“…Nevertheless, the TreeMaps have also two drawbacks: on the one hand, for the novice user, the hierarchical structure is quite hard to perceive and it is very difficult to distinguish among the different levels of the dendrogram; and on the other hand, the relative position of the blocks (i.e. the clusters) on the screen is not necessarily very intuitive and requires some practices, even if some studies, like those about the Voronoi TreeMaps [3] and the Jigsaw maps [36], are interesting from this point of view, since they propose a more natural topology of the clusters. While the TreeMaps offers an unmatchable density of information, they are not well adapted to our problem.…”