The advent of Web 2.0 has led to an increase in the amount of sentimental content available in the Web. Such content is often found in social media web sites in the form of movie or product reviews, user comments, testimonials, messages in discussion forums etc. Timely discovery of the sentimental or opinionated web content has a number of advantages, the most important of all being monetization. Understanding of the sentiments of human masses towards different entities and products enables better services for contextual advertisements, recommendation systems and analysis of market trends. The focus of our project is sentiment focussed web crawling framework to facilitate the quick discovery of sentimental contents of movie reviews and hotel reviews and analysis of the same. We use statistical methods to capture elements of subjective style and the sentence polarity. The paper elaborately discusses two supervised machine learning algorithms: K-Nearest Neighbour(K-NN) and Naive Bayes and compares their overall accuracy, precisions as well as recall values. It was seen that in case of movie reviews Naive Bayes gave far better results than K-NN but for hotel reviews these algorithms gave lesser, almost same accuracies.

本文介绍了一种利用情感分析的Web爬取框架，以便快速发现电影评论和酒店评论的情感内容及分析，并详细讨论了两种监督式机器学习算法：K-最近邻算法（K-NN）和朴素贝叶斯算法，并比较了它们的总体准确度、精确度和召回率。研究发现，在电影评论方面，朴素贝叶斯算法比K-NN算法效果好得多，但在酒店评论方面这些算法效果相对较差并且几乎相同。

使用朴素贝叶斯和K-NN分类器对评论数据集进行情感分析