On the day of Google's 15th birthday, Google released its new "Hummingbird" search algorithm, this is the first time that Google changes its search algorithm since 2010 after the Caffeine algorithm. It will affect 90% of search results, according to Amit Singhal, Lead of Google Search.Some may be curious about how Google measures the improvement of a new search algorithm. There are many factors need to be considered, for example, accuracy, relevance, search depth etc. According to Amit Singhal, they have the entire web in a sandbox that only their engineers can see, and their engineers can tak...