Fangtao Li

AAAI Conference 2014 Conference Paper

Ranking Tweets by Labeled and Collaboratively Selected Pairs with Transitive Closure

• Shenghua Liu
• Xueqi Cheng
• Fangtao Li

Tweets ranking is important for information acquisition in Microblog. Due to the content sparsity and lack of labeled data, it is better to employ semi-supervised learning methods to utilize the unlabeled data. However, most of previous semi-supervised learning methods do not consider the pair conflict problem, which means that the new selected unlabeled data may have order conflict with the labeled and previously selected data. It will hurt the learning performance, if the training data contains many conflict pairs. In this paper, we propose a new collaborative semi-supervised SVM ranking model (CSR-TC), selecting unlabeled data based on a dynamically maintained transitive closure graph to avoid pair conflict. We also investigate the two views of features, intrinsic and content-relevant features, for the proposed model. Extensive experiments are conducted on TREC Microblogging corpus. The results demonstrate that our proposed method achieves significant improvement, compared to several state-of-the-art models.

AAAI Conference 2014 Conference Paper

SUIT: A Supervised User-Item Based Topic Model for Sentiment Analysis

• Fangtao Li
• Sheng Wang
• Shenghua Liu
• Ming Zhang

Probabilistic topic models have been widely used for sentiment analysis. However, most of existing topic methods only model the sentiment text, but do not consider the user, who expresses the sentiment, and the item, which the sentiment is expressed on. Since different users may use different sentiment expressions for different items, we argue that it is better to incorporate the user and item information into the topic model for sentiment analysis. In this paper, we propose a new Supervised User-Item based Topic model, called SUIT model, for sentiment analysis. It can simultaneously utilize the textual topic and latent user-item factors. Our proposed method uses the tensor outer product of text topic proportion vector, user latent factor and item latent factor to model the sentiment label generalization. Extensive experiments are conducted on two datasets: review dataset and microblog dataset. The results demonstrate the advantages of our model. It shows significant improvement compared with supervised topic models and collaborative filtering methods.

IJCAI Conference 2011 Conference Paper

Incorporating Reviewer and Product Information for Review Rating Prediction

• Fangtao Li
• Nathan Liu
• Hongwei Jin
• Kai Zhao
• Qiang Yang
• Xiaoyan Zhu

Among sentiment analysis tasks, review rating prediction is more helpful than binary (positive and negative) classification, especially when the consumers want to compare two good products. Previous work has addressed this problem by extracting various features from the review text for learning a predictor. Since the same word may have different sentiment effects when used by different reviewers on different products, we argue that it is necessary to model such reviewer and product dependent effects in order to predict review ratings more accurately. In this paper, we propose a novel learning framework to incorporate reviewer and product information into the text based learner for rating prediction. The reviewer, product and text feature are modeled as a three-dimension tensor. The tensor factorization technique is employed to reduce the sparsity and complexity problems. The experiment results demonstrate the effectiveness of our model. We achieve significant improvement as compared with the state of the art methods, especially for the reviews with unpopular products and inactive reviewers.

IJCAI Conference 2011 Conference Paper

Learning to Identify Review Spam

• Fangtao Li
• Minlie Huang
• Yi Yang
• Xiaoyan Zhu

In the past few years, sentiment analysis and opinion mining becomes a popular and important task. These studies all assume that their opinion resources are real and trustful. However, they may encounter the faked opinion or opinion spam problem. In this paper, we study this issue in the context of our product review mining system. On product review site, people may write faked reviews, called review spam, to promote their products, or defame their competitors' products. It is important to identify and filter out the review spam. Previous work only focuses on some heuristic rules, such as helpfulness voting, or rating deviation, which limits the performance of this task. In this paper, we exploit machine learning methods to identify review spam. Toward the end, we manually build a spam collection from our crawled reviews. We first analyze the effect of various features in spam identification. We also observe that the review spammer consistently writes spam. This provides us another view to identify review spam: we can identify if the author of the review is spammer. Based on this observation, we provide a two-view semi-supervised method, co-training, to exploit the large amount of unlabeled data. The experiment results show that our proposed method is effective. Our designed machine learning methods achieve significant improvements in comparison to the heuristic baselines.

AAAI Conference 2010 Conference Paper

Sentiment Analysis with Global Topics and Local Dependency

• Fangtao Li
• Minlie Huang
• Xiaoyan Zhu