1. A system for providing reference documents as a suggestion for classifying electronically stored information using nearest neighbor, comprising: a clustering module to provide a set of uncoded electronically stored information items and a different set of reference electronically stored information items that are each classified with a code; a similarity module to compare at least one of the uncoded electronically stored information items from the set with the set of reference electronically stored information items and to identify one or more of the reference electronically stored information items that are similar to the at least one uncoded electronically stored information item; a processing module to process the classification codes associated with the similar reference electronically stored information items, comprising: a type module to determine a number of different types of the classification codes associated with the similar reference electronically stored information items; a presence module to determine one or more of a presence and absence of the similar reference electronically stored information items with each type of the different classification codes; and a quantity module to determine for each type of the classification codes a quantity of the similar reference electronically stored information items; a suggestion module to display a visual classification suggestion based on at least one of the presence and the absence and the quantity and the number of the types via a display of the at least one uncoded electronically stored information item and the similar reference electronically stored information items; a receipt module to receive a classification code of one of the types for the at least one uncoded electronically stored information item from a human reviewer based on the suggestion; and a processor to execute the modules.
2. A system according to claim 1 , further comprising: a reference set module to generate the set of reference electronically stored information items, comprising at least one of: a comparison module to obtain a set of electronically stored information items, to identify one or more electronically stored information items that are dissimilar from each other electronically stored information item, and to assign a classification code to each of the dissimilar electronically stored information items, as the reference electronically stored information items; and a reference clustering module to group electronically stored information items for a document review project into one or more clusters, to select one or more of the electronically stored information items in at least one cluster, and to assign a classification code to each of the selected electronically stored information items, as the reference electronically stored information items.