In a bid to shed light on Google´s search algorithm and how it affects rankings, the search engine´s head of spam, Matt Cutts, has spoken about the dynamics of search result rankings and why they change over time in a video published on YouTube.
Cutt´s explanations shed light on why new pieces of content tend to be placed in higher positions, such as top 30 to 50 results for targeted keywords, but in days or weeks they can drop further down the list. Cutts said that when a new item of content appears Google has very limited information about it. Without knowing the original source of information and having restricted data about its relevance to users, the search engine algorithm makes its best guess and ranks the item of content relatively high. Over time, the search engine gathers more information on this content and within hours, days or weeks it can be ranked against other results more objectively.
Google´s search algorithm is not static, Cutts went on, because people from different countries or even cities want different information when they enter a query. Just as results vary from user to user, so do rankings over time because content changes and links are altered on the Internet all the time.
Variations in ranking are very common but the degree to which they change depends on the query. Certain queries require fresh content, whereas others call for more settled, proven content, Cutts concluded.
The full video can be viewed at http://www.youtube.com/watch?v=BzfK6isC7CA.