Patent Document ID: 8392175
Application ID: 12785105

Base Claim:
1. A method of extracting phrases from a corpus of documents, the method comprising: generating, by a processor, a set of candidate phrases from the documents in the corpus, wherein each candidate phrase corresponds to a group of two or more words that occur consecutively in at least one of the documents in the corpus, each candidate phrase having an occurrence count associated therewith, wherein generating the set of candidate phrases includes: extracting a group of consecutive words from one of the documents in the corpus; determining whether the group of consecutive words appears as one of the candidate phrases in a first list of candidate phrases; in the event that the group of consecutive words appears as one of the candidate phrases in the first list, incrementing an occurrence count associated with the one of the candidate phrases; and in the event that the group of consecutive words does not appear as one of the candidate phrases in the first list: determining whether the group of consecutive words appears as one of the candidate phrases in a second list of candidate phrases, wherein each candidate phrase in the second list is associated with an occurrence count equal to 1; in the event that the group of consecutive words appears as one of the candidate phrases in the second list, promoting the one of the candidate phrases to the first list; and in the event that the group of consecutive words does not appear as one of the candidate phrases in the second list, adding the group of consecutive words as a new candidate phrase to the second list; computing, by the processor, a statistical metric for each candidate phrase based at least in part on the occurrence count, wherein the statistical metric indicates a likelihood of the words within the candidate phrase occurring consecutively by chance; and selecting, by the processor, a plurality of the candidate phrases as meaningful phrases, the selection being based on the statistical metric.

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Claim 5:
5. The method of claim 1 further comprising: constructing, by the processor, a document vector for each of a plurality of documents from the corpus, the document vector including a first plurality of components corresponding to words and a second plurality of components corresponding to at least some of the meaningful phrases; and forming, by the processor, a plurality of clusters of documents based at least in part on the document vectors.