[Music] every day billions of people come here with questions about all kinds of things sometimes we even get questions about google search itself like how this whole thing actually works and while this is a subject entire books have been written about there's a good chance you're in the market for something a little more concise so let's say it's getting close to dinner and you want a recipe for lasagna probably seen this before but let's go a little deeper since the beginning back when the homepage looked like this google has been continuously mapping the web hundreds of billions of pages to create something called an index think of it as the giant library we look through whenever you do a search for lasagna or anything else now the word lasagna shows up a lot on the web pages about the history of lasagna articles by scientists whose last name happened to be lasagna stuff other people might be looking for but if you're hungry randomly clicking through millions of links is no fun this is where google's ranking algorithms come into play first they try to understand what you're looking for so they can be helpful even if you don't know exactly the right words to use or if your spelling is a little off then they sift through millions of possible matches in the index and automatically assemble a page that tries to put the most relevant information up top for you to choose from okay now we have some results but how did the algorithms actually decide what made it onto the first page there are hundreds of factors that go into ranking search results so let's talk about a few of them you may already know that pages containing the words you search for are more likely to end up at the top no surprise there but the location of those words like in the page's title or in an image's caption those are factors too there's a lot more to ranking than just words back when google got started we looked at how pages linked to each other to better understand what pages were about and how important and trustworthy they seemed today linking is still an important factor another factor is location where a search happens because if you happen to be in oromea italy you might be looking for information about their annual lasagna festival but if you're in omaha nebraska you probably aren't when a webpage was uploaded is an important factor too pages published more recently often have more accurate information especially in the case of a rapidly developing news story of course not every site on the web is trying to be helpful just like with robocalls on your phone or spam in your email there are a lot of sites that only exist to scam and every day scammers upload millions more of them so just because instantvirusdownload.net lists the words lasagna recipe 400 times that doesn't mean it's going to help you make dinner we spend a lot of time trying to stay one step ahead of tricks like these making sure our algorithms can recognize scam sites and flag them before they make it to your search results page so let's review billions of times a day whenever someone searches for lasagna or resume writing tips or how to swaddle a baby or anything else google software locates all the potentially relevant results on the web removes all the spam and ranks them based on hundreds of factors like keywords links location and freshness okay good time to take a breath this last part is about how we make changes to search and it's important since 1998 when google went online people seem to have found our results pretty helpful but the web is always changing and people are always searching for new things in fact one in every seven searches is for something that's never been typed into the search box before by anyone ever so we're always working in updates to search thousands every year which brings up a big question how do we decide whether a change is making search more helpful well one of the ways we evaluate potential updates to search is by asking people like you every day thousands of search quality raters look at samples of search results side by side then give feedback about the relevance and reliability of the information to make sure those evaluations are consistent the raters follow a list of search quality evaluator guidelines think of them as our publicly available guide to what makes a good result good oh and one last thing to remember we use responses from raiders to evaluate changes but they don't directly impact how search results are ranked so there you have it every time you click search our algorithms are analyzing the meaning of the words in your search matching them to the content on the web understanding what content is most likely to be helpful and reliable and then automatically putting it all together in a neatly organized page designed to get you the info you need all in oh 0.81 seconds wow anyone else ready for dinner interested in learning more we've got a whole website dedicated to how search works just click right here want to read the search quality raider guidelines for yourself click right here [Music] you