Faceted blog distillation aims at retrieving the blogs that are not only relevant to a query but also exhibit an interested facet. In this paper we consider personal and official facets. Personal blogs depict various topics related to the personal experiences of bloggers while official blogs deliver contents with bloggers' commercial influences. We observe that some terms, such as nouns, usually describe the topics of posts in blogs while other terms, such as pronouns and adverbs, normally reflect the facets of posts. Thus we present a model that estimates the probabilistic distributions of topics and those of facets in posts. It leverages a classifier to separate facet terms from topical terms in the posterior inference. We also observe that the posts from a blog are likely to exhibit the same facet. So we propose another model that constrains the posts from a blog to have the same facet distributions in its generative process. Experimental results using the TREC 2009-2010 queries over the TREC Blogs08 collection show the effectiveness of both models. Our results outperform the best known results for personal and official distillation.

To explore the information seeking behaviors in microblogosphere, the microblog track at TREC 2011 introduced a real-time ad-hoc retrieval task that aims at ranking relevant tweets in reverse-chronological order. We study this problem via a two-phase approach: 1) retrieving tweets in an ad-hoc way; 2) utilizing the temporal information of tweets to enhance the retrieval effectiveness of tweets. Tweets can be categorized into two types. One type consists of short messages not containing any URL of a Web page. The other type has at least one URL of a Web page in addition to a short message. These two types of tweets have different structures. In the first phase, to address the structural difference of tweets, we propose a method to rank tweets using the divide-and-conquer strategy. Specifically, we first rank the two types of tweets separately. This produces two rankings, one for each type. Then we merge these two rankings of tweets into one ranking. In the second phase, we first categorize queries into several types by exploring the temporal distributions of their top-retrieved tweets from the first phase; then we calculate the time-related relevance scores of tweets according to the classified types of queries; finally we combine the time scores with the IR scores from the first phase to produce a ranking of tweets. Experimental results achieved by using the TREC 2011 and TREC 2012 queries over the TREC Tweets2011 collection show that: (i) our way of ranking the two types of tweets separately and then merging them together yields better retrieval effectiveness than ranking them simultaneously; (ii) our way of incorporating temporal information into the retrieval process yields further improvements, and (iii) our method compares favorably with state-of-the-art methods in retrieval effectiveness.

We investigate the problem of determining the polarity of sentiments when one or more occurrences of a negation term such as "not" appear in a sentence. The concept of the scope of a negation term is introduced. By using a parse tree and typed dependencies generated by a parser and special rules proposed by us, we provide a procedure to identify the scope of each negation term. Experimental results show that the identification of the scope of negation improves both the accuracy of sentiment analysis and the retrieval effectiveness of opinion retrieval.

Opinion retrieval is a document retrieving and ranking process. A relevant document must be relevant to the query and contain opinions toward the query. Opinion polarity classification is an extension of opinion retrieval. It classifies the retrieved document as positive, negative or mixed, according to the overall polarity of the query relevant opinions in the document. This paper (1) proposes several new techniques that help improve the effectiveness of an existing opinion retrieval system; (2) presents a novel two-stage model to solve the opinion polarity classification problem. In this model, every query relevant opinionated sentence in a document retrieved by our opinion retrieval system is classified as positive or negative respectively by a SVM classifier. Then a second classifier determines the overall opinion polarity of the document. Experimental results show that both the opinion retrieval system with the proposed opinion retrieval techniques and the polarity classification model outperformed the best reported systems respectively.

The microeconomic framework for data mining assumes that an enterprise chooses a decision maximizing the overall utility over all customers. In item selection problem, the store wants to select J item set S that maximizes the overall profit. Based on the microeconomic view, we propose a novel algorithm ItemRank to solve the problem of item selection with the consideration of cross-selling effect which has two major contributions. First, we propose customer behavior model, and demonstrate it with the data of customer-oriented business. Second, we propose the novel algorithm ItemRank which is implemented on the basis of customer behavior model. According to the cross-selling effect and the self-profit of items, ItemRank algorithm could solve the problem of item order objectively and mechanically. We conduct detailed experiments to evaluate our proposed algorithm and experiment results confirm that the new methods have an excellent ability for profit mining and the performance meets the condition which requires better quality and efficiency