What is Google AuthorRank?
What Signals Will Factor Into AuthorRank?
Google considers 200+ ranking factors when determining where our sites rank in organic search.
The average PageRank of an author’s content.
The average number of +1s and Google+ shares the author’s content receives.
The number of Google+ circles an author is in.
Reciprocal connections to other high AuthorRank authors.
The number and authority of sites an author’s content has been published to.
The engagement level of an author’s native Google+ content (i.e., posts to Google+).
The level of on-site engagement for an author’s content
Outside authority indicators (e.g., the presence of a Wikipedia page).
YouTube subscribers and/or engagement on authored videos (speculation: multiple-attribution author markup for YouTube videos coming soon).
Any number of importance/authority metrics on social networks that Google deems trustworthy
Real world authority indicators like published works on Google Books or Google Scholar.
Via WordPress SEO & Social Media, Neil Ferree