11. A computer-implemented method for populating clusters of documents, comprising: placing a set of clusters in a display in relation to a common origin; selecting one of a plurality of unclustered documents in the display and determining an angle θ of the document from the common origin; computing for each cluster, an angle σ of the cluster relative to the common origin; determining a difference between the document angle θ and one such cluster angle σ; applying a predetermined variance to the difference; and placing the document into the cluster when the difference is less than the variance.
12. A method according to claim 11 , further comprising: forming the clusters based on themes.