anallawalla - 4:11 am on Sep 29, 2008 (gmt 0)

Tedster:

I'm pretty sure that trust calculations work like this - at least in part. Google starts with a hand picked "seed list" of trusted domains. Then trust calculations can be made that flow from those domains through their links. I've always thought of trust as one of the "query-independent" factors, like PR - that is, it's not related to any topic. So that makes another key differentiating point. Authority is related to a topic, and trust is not.

(spliced from two posts)

So the challenge is to make one's site seed-worthy. Can we assume that the Google Directory has high trust, being on the google.com domain? If so, every entry in DMOZ has inherited a good deal of trust.

However, when you look at a large corporate website and its links to a subsidiary, I think you'll find that the latter has more seed-worthiness than the DMOZ entry that was blessed by Google's trust. This suggests that trustrank distribution is similar to the ways link juice is diluted as you place more links on a page. This is asserted by the following learned paper:

Propagating Trust and Distrust to Demote Web Spam [ftp.informatik.rwth-aachen.de]

How might seed shortlists be created?

Domain ownership would play a strong part, hence whois data washed against stock exchange market cap records would easily separate the mega corporations from the IPOs. Similar comparisons from academic sources would separate the top shelf .edus from the dubious minor .edu institutions. Ditto for .gov sites.

I'd say that trust is usually a domain-wide factor, rather than being confined to a url. The papers often leave this open ended. The Link Spam Detection paper, for instance, discusses analyzing "nodes", where "nodes may be pages, hosts, or sites..."

The authors of the above paper have another view. They say:

The trust score of a page is an indication of how trustworthy the page is on the Web.

Then they introduce the concept of DisTrust and BadRank. :) I don't know if any of them have since moved to Google, so their paper may simply be a paper.