Mining Words and Targets Using Alignment Model

Opinion target is defined as the object about which user expresses their opinions, typically as nouns or noun phrases. Opinion words are the words that are used to express user’s opinions. Constructing an opinion words lexicon is also important because the lexicon is beneficial for identifying opinion expressions. Opinion mining is also called sentiment analysis, involves building a system to collect and categorize opinions about a product. Existing system uses Sentence-level extraction and corpus –level extraction. Sentence level extraction is the task of opinion target/word extraction is to identify the opinion target mentions or opinion expressions in sentences. These tasks are usually regarded as sequence-labeling problems. Sequence labeling models are used to build the extractor, such HMM. Corpus-level extraction did not identify the opinion target/word mentions in sentences, but aimed to extract a list of opinion targets or generate a sentiment word lexicon from texts. To overcome these problems by using alignment models.