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Sentiment lexicon plays an important role in determining the polarity of words and proves to be an important component in sentiment analysis applications. Most of these sentiment lexicons assign a fixed polarity to each word. However, it has been noted that the polarity of words depends on how they are used and so these lexicons are unable to accurately classify the polarity of the sentiments. By considering the aspect and domain of a word will allow us to more accurately classify sentiments. This paper presents a fully automatic method to build an aspect and domain sensitive sentiment lexicon which assigns a polarity to a word depending on both the aspect and the domain. The experimental results show that our lexicon significantly outperforms other commonly used sentiment lexicons / state-of-the-art approaches. To the best of our knowledge, such a lexicon is not publicly available. As such, we also make this lexicon publicly available as we believe it will benefit the research community. In addition, we observe the long tail distribution behavior of product aspects and propose the possibility of aspect ranking by comparing the number of domains and number of sentiment words present for an aspect.

Learners’ opinions constitute an important source of information that can be useful to teachers and educational instructors in order to improve learning procedures and training activities. By analyzing learners’ actions and extracting data related to their learning behavior, educators can specify proper learning approaches to stimulate learners’ interest and contribute to constructive monitoring of learning progress during the course or to improve future courses. Learners-generated content and their feedback and comments can provide indicative information about the educational procedures that they attended and the training activities that they participated in. Educational systems must possess mechanisms to analyze learners’ comments and automatically specify their opinions and attitude towards the courses and the learning activities that are offered to them. This paper describes a Greek language sentiment analysis system that analyzes texts written in Greek language and generates feature vectors which together with classification algorithms give us the opportunity to classify Greek texts based on the personal opinion and the degree of satisfaction expressed. The sentiment analysis module has been integrated into the hybrid educational systems of the Greek school network that offers life-long learning courses. The module offers a wide range of possibilities to lecturers, policymakers and educational institutes that participate in the training procedure and offers life-long learning courses, to understand how their learners perceive learning activities and specify what aspects of the learning activities they liked and disliked. The experimental study show quite interesting results regarding the performance of the sentiment analysis methodology and the specification of users’ opinions and satisfaction. The feature analysis demonstrates interesting findings regarding the characteristics that provide indicative information for opinion analysis and embeddings combined with deep learning approaches yield satisfactory results.

Opinions have a relevant inuence on people’s behavior. The Internet and the Web have made it possible for people to share their opinions and for other people and organizations find out more about opinions and experiences from individuals. Still, opinions involve sentiments that are vague and imprecise textual descriptions. Hence, due to the nature of the data, Fuzzy Logic can be a promising approach. This paper proposes a method to automatically build a fuzzy system, based on features extracted and selected from documents, to perform classification of sentiment in opinions across different domains. Almost 60 features were extracted from documents and multiple feature selection algorithms were applied. Over the selected features, the Wang-Mendel (WM) method was used to generate fuzzy rules and classify documents. Variations on fuzzy set modeling, on the use of weights in the rules and on fuzzy inference mechanisms were considered. The classifier fuzzy system based achieved 71,25% of accuracy in a 10-fold cross-validation, comparable to a SVM classifier.

Sentiment Analysis or in particular social network analysis (SNA) is a new research area which is increased explosively. This domain has become a very active research issue in data mining and natural language processing. Sentiment analysis (opinion mining) consists in analyzing and extracting emotions, opinions or attitudes from product’s reviews, movie's reviews, etc., and classify them into classes such as positive, negative and neutral, or extract the degree of importance (polarity). In this paper, we propose a new hybrid approach for classifying tweets into classes based on fuzzy logic and a lexicon based approach using SentiWordnet. Our approach consists in classifying tweets according to three classes: positive, negative or neutral, using SentiWordNet and the fuzzy logic with its three important steps: Fuzzification, Rule Inference/aggregation, and Defuzzification. The dataset of tweets to classify and the result of the classification are stored in the Hadoop Distributed File System (HDFS), and we use the Hadoop MapReduce for the application of our proposal.

We propose a mutual information approach to identify feature-based opinion expressions in customer reviews. Associations between opinion words and product feature categories are built by this approach. With the association set, we can identify what product feature a review unit refers to, even in the condition without explicit appearance of feature words. It can also be used to judge the semantic relatedness between a feature word and opinion words in its context. Thus it helps to decide which opinion word should contribute its polarity to the review feature. We also introduce the construction of a polarity lexicon, which is applied to identify opinion expressions in reviews. Using the approach proposed in this paper, we supply the polarity lexicon with the related product feature information. With the resource, we can get a better opinion mining result for a product review from different feature aspects.

