Back in October we highlighted a thread started by Orion on the topic of Weighing the Time of a Link: Temporal Link Analysis, which discusses various algorithmic formulas that can be applied to link data in order to improve search results. The thread now gets a more practical when Bob Wyman, CEO of PubSub.com shows how his engine ranks pages. As opposed to most link algorithms, PubSub.com, DayPop.com and PopDex.com all use a form of time based link analysis to define which pages are most popular NOW.
On the PubSub LinkRanks explanation page it describes how it all works. Basically, it first collects and maps the linking data from weblogs in its index, then it assigns values for each link pointing to a page, then applies a "Link Scores for Each Domain" and finally they apply the time factor of the link data by weighing "the trailing ten days' link scores by factors of 2".
PubSub asks that I include this link that goes nowhere, http://psi.pubsub.com/20040413:linkranks:1 "to see if we can construct a conversation thread around the topic by using a common URN."