6. The method of claim 1 , further comprising: determining whether one or more of the plurality of clusters include more than one of the plurality of term groups; selecting, based on determining that one or more of the plurality of clusters include more than one of the plurality of term groups, at least one cluster, of the plurality of clusters, occurring greater than a threshold amount; and determining a similarity metric of the received document and another document that corresponds to the at least one cluster occurring greater than the threshold amount.
1. A method performed by one or more server devices, the method comprising: receiving, using one or more processors associated with the one or more server devices, a document; selecting, using one or more processors associated with the one or more server devices, terms from the received document to form a plurality of term groups for the received document, each term group, of the plurality of term groups, being associated with an indication that a first term, of the term group, occurs before a second term, of the term group, within the received document; identifying, using one or more processors associated with the one or more server devices and from an inverted index of term groups, one or more clusters of a plurality of clusters, each cluster, of the one or more identified clusters, comprising a set of term groups for a respective other document, each respective term group, of the set of term groups, being associated with an indication that a first term, of the respective term group, occurs before a second term, of the respective term group, within the respective other document; determining, using one or more processors associated with the one or more server devices, measures of similarity between the plurality of term groups for the received document and the set of term groups for each of the one or more identified clusters; and determining, using one or more processors associated with the one or more server devices and based on the determined measures of similarity, that the received document is similar to the respective other document.