UIC at TREC 2008 Blog Track

Our opinion retrieval system has four steps. In the first step, documents which are deemed relevant by the system with respect to the query are retrieved, without taking into consideration whether the documents are opinionative or not. In the second step, the abbreviations of query concepts in documents are recognized. This helps in identifying whether an opinion is in the vicinity of a query concept (which can be an abbreviation) in a document. The third step of opinion identification is designed for recognizing query-relevant opinions within the documents. In the forth step, for each query, all retrieved opinionated documents are ranked by various methods which take into account IR scores, opinion scores and the number of concepts in query. For the polarity subtask, the opinionative documents are classified into positive, negative and mixed types by two classifiers. Since TREC 2008 does not require mixed documents, all documents which are deemed mixed by our system are discarded.