11. A non-transitory computer-readable medium having instructions encoded thereon, which, when executed by a processor, cause the processor to perform operations comprising: identifying, with one or more processors, a set T of query terms; selecting, with the one or more processors, candidate documents D that each satisfy one or more of the terms of the set T; selecting, from the candidate documents D, a set S of quantity k of the candidate documents D based on a weighted-coverage function ƒ for the set T of terms; pairing each document in the set S with another document in the set S based on a distance between the paired documents; generating, with the one or more processors, a set C of clusters from the paired documents, each cluster in the set C being associated with one or more topics of the query terms; selecting, with the one or more processors, from the set S, a set V of quantity p documents, for one or more clusters of the set C, based on a diversity function, wherein the diversity function is expressed as (Σ 1≦i≦k, 1≦j≦p Σ 1≦i′≦k′, 1≦j′≦p GJD(D i j , D i′ j′ )); and providing for presentation the set V of documents as representative documents that cover one or more topics associated with the one or more clusters.
11. A non-transitory computer-readable medium having instructions encoded thereon, which, when executed by a processor, cause the processor to perform operations comprising: identifying, with one or more processors, a set T of query terms; selecting, with the one or more processors, candidate documents D that each satisfy one or more of the terms of the set T; selecting, from the candidate documents D, a set S of quantity k of the candidate documents D based on a weighted-coverage function ƒ for the set T of terms; pairing each document in the set S with another document in the set S based on a distance between the paired documents; generating, with the one or more processors, a set C of clusters from the paired documents, each cluster in the set C being associated with one or more topics of the query terms; selecting, with the one or more processors, from the set S, a set V of quantity p documents, for one or more clusters of the set C, based on a diversity function, wherein the diversity function is expressed as (Σ 1≦i≦k, 1≦j≦p Σ 1≦i′≦k′, 1≦j′≦p GJD(D i j , D i′ j′ )); and providing for presentation the set V of documents as representative documents that cover one or more topics associated with the one or more clusters. 12. The non-transitory computer-readable medium of claim 11 , wherein each document in the set S is paired with another, closest document in the set S.