Origin of "Bad" Hub
The experiment indicates that high dimensionality and skewness of are not sufficient to induce "bad" hubs. Instead, based on the former fact, we can argue that there are two, mostly independent, forces at work:
- violation of the cluster assumption
- high intrinsic dimensionality
"Bad" hubs originate from putting the two together; that is, the consequences of violating the cluster assumption can be more severe in high dimensions than in low dimensions, not in terms of the total amount of "bad" k-occurrences, but in terms of their distribution, since strong regular hubs are now more prone to "pick up" bad k-occurrences than non-hub points.