豆知识 2010-05-16&05-22 Google三大核心业务之一：搜

 Hi. My name is Matt Cutts. I’m an engineer in the quality group of Google, and I’d like to talk today about what happens when you do a web search. 

 

 

The first thing to understand is that when you do a Google search, you aren’t actually searching the web, you’re searching Google’s index of the web, or at least as much of it as we can find. We do this with software programs called spiders. Spiders start by fetching a few webpages, then they follow the links on those pages and fetch the pages they point to and follow all the links on those pages and fetch the pages they link to and so on until we index a pretty big chunk¹ of the web. Many billions of pages stored across thousands of machines. 

 

 

Now, suppose I want to know how fast a cheetah² can run. I type in my search, say "cheetah running speed" and hit return. Our software searches our index to find every page that includes those search terms. In this case, there are hundreds of thousands of possible results. How does Google decide which few documents I really want? By asking questions, more than two hundred of them, like: How many times does this page contain your keywords? Do the words appear in the title, in the URL, directly adjacent? Does the page include synonyms³ for those words? Is this page from a quality website or is a low quality, even spamming? What is this page’s page rank? That’s a formula invented by our founders⁴ Larry Page and Sergey Brin that rates a webpage’s importance by looking at how many outside links point to it, and how important those links are. Finally we combine all those factors together to produce each page’s overall score, and send you back your search results about half a second after you submit your search. At Google, we take our commitment to delivering useful and impartial⁵ search results very seriously. We don’t ever accept payment to add a site to our index, update more of them, or improve its ranking. 

 

 

Let’s take a look at my search results.

 

 

Each entry includes a title, a URL and a snippet of the text to help me decide whether this page is what I’m looking for. I also see links to similar pages, Google’s most recent stored version of that page, and related searches that I might want to try next. And sometimes along the right and at the top, I’ll see ads. We take our advertising⁶ business very seriously as well. 

 

 

Both our commitment to deliver the best possible audience for advertisers, and to strive to only show ads that you really want to see. We’re very careful to distinguish your ads from regular search results. And we won't show you any ads at all if we can’t find any that we think will help you find information you're looking for, which in this case, the cheetah's top running speed is more than sixty miles an hour. 

 

 

Thanks for watching. I hope this made Google a little bit more understandable.

1 chunk   

n.厚片，大块，相当大的部分（数量）

参考例句：

• They had to be careful of floating chunks of ice.他们必须当心大块浮冰。
• The company owns a chunk of farmland near Gatwick Airport.该公司拥有盖特威克机场周边的大片农田。

2 cheetah   

n.(动物)猎豹

参考例句：

• The cheetah is generally credited as the world's fastest animal.猎豹被公认是世界上跑得最快的动物。
• The distribution of the cheetah ranges from Africa to Central Asia.印度豹的足迹遍及从非洲到中亚的广大地区。

3 synonyms   

同义词( synonym的名词复数 )

参考例句：

• If you want to grasp English, you must carefully discriminate synonyms. 如果你想掌握好英语，你必须仔细区分同义词。
• Study the idioms and synonyms l wrote down before your test. 学考试前我给你写的习惯用语和同义字。

4 founders   

n.创始人( founder的名词复数 )

参考例句：

• He was one of the founders of the university's medical faculty. 他是该大学医学院的创建人之一。 来自辞典例句
• The founders of our religion made this a cornerstone of morality. 我们宗教的创始人把这看作是道德的基石。 来自辞典例句

5 impartial   

adj.(in,to)公正的，无偏见的

参考例句：

• He gave an impartial view of the state of affairs in Ireland.他对爱尔兰的事态发表了公正的看法。
• Careers officers offer impartial advice to all pupils.就业指导员向所有学生提供公正无私的建议。

6 advertising   

n.广告业；广告活动 a.广告的；广告业务的

参考例句：

• Can you give me any advice on getting into advertising? 你能指点我如何涉足广告业吗?
• The advertising campaign is aimed primarily at young people. 这个广告宣传运动主要是针对年轻人的。