Today, smartphones are being used to manage almost all aspects of our lives, ranging from personal to professional. Different users have different requirements and preferences while selecting a smartphone. There is ‘no one-size fits all’ remedy when it comes to smartphones. Additionally, the availability of a wide variety of smartphones in the market makes it difficult for the user to select the best one. The use of only product ratings to choose the best smartphone is not sufficient because the interpretation of such ratings can be quite vague and ambiguous. In this paper, reviews of products are incorporated into the decision-making process in order to select the best product for a recommendation. The top five different brands of smartphones are considered for a case study. The proposed system, then, analyses the customer reviews of these smartphones from two online platforms, Flipkart and Amazon, using sentiment analysis techniques. Next, it uses a hybrid MCDM approach, where characteristics of AHP and TOPSIS methods are combined to evaluate the best smartphones from a list of five alternatives and recommend the best product. The result shows that brand1 smartphone is considered to be the best smartphone among five smartphones based on four important decision criteria. The result of the proposed system is also validated by manually annotated customer reviews of the smartphone by experts. It shows that recommendation of the best product by the proposed system matches the experts’ ranking. Thus, the proposed system can be a useful decision support tool for the best smartphone recommendation.

Sentiment analysis has the potential to significantly impact several fields, such as trade, politics, and opinion extraction. Topic modeling is an intriguing concept used in emotion detection. Latent Dirichlet Allocation is an important algorithm in this subject. It investigates the semantic associations between terms in a text document and takes into account the influence of a subject on a word. Joint Sentiment-Topic model is a framework based on Latent Dirichlet Allocation method that investigates the influence of subjects and emotions on words. The emotion parameter is insufficient, and additional factors may be valuable in performance enhancement. This study presents two novel topic models that extend and improve Joint Sentiment-Topic model through a new parameter (the author’s view). The proposed methods care about the author’s inherent characteristics, which is the most important factor in writing a comment. The proposed models consider the effect of the author’s view on words in a text document. The author’s view means that the author creates an opinion in his mind about a product/thing before selecting the words for expressing the opinion. The new parameter has an immense effect on model accuracy regarding evaluation results. The first proposed method is author’s View-based Joint Sentiment-Topic model for Multi-domain. According to the evaluation results, the highest accuracy value in the first method is equal to 85%. It also has a lower perplexity value than other methods. The second proposed method is Author’s View-based Joint Sentiment-Topic model for Single-domain. According to the evaluation results, it achieves the highest accuracy with 95%. The proposed methods perform better than baseline methods with different topic number settings, especially the second method with 95% accuracy. The second method is a version of the first one, which outperforms baseline methods in terms of accuracy. These results demonstrate that the parameter of the author’s view improves sentiment classification at the document level. While not requiring labeled data, the proposed methods are more accurate than discriminative models such as Support Vector Machine (SVM) and logistic regression, based on the evaluation section’s outcomes. The proposed methods are simple with a low number of parameters. While providing a broad perception of connections between different words in documents of a single collection (single-domain) or multiple collections (multi-domain), the proposed methods have prepared solutions for two different situations (single-domain and multi-domain). The first proposed method is suitable for multi-domain datasets, but the second proposed method is suitable for single-domain datasets. While detecting emotion at the document level, the proposed models improve evaluation results compared to the baseline models. Eight datasets with different sizes have been used in implementations. For evaluations, this study uses sentiment analysis at the document level, perplexity, and topic coherency. Also, to see if the outcomes of the suggested models are statistically different from those of other algorithms, the Friedman test, a statistical analysis, is employed.

One can either use machine learning techniques or lexicons to undertake sentiment analysis. Machine learning techniques include text classification algorithms like SVM, naive Bayes, decision tree or logistic regression, whereas lexicon-based sentiment analysis uses either general or domain-based lexicons. In this paper, we investigate the effectiveness of domain lexicons vis-à-vis general lexicon, wherein we have performed aspect-level sentiment analysis on data from three different domains, viz. car, guitar and book. While it is intuitive that domain lexicons will always perform better than general lexicons, the actual performance however may depend on the richness of the concerned domain lexicon as well as the text analysed. We used the general lexicon SentiWordNet and the corresponding domain lexicons in the aforesaid domains to compare their relative performances. The results indicate that domain lexicon used along with general lexicon performs better as compared to general lexicon or domain lexicon, when used alone. They also suggest that the performance of domain lexicons depends on the text content; and also on whether the language involves technical or non-technical words in the concerned domain. This paper makes a case for development of domain lexicons across various domains for improved performance, while gathering that they might not always perform better. It further highlights that the importance of general lexicons cannot be underestimated — the best results for aspect-level sentiment analysis are obtained, as per this paper, when both the domain and general lexicons are used side by side.

Sentiment classification is the process of classifying emotions and opinions in texts. In this study, the problem of Arabic sentiment analysis was addressed. A support vector machine (SVM) model was proposed to classify opinions in Arabic micro-texts as being positive or negative. To evaluate the performance of the SVM model, a dataset was built from tweets discussing several social issues in Saudi Arabia. These issues include changes that were implemented by the country as part of a newly established vision, known as Saudi Arabia Vision 2030. The constructed dataset was manually annotated according to the sentiment conveyed in the text. To achieve the best sentiment classification accuracy, several procedures were implemented within the proposed framework including light stemming, feature extraction (Ngrams, emoji and tweet-topic features), parameter optimisation and feature-set reduction. The experimental results revealed excellent outcomes. An accuracy of 89.83% was achieved using the proposed SVM model.

