Latent sentiment model for weakly-supervised cross-lingual sentiment classification

In this paper, we present a novel weakly-supervised method for crosslingual sentiment analysis. In specific, we propose a latent sentiment model (LSM) based on latent Dirichlet allocation where sentiment labels are considered as topics. Prior information extracted from English sentiment lexicons through machine translation are incorporated into LSM model learning, where preferences on expectations of sentiment labels of those lexicon words are expressed using generalized expectation criteria. An efficient parameter estimation procedure using variational Bayes is presented. Experimental results on the Chinese product reviews show that the weakly-supervised LSM model performs comparably to supervised classifiers such as Support vector Machines with an average of 81% accuracy achieved over a total of 5484 review documents. Moreover, starting with a generic sentiment lexicon, the LSM model is able to extract highly domainspecific polarity words from text

Positive and Negative Sentiment Words in a Blog Corpus Written in Hebrew

AbstractIn this research, given a corpus containing blog posts written in Hebrew and two seed sentiment lists, we analyze the positive and negative sentences included in the corpus, and special groups of words that are associated with the positive and negative seed words. We discovered many new negative words (around half of the top 50 words) but only one positive word. Among the top words that are associated with the positive seed words, we discovered various first-person and third-person pronouns. Intensifiers were found for both the positive and negative seed words. Most of the corpus’ sentences are neutral. For the rest, the rate of positive sentences is above 80%. The sentiment scores of the top words that are associated with the positive words are significantly higher than those of the top words that are associated with the negative words.Our conclusions are as follows. Positive sentences more “refer to” the authors themselves (first-person pronouns and related words) and are also more general, e.g., more related to other people (third-person pronouns), while negative sentences are much more concentrated on negative things and therefore contain many new negative words. Israeli bloggers tend to use intensifiers in order to emphasize or even exaggerate their sentiment opinions (both positive and negative). These bloggers not only write much more positive sentences than negative sentences, but also write much longer positive sentences than negative sentences

Exploring English lexicon knowledge for Chinese sentiment analysis

This paper presents a weakly-supervised method for Chinese sentiment analysis by incorporating lexical prior knowledge obtained from English sentiment lexicons through machine translation. A mechanism is introduced to incorporate the prior information about polarity bearing words obtained from existing sentiment lexicons into latent Dirichlet allocation (LDA) where sentiment labels are considered as topics. Experiments on Chinese product reviews on mobile phones, digital cameras, MP3 players, and monitors demonstrate the feasibility and effectiveness of the proposed approach and show that the weakly supervised LDA model performs as well as supervised classifiers such as Naive Bayes and Support vector Machines with an average of 83% accuracy achieved over a total of 5484 review documents. Moreover, the LDA model is able to extract highly domain-salient polarity words from text

SSentiaA: A Self-Supervised Sentiment Analyzer for Classification From Unlabeled Data

In recent years, supervised machine learning (ML) methods have realized remarkable performance gains for sentiment classification utilizing labeled data. However, labeled data are usually expensive to obtain, thus, not always achievable. When annotated data are unavailable, the unsupervised tools are exercised, which still lag behind the performance of supervised ML methods by a large margin. Therefore, in this work, we focus on improving the performance of sentiment classification from unlabeled data. We present a self-supervised hybrid methodology SSentiA (Self-supervised Sentiment Analyzer) that couples an ML classifier with a lexicon-based method for sentiment classification from unlabeled data. We first introduce LRSentiA (Lexical Rule-based Sentiment Analyzer), a lexicon-based method to predict the semantic orientation of a review along with the confidence score of prediction. Utilizing the confidence scores of LRSentiA, we generate highly accurate pseudo-labels for SSentiA that incorporates a supervised ML algorithm to improve the performance of sentiment classification for less polarized and complex reviews. We compare the performances of LRSentiA and SSSentA with the existing unsupervised, lexicon-based and self-supervised methods in multiple datasets. The LRSentiA performs similarly to the existing lexicon-based methods in both binary and 3-class sentiment analysis. By combining LRSentiA with an ML classifier, the hybrid approach SSentiA attains 10%–30% improvements in macro F1 score for both binary and 3-class sentiment analysis. The results suggest that in domains where annotated data are unavailable, SSentiA can significantly improve the performance of sentiment classification. Moreover, we demonstrate that using 30%–60% annotated training data, SSentiA delivers similar performances of the fully labeled training dataset

A Cross-Cultural Analysis of Sentiment in “COVID-19” Reportage of CCTV News and The New York Times

Drawing support from the artificial intelligence platform of Baidu Cloud and the natural language processing approach, this paper provides an empirically-grounded micro-analysis of Sino-American news discourses on “COVID-19” pandemic in China 2020 by using keyword wordcloud analysis on sentiment expressions, namely the discourses from the websites of CCTV News and The New York Times. The authors analyzed the media’s intended attitudes expressed with sentiment, and found that the attitude of the Chinese people and China’s media towards the epidemic was mostly positive; while New York Times was mostly negative about the epidemic, especially at the peak of the outbreak. Such a difference presents a prevalent manifestation of recognition towards the epidemic led by either government or media institutions while people face uncertainties caused by corona virus, which may further influence the public opinion and attitudes towards the epidemic, which in turn has broader social/political-interactional purposes and public cognitive construction.