Google analyzes the text of outside links on pages Y1..Yn to page X in calculating the keyword relevance for page X. But does PageRank of Y directly affect the weighting of terms in its link text to X, or does the cumulative PageRank of page X independently boost the ranking of page X for all terms?
For example, lets say Yahoo has a link to a Yak page and it's the only one on the Web using the words "Yawning and Yakking". Another 50 PR 3 pages link to the same page using the word "Yolanda's Yak". Will the Yak page rank higher in a search for "Yawning and Yakking", due to Yahoo's PageRank, or for "Yolanda's Yak" because 50 pages use that link text and the Yak page has high cumulative PR for all terms?
Also, is link text within the domain or network IP range rated differently from link text found on pages outside the domain & network?
I'm thinking its better to get lots of keyword-targeted links on low ranking pages, and I think the domain and IP range are ignored in figuring keyword relevance.
Good questions, and ones I've been wanting to know the answers to for a long time. I doubt that we'll ever really know but I can tell you that in my experience the IP range is NOT important - although I used to worry about making sure my links were from other IPs which were significantly different.