Researchers from IBM, Compaq and AltaVista collaborated on this paper on the Connectivity of the web: “The study of the web as a graph is not only fascinating in its own right, but also yields valuable insight into web algorithms for crawling,

searching and community discovery, and the sociological phenomena which characterize its evolution. We report on experiments on local and

global properties of the web graph using two Altavista crawls each with over 200M pages and 1.5 billion links. Our study indicates that the

macroscopic structure of the web is considerably more intricate than suggested by earlier experiments on a smaller scale…. One can pass from any node of IN through SCC to any node of OUT.

Hanging off IN and OUT are TENDRILS containing nodes that are reachable from portions of IN, or that can

reach portions of OUT, without passage through SCC. It is possible for a TENDRIL hanging off from IN to

be hooked into a TENDRIL leading into OUT, forming a TUBE — a passage from a portion of IN to a portion

of OUT without touching SCC.” [Is that clear??]