Version five of Google's Search Quality Rating Guidelines have been leaked at Scribd.com.
The rating guidelines are used by Google's human raters, who evaluate search results based on factors like relevance and usefulness. The ratings are then used by Google to check the effectiveness of algorithm tweaks.
The new version is dated March 2014, and follows previous leaked versions in 2008, 2011 and 2012 - as well as a version publicly released by Google in 2013.
Major changes to the new version include an increased emphasis on expertise, authority and trust - or 'EAT', as it's abbreviated in the guide.
The guide contains pointers on authority signifiers which are likely to be of use to SEOs. For example, it makes a distinction between high-quality medical advice and the 'everyday expertise' encountered on forums and the like.
It reads: "High-quality medical advice should come from people or organizations with appropriate medical expertise or accreditation, [...] should be written or produced in a professional style and should be edited, reviewed and updated on a regular basis."
But the guide also points out that it will value "everyday expertise" if the person creating the topic has enough relevant life experience to make a valuable contribution, with no penalties for lacking a formal education in the subject.
Google gives the example of forum users writing posts about their loved ones living with cancer, stating "this is an example of sharing personal experiences (in which they are experts), not medical advice."
News brought to you by ClickThrough – experts in SEO, PPC and conversion rate optimisation services.