"the ranking of Google search results" 是 google 的命脉，因此很少能看到官方的说明。原因倒也无可厚非："competition and abuse"，这两件事情确实哪一个都不容忽视！
不过近日，google 负责搜索质量的 VP， Udi Manber，透露了一些有意思的资料，"Introduction to Google Search Quality"。对 search 感兴趣的千万不要错过！我列举一下我感兴趣的。
- more than one thousand programmer/scientist years have gone directly into their development (that is to say "the ranking algorithms").
- divided into some teams
- The heart of the group is the team that works on core ranking
- Another team in our group is responsible for evaluating how well we're doing
- Another team is dedicated to new features and new user interfaces
- There is a whole team that concentrates on fighting webspam and other types of abuse
- There are other teams devoted to particular projects
- PageRank [1] is still in use today, but it is now a part of a much larger system. … made significant changes to the PageRank algorithm in January, 2008.
- some other parts
- language models (the ability to handle phrases, synonyms, diacritics, spelling mistakes, and so on)
- query models (it's not just the language, it's how people use it today)
- time models (some queries are best answered with a 30-minutes old page, and some are better answered with a page that stood the test of time)
- personalized models (not all people want the same thing).
- Google conducts evaluations typically in three manners, (1) automated evaluations every minute, (2) periodic evaluations of our overall quality and (3) evaluations of specific algorithmic improvements.
- In 2007, … more than 450 new improvements, about 9 per week on the average.
- .. work on projects where the sole purpose is to simplify the algorithms. Simple is good.
Udi Manber 是我最景仰的几位科学家之一。"Chief Algorithms Officer"这个职位，就是 Amazon 专门为表彰他的贡献而首创出来的。
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