Color of a point on the map NZhole corresponds to Popularity Rank value of a web-page and map's points are ordered from left to right and from top to bottom in ascending order of hops count (the number of "mouse clicks" from a start page). The pages exactly specified in the search engine config file, receive value of hops equal to 0, the pages proposed to indexing via web-form or picked-up from one of internet directories, receive value of hops equal to 1. All other pages at the insert into the base of search engine receive value of hops on 1 more, than the page where the link to this page has been found out. In such sorting the smoothed map looks like this:
If now to order all over again on number of inbound links of page, and then on hops number, the map will look so:
Ordering on number of outbound links, and then on number of hops:
Ordering all over again on a difference between the number of inbound and the number of outbound links:
Ordering on a difference between the number of outbound and the number of inbound links:
On these maps it is possible to notice, that the rating of popularity (Popularity Rank) usually higher for pages with the number of inbound links is relatively high, but also higher than the number of outbound links. And conversely, if the page has more outbound links than inbound, her popularity rating will be usually below.
Thus, it's looks like the PopRank used in DataparkSearch is more robust against linking spam than Google's PageRank is.
This article in Russian: Немного когнитивности.