I have been asked this question many times through my own personal blog and whilst delivering search engine marketing workshops and training. The answer is simple: often.
Many SEO professionals entertain the belief that Google shroud their activities in a cloud of mystery and that nobody knows the actual answer apart from Google employees. This isn’t actually the case. Google are reasonably open about how they manage their algorithms (without giving away any trade secrets, of course) – you just need to know where to look to get the information.
Google have several teams dedicated to continuously improving various aspects of their ranking algorithm, and this team makes regular changes to the algorithm – sometimes as often as 10 times per week!
Most of these changes are minor, and all are intended to improve the user search experience, by offering improved localised results for example, or streamlining the algorithm code to improve performance. Sometimes the changes have more significant implications for search engine optimisation and can cause websites to slip down the rankings for particular keyphrases. There’s always a good reason for the changes and the best course of action if your website has been affected is always to go back to basics: content, content, content.
