To check the quality of search results, Google uses human evaluators who manually assess results and assign ratings to pages that rank. The internal guidelines for these evaluators placed content into four categories:
A rating of Useful is assigned to pages that are very helpful for most users. Useful pages should be high quality and a good “fit” for the query. In addition, they often have some or all of the following characteristics: highly satisfying, authoritative, entertaining, and/or recent (such as breaking news on a topic).
Useful pages are usually well organized and pages you trust. They are from information sources that seem reliable.
A rating of Relevant is assigned to pages that are helpful for many or some users. Relevant pages have fewer valuable attributes than were listed for Useful pages. Relevant pages should still “fit” the query, but they might be less comprehensive, less up-to-date, come from a less authoritative source, or cover only one important aspect of the query.
A rating of Slightly Relevant is assigned to pages that are not very helpful for most users, but are somewhat related to the query. Slightly Relevant pages may be low quality and/or contain less helpful information. Slightly Relevant pages may serve a minor interpretation, have outdated information, be too specific, too broad, etc. to receive a higher rating.
Off-Topic or Useless
You will also come across pages that are so unhelpful (and possibly deceptive) that they should be rated Off-Topic or Useless. For example, you may be given a page to rate that has links and ads and no actual content. The links redirect to other pages that lead to yet other links and ads.
When nothing on the page is helpful to the user, it should be rated Off-Topic or Useless. These pages usually warrant the Spam flag
These guidelines are quite revealing about the sort of content Google is intending to rank in results. While they currently do not actually get editors to re-order results, Google’s automation techniques (such as machine learning/artificial intelligence) are intended to get close to a human interpretation.
To summarise the qualities you should be aiming for in your content:
- High quality and a good “fit” for the query
- Some of the following: highly satisfying, authoritative, entertaining, and/or recent
- Well organized
- From reliable information sources
Many of these are general in nature, but they remain good overall guidelines to consider when creating your own content. Google’s criteria do not seem unreasonable.
Note that Google allow for personal interpretation within this rating scale, referring to pages that “seem” reliable. This is likely to be affected by factors beyond the scope of copy, involving the site as a whole and how people perceive it.
Regardless, Google considers that ranking “useful” pages is a success, while ranking any pages below “relevant” in the scale is a failure that requires algorithmic correction. if your content is likely to meet Google’s definition of “useful” then it is more likely to rank in results.