Google's official blog has announced a notable change in the ranking algorithms being used by the search engine, which are initially being introduced on Google.com but will eventually affect all versions of Google search.

Google says that the latest change will impact 11.8% of their search queries and it is designed to reduce rankings for low-quality sites. These are sites which Google considers are low-value for users, such as those that copy content from other websites or sites that are just 'not very useful'. At the same time, Google says it will provide better rankings for high-quality sites, namely sites with original content and information such as research, in-depth reports, 'thoughtful analysis and so on'.

This change is in response to growing criticism in recent months about the quality of the search results being presented by Google and the growth of 'content spam' to try to manipulate ranking positions. It remains to be seen how noticeable these changes are for most searchers and websites that generate visitor traffic from Google. However, this change is a restatement of Google's core principles and an adjustment to reflect what they hope are the best results for users.