With several hundred signals that are read and processed by their search algorithm, we’ve always known that Google puts a tremendous amount of time, money, and effort into making their results match their users’ needs. Now, we have an idea of how much tweaking is done: a lot.

Their “search scientists” test the changes they make in a sandbox environment to see how each change, twist, addition, and omission reacts to various searches and search types.

“Just last year we launched over 500 changes to our algorithm so by some count we change our algorithm almost every day, almost twice over,” said Google Fellow Amit Singhal.

Many of these changes happen simultaneously, so some days may have no changes, but if you average out 500 changes over a year, that’s about 1 change every 17.5 hours.

“There are almost always a set of motivating searches and these searches are not performing as well as we’d like,” said Engineering Director Scott Huffman. “Ranking engineers then come up with a hypothesis about what signal, what data could we integrate into our algorithm.”

We often take for granted how search engines come up with their results, but this video helps to break it down for us in layman’s terms.