3. A system according to claim 1 , further comprising: a spine module to determine a similarity between the clusters and to organize the clusters along one or more spines based on the similarity, each of the spines comprising a vector; a spine vector module to identify cluster centers for all of the clusters along one of the spines and to generate a score vector for the spine based on the cluster centers; a reference document vector module to generate score vectors for the reference documents based on content of the reference documents; a comparison module to compare the score vector for the spine to the score vectors for the reference documents and to identify those of the reference documents that are similar to the spine based on the comparison of the spine score vector to the score vectors of the reference documents; a spine classification module to visually represent the classification codes of each of the reference documents similar to the spine as a suggestion for assigning one of the classification codes to the spine.
3. A system according to claim 1 , further comprising: a spine module to determine a similarity between the clusters and to organize the clusters along one or more spines based on the similarity, each of the spines comprising a vector; a spine vector module to identify cluster centers for all of the clusters along one of the spines and to generate a score vector for the spine based on the cluster centers; a reference document vector module to generate score vectors for the reference documents based on content of the reference documents; a comparison module to compare the score vector for the spine to the score vectors for the reference documents and to identify those of the reference documents that are similar to the spine based on the comparison of the spine score vector to the score vectors of the reference documents; a spine classification module to visually represent the classification codes of each of the reference documents similar to the spine as a suggestion for assigning one of the classification codes to the spine. 4. A system according to claim 3 , further comprising at least one of: a spine neighborhood module to generate a neighborhood comprising a predetermined number of the reference concepts most similar to the spine based on the comparison of the spine score vector to the score vectors of the reference documents and to assigning one of the classification codes to the spine based on the classification codes of the reference documents in the neighborhood; and a cluster neighborhood module to generate a neighborhood for the cluster comprising a predetermined number of the reference concepts most similar to the cluster based on the comparison of the cluster center to the reference documents and to assign one of the classification codes to the cluster based on the classification codes of the reference documents in the neighborhood for the cluster.