How many times do we need to repeat the calculation for big networks? That’s a difficult question; for a network as large as the World Wide Web it can be many millions of iterations! The “damping factor” is quite subtle. If it’s too high then it takes ages for the numbers to settle, if it’s too low then you get repeated over-shoot, both above and below the average - the numbers just swing about the average like a pendulum and never settle down.
Also hadn’t thought about decreasing the rank value based on the spammyness of sites a page is linking into. My guess on how to do it would be determining the spammyness of individual pages based on multiple page and site factors, then some type of reverse pagerank calcuation starting with the those bad scores, then overlaying that on top of the “good” pagerank calculation as a penalty. This is another thing which would be interesting to play around with in the Nutch algorithm.
A breadcrumb is a row of internal links at the top or bottom of the page that allows visitors to quickly navigate back to a previous section or the root page. Many breadcrumbs have the most general page (usually the root page) as the first, leftmost link and list the more specific sections out to the right. We recommend using breadcrumb structured data markup28 when showing breadcrumbs.