
66 ◾ Accel erating Disc over y
which relies on three category centroids to dene the plane of most inter-
est and to project the documents as points on this plane (by nding the
intersection with a normal line drawn from point to plane). e selection
of which categories to display in addition to the selected category is based
on nding the categories with the nearest centroid distance to the selected
category. e documents displayed in such a plot are colored according to
category membership. e centroid of the category is also displayed. e
resultant plot is a valuable way to discover relationships between neigh-
boring concepts in a ta