In this paper, we want to review one of the challenging problems for the opinion mining task, which is sarcasm detection. To be able to do that, many researchers tried to explore such properties in sarcasm like theories of sarcasm, syntactical properties, psycholinguistic of sarcasm, lexical feature, semantic properties, etc. Studies conducted within last 15 years have not only made progress in semantic features but have also shown increasing amounts of methods of analysis using a machine-learning approach to process data. Therefore, this paper will try to explain the most currently used methods to detect sarcasm. Lastly, we will present a result of our finding, which might help other researchers to gain a better result in the future.

Stock market reports in on-line news are widely used by amateurs to make quick investment decisions. Financial analysts often give opinions about trends of stock markets based on past and present economic event indicators. These opinions commonly appear in text form and are abundant over the Internet. It is tedious and time consuming for users to browse through such text manually let alone to understand the embedded opinions. To overcome this shortcoming, automatic trend predication methods have been proposed. Under conventional methods, reports are represented using bag of words and trend prediction is treated as a 3-way trend classification problem, i.e. trend as 'up', 'down' or 'stable'. In this paper, we propose a new pattern-based opinion mining method for market trend predication. Experiments show that (1) pattern-based classification is more effective than its word-based counterpart for feature representation; and (2) opinion mining outperforms event-based classification for trend predication. The task of opinion mining gets more difficult when the users are exposed to opinions from more than one analyst. The question becomes whose opinions should he/she trust? This lays down our second research objective, i.e. to study different opinion incorporation strategies. Intuitively, one would trust the opinion supported by the majority. However, we show that on the contrary, the user is better off trusting the most credible analyst.

This paper proposes a method that automatically creates a sentiment lexicon in a new language using a sentiment lexicon in a resource–rich language with only a bilingual dictionary. We resolve some of the difficulties in selecting appropriate senses when translating lexicon, and present a framework that sequentially applies an iterative link analysis algorithm to enhance the quality of lexicons of both the source and target languages. The experimental results have empirically shown to improve the sentiment lexicon in the source language as well as create a good quality lexicon in the new language.

Online news blogs and websites are becoming influential to any society as they accumulate the world in one place. Aside from that, online news blogs and websites have efficient strategies in grabbing readers’ attention by the headlines, that being so to recognize the sentiment orientation or polarity of the news headlines for avoiding misinterpretation against any fact. In this study, we have examined 3383 news headlines created by five different global newspapers. In the interest of distinguishing the sentiment polarity (or sentiment orientation) of news headlines, we have trained our model by seven machine learning and two deep learning algorithms. Finally, their performance was compared. Among them, Bernoulli naïve Bayes and Convolutional Neural Network (CNN) achieved higher accuracy than other machine learning and deep learning algorithms, respectively. Such a study will help the audience in determining their impression against or for any leader or governance; and will provide assistance to recognize the most indifferent newspaper or news blogs.

Recommender systems nowadays are playing an important role in the delivery of services and information to users. Sentiment analysis (also known as opinion mining) is the process of determining the attitude of textual opinions, whether they are positive, negative or neutral. Data sparsity is representing a big issue for recommender systems because of the insufficiency of user rating or absence of data about users or items. This research proposed a hybrid approach combining sentiment analysis and recommender systems to tackle the problem of data sparsity problems by predicting the rating of products from users’ reviews using text mining and NLP techniques. This research focuses especially on Arabic reviews, where the model is evaluated using Opinion Corpus for Arabic (OCA) dataset. Our system was efficient, and it showed a good accuracy of nearly 85% in predicting the rating from reviews.

Aspect-Based Sentiment Analysis (ABSA) is a challenging task in recent natural language processing research. It aims at extracting people’s sentiment polarity on a specific category. In this paper, we explore that the key phrases in sentence are highly relevant to certain aspect words which influence the final result. We propose a joint LSTM with Multi-CNN network by hierArchical aTtention (MAT) model to achieve this goal. Specifically, we design a double embedding with fully connected layer module to improve the final performance. MAT shows the effectiveness on the experiments of datasets from SemEval 2014.

This study was divided into three parts. The first part was to design and create a Chinese word segmenting custom dictionary specifically for the RFID Technology and Certification course to improve the accuracy of the word segmentation. The second part was to apply the text sentiment analysis to figure out the positive and negative emotions of students in the discussion of the course so that the teachers could quickly browse the students’ discussion, and find out any situation requiring further notice. The third part discovered that the relevance of the discussion to the course content was positively correlated with the emotions shown in the discussion.