1. A computer implemented method of identifying a phrase weighting of a sequence of words as a function of the position of words present in the sequence of words, comprising: identifying a sequence of words; determining, utilizing one or more processors, a centrality value for each of a plurality of identified words in the sequence of words, the centrality value for each of the identified words based on a co-occurrence consistency with other of the identified words in their respective relative positions in the sequence of words; and determining, utilizing one or more processors, a phrase weighting of the sequence of words based on the determined centrality value for each of the identified words, wherein the phrase weighting provides an indication of the likelihood that the sequence of words is a phrase.
5. The method of claim 1 , further comprising identifying the sequence of words for indexing as a phrase when the phrase weighting is greater than a threshold phrase weighting.