4. The method of claim 1 , wherein the first document set characterization and the second document set characterization each comprise a vector representation in which each of the first and second metadata values is a separate dimension, and wherein comparing the second document set characterization with the first document set characterization further comprises determining a distance between respective vector representations of the second document set characterization and the first document set characterization.
4. The method of claim 1 , wherein the first document set characterization and the second document set characterization each comprise a vector representation in which each of the first and second metadata values is a separate dimension, and wherein comparing the second document set characterization with the first document set characterization further comprises determining a distance between respective vector representations of the second document set characterization and the first document set characterization. 5. The method of claim 4 , further comprising: applying, by the processing device, at least one weighting factor to a given metadata value of the vector representation when determining the distance between the respective vector representations of the second document set characterization and the first document set characterization.