Bayes classifier. Naive Bayes classifier works on the  assumption that one feature is completely unrelated to all  other features and moreover they don’t affect each other in  any way. Naive Bayes works on the concept of basic  probability and the model is straightforward to create. It is  useful where very large dataset comes into play. Besides  simple implementations, Naive Bayes exceeds even  extremely subtle classifications.

Naive Bayes is an easy to implement machine  learning model which runs on fundamental concepts of  probability. Equations of Naive Bayes are:

1. P C|X = P(X|C) ∗ P(C)/P(X)
2. P(C|X) = C class posterior probability (3) P(C) = C class probability
3. P(X|C) = probability of predictor given the class. (5) P(X) = predictor probability

IV. EXPERIMENTAL SETUP

We begun by analysing a few research papers and  open-source softwares for sentiment analyzing. We made a  summary and draft pro and cons for each algorithm and  proposed methodology. We studied about classification  algorithms and how they can be used to best fit our use case  in terms to classifying textual data. We studied about  frequently used algorithms for classification.

We used Cornell university movie reviews dataset  also known as Yelp movie review dataset. The dataset  contains 10,000 movie reviews in the form of textual data.  We have attached the dataset in the rt-polaritydata directory  folder inside this repository. This subset is of 5000 positive  reviews and 5000 negative movie reviews. We have built a  rule based binary classifier (using corpus VADER and  SentiwordNet) and machine learning based classifier(Naive  Bayes classifier) to do the comparison between the two.

Next step was to get the dataset into usable format  and ready for our use using the right modifications. This  was done in following steps.

1. Data Processing: Process the raw data, convert it to a  pandas data frame, and manipulate the data according to  your need and save it to another csv file. 
2. Data Vectorisation: The process of converting the  textual dataset to a vector of integers using one hot  encoding(single layer). Deep learning models do not  accept any text based input rather you need to feed the  inputs as integers or floats types. 
3. Data Vocabulary: we need to create a vocabulary for an  NLP sentiment analysis task, because our algorithm can  learn only from the words and corpus it has seen before. So for this reason we need to know the frequency of  words in a text corpus, along with where it appears in the  text. We can easily store this in a python dictionary.
4. Data processing in PyTorch: We process and compute  the data in PyTorch in using torch data loaders. These  automatically converts the dataset in batches for us. We  need not to split the dataset. It also handles the auto-grad  for us. 
5. Batching of the data
6. Shuffling of the data
7. Loading of the data in parallel: using multiprocessing  workers.

With the preprocessing of our data done we next  moved to create our own deep learning model to classify the  tweets. For this classification we choose Convolution  Neural Network (CNN) algorithm because of its adaptability  to change and the latency to be modified easily. Changes in  dimensionality and channels which the CNN algorithm was  the reason to choose this over any other classification  algorithms.

The model here has a goal to find out how many  layers for convolution neural network will be suitable  considering both accuracy and computational power  required to train the model. It is always that the linear (or fc)  layers perform better when it comes to classification of data.

We begin creating the model by constructing a data  tensor and running it on our algorithm. We used a 3 -  dimensional data. If you use a one-hot vector for each  character in a sequence of characters, a sequence of one hot vectors is a matrix, and a mini batch of one-hot  matrices is a three-dimensional tensor. By utilizing the  notion of convolutions, the dimension of every one of one hot vector (the corpus size in general) is same as the number  of “input channels” and the length of the character sequence  is known as the “width.”

Our focus was to present a comparison on normal  algorithms, machine learning algorithms and our deep  learning model. We used the CNN type of deep learning  algorithm due to the numerous variation possibilities which  it offers to modify and fine-tune our model in any way we  want. Theoretically the novice deep learning should have  outperformed the generic algorithm as well as ML model.

The model was trained using a CUDA. Whole of  corpus was divided into train and test dataset and then the  computations were executed.

V. RESULTS

Vader, SentiwordNet and Naive Bayes Algorithm,  were performed on the Data set and these algorithm’s  performance was noted against our deep learning model.

Conclusion

This research was conducted with various algorithms and various techniques were used to determine the emotion and sentiments by deducing the polarity of the corpus (textual dataset). We took use of algorithms like Vader, SentiwordNet, Naive Bayes and CNN. Out of all these algorithms the one which came on top giving the best results was the CNN classifier with the accuracy of 91.30%. As only less algorithms and methodologies were tested against our dataset, it is required to test other ways or create hybrid methods from different algorithms so that accuracy and efficiency of the our model can be increased. Finding the sentiment of the text data can help in various domains. Smart technologies can be developed which can give the users comprehensive analytics about reviews of books, services items, and more without creating a need for them to go and study each reviews one at a time, they can directly take decisions based on the data and analytics given by smart algorithms.

References

[1] S. E. Saad and J. Yang, \"Twitter Sentiment Analysis Based on Ordinal Regression,\" IEEE Access, vol. 7, pp. 163677-163685, (2019) [2] Y. Fang, H. Tan and J. Zhang, \"Multi-Strategy Sentiment Analysis of Consumer Reviews Based on Semantic Fuzziness,\" IEEE Access, vol. 6, pp. 20625-20631, (2018) [3] M. Afzaal, M. Usman and A. Fong, \"Tourism Mobile App With Aspect-Based Sentiment Classification Framework for Tourist Reviews,\" IEEE Transactions on Consumer Electronics, vol. 65, no. 2, pp. 233-242, (2019) [4] ParamitaRay, and AmlanChakrabarti, \"A Mixed approach of Deep Learning method and Rule-Based method to improve Aspect Level Sentiment Analysis\", Applied Computing and Informatics, (2019) [5] Joscha Markle-Huß, Stefan Feuerriegel, Helmut Prendinger, \"Improving Sentiment Analysis with Document Level Semantic Relationships from Rhetoric Discourse Structures\", Proceedings of the 50th Hawaii International Conference on System Sciences, (2017) [6] A. Hogenboom, F. Frasincar, F. de Jong, and U. Kaymak, \"Using Rhetorical Structure in Sentiment Analysis\", Communications of the ACM, vol. 58, no. 7, pp. 69–77, (2015) [7] FengXu, ZhenchunPan, and RuiXia, \"E-commerce product review sentiment classification based on a naïve Bayes continuous learning framework\", Information Processing & Management, (2020) [8] MohammadAl-Smadi, OmarQawasmeh, MahmoudAl Ayyoub, YaserJararweh, and BrijGupta, \"Deep Recurrent neural network vs. support vector machine for aspect based sentiment analysis of Arabic hotels’ reviews\", Journal of Computational Science, vol. 27, pp. 386-393, (2018)

Copyright

Copyright © 2022 Bhanu V Gupta, Varun Singh, C. Lakshmi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.