I. Introduction
Sentiment analysis tasks automatically detect users’ sentiment polarity (positive or negative) on a given target (e.g., products, services, issues, and events), which has been well studied by many works for individual review analysis [1], [2], [3]. Instead of individual review sentiments, many sentiment classification applications demand the attention of overall sentiment polarities on a set of reviews corresponding to a target, such as market research for products, brand positioning, and open-answer classification for social sciences [4]. Sentiment Quantification aims to detect the overall sentiment polarity of users from a set of reviews corresponding to a specific target [5], [6].