Authority and Trustrank
Yesterday I discovered the original Trustrank paper from 2004. Trustrank is a term coined by some Yahoo engineers to describe a new algorithm to determine relevant search results.
The new thing about Trustrank is that it does not solely count links like PageRank it's based on but it also relies on authority.
Authority is measured by the proximity to a group of seed sites that are deemed to be authority sites.
It sounds complicated but in the end it's simple: Let's say Adobe.com is an authority site. A site x linked by Adobe.com is thus more authoritative than a site y that has been linked by site x or a site z that hasn't been linked by any of those, Adobe, x or y. In this example y still inherits some authority from Adobe.com - Adobe trusts site x and site x trusts site y so that site y still must have some value.
Most people in the SEO industry assume that not only Yahoo employs Trustrank but Google as well without using the term maybe but inherently it's the same concept.
How do you become an authority site? What are the actual factors of an authority site?
- links from the good seed sites or sites linked by such seed sites
- domain age, the older the better
- domain history, has a domain changed owners, topics, been used or misued for low quality content
- branding, does the domain have a brand and how often does that brand or domain name get mentioned
- cluster, a site belonging to a cluster of similar sites dealing with the same topic or is it an island
- hub, does the site link out to many other sites and is resource rich
- social media saturation, being prominent on social sites with votes by power accounts
- frequency, how often does a site offer new content
- integrity, broken links and images, other errors, high load times
- bad neighborhoods, does a site contain links to low quality sites or gets linked by such sites
- filters, does a site deal with topics like xxx, gambling, generic medicines
These are some of the aspects that are most likely determining your authority on the Web both from the user and a search engine perspective.
Most of these qualities can be acquired by SEO 2.0 others require good old SEO (1.0) best practices.
For instance you can get links from seed sites by applying the SEO 2.0 way of establishing relationships with others in your industry and beyond. On the other hand broken links require good old SEO 1.0 ways of checking them. Some of the above is not even considered SEO by many, for instance checking uptimes and security measures.
So you see there is much to do to become an authority site and to please an algorithm that employs some kind of Trustrank. I'm not the scientific SEO guy so I might be not very accurate in this list above but these are commom sense aspects of a functioning website that won't hurt your site even in case the SEO benefits were marginal.