Google Patent Application

1. Google scores a document using history data which includes:

2. the inception date of the document.

3. on a difference between the ages of the documents and the average age.

4. on an elapsed time measured from the inception date corresponding to the document.

5. a date when a search engine first discovers a link to the document, and a date when the document includes at least a predetermined number of pages.

6. the frequency that the content changes over time.

7. comparison of a rate of change in a current time period with a rate of change in a previous time period.

8. the frequency at which and the amount by which the content of the document changes over time.

9. a ratio of a number of new pages associated with the document versus a total number of pages associated with the document, and a percentage of the content of the document that has changed during a time period.
10. weighting different portions of the content of the document differently based on a perceived importance of the portions, and determining the amount by which the content of the document changes as a function of the differently weighted portions of the content.

11. determining a date on which the content of each of the documents last changed, determining an average date of change based on the determined dates on which the contents of the documents last changed, and scoring the documents based, at least in part, on a difference between the dates on which the contents of the documents last changed and the average date of change.

12. on the amount by which the content of the document changes over time.

13. on at least one of a number of new pages associated with the document within a time period, a ratio of a number of new pages associated with the document versus a total number of pages associated with the document, and a percentage of the content of the document that has changed during a time period.

14. weighting different portions of the content of the document differently based on a perceived importance of the portions.

15. how often the document is selected when the document is included in a set of search results

17. whether the document is associated with the search terms.

18. whether the document is associated with queries that lead to results that change over time.

19. whether the document is stale.

20. whether stale documents are considered favorable for the search query when the document is determined to be stale.

21. determining whether stale documents are considered favorable for the search query is based, at least in part, on how often stale documents were selected over recent documents over time for the search query.

22. behavior of links associated with the document.

23. appearance and disappearance of one or more links pointing to the document.

24. rate at which the one or more links disappear over time, and a number of the one or more links that disappear during a time period.

25. how many links associated with the document appear or disappear during a time period, and whether there is a trend toward appearance of new links associated with the document versus disappearance of existing links associated with the document.

26. assigning weights to the links based on the determined freshness

28. how much a document containing the link is trusted, how authoritative a document containing the link is, and a freshness of a document containing the link.

29. on the age distribution associated with the links.

30. on the change in anchor text associated with a link to the document.

31. whether the content of the document changes such that the content differs from the anchor text associated with one or more links to the document.

32. freshness of anchor text associated with one or more links to the document.

34. on the characteristics of traffic associated with the document.

36. user behavior associated with the document.

37. number of times that the document is selected within a set of search results and an amount of time that one or more users spend accessing the document.

38. analyzing domain-related information corresponding to a domain associated with the document over time.

39. the domain associated with the document is legitimate.

40. expiration date of the domain, a domain name server record associated with the domain, and a name server associated with the domain.

41. the prior ranking history of the document.

42. the quantity or rate that the document moves in the rankings.

43. a rate at which the document is selected as a search result over time, seasonality, burstiness, and changes in scores over time for a URL-query pair.

44. monitoring a rank of the document over time for spikes in the rank.

45. user maintained or generated data indicates that the document is of interest to a user.

46. the user maintained or generated data relates to at least one of favorites lists, bookmarks, temp files, and cache files associated with one or a plurality of users.

47. a rate at which the document is added to or removed from the user maintained or generated data, and whether the document is added to, deleted from, or accessed through the user maintained or generated data.

48. the growth profile of anchor text associated with one or more links to the document.

49. on the number of independent peers.

50. performing topic extraction relating to the document, monitoring a topic of the document for changes over time.

51. a relevancy score for the document based on how relevant the document is to the search query.

52. the plurality of types of history data.

53. one or more types of history data.

54. ranking the linked document based on a decaying function of the age of the linkage data.

57. linkage data includes a rank based, at least in part, on links and anchor text provided by one or more linking documents and related to the linked document.

58. the longevity of the linkage data and the indication of content update for the linking document.

59. penalizing the ranking if the longevity indicates a short life for the linkage data and boosting the ranking if the longevity indicates a long life for the linkage data.

60. penalizing the ranking if at least a portion of content from the linking document is considered stale over a period of time and boosting the ranking if the portion of content from the linking document is considered updated over the period of time.

61. determining an indication of link churn for a linking document providing the linkage data; and based on the link churn, adjusting the ranking of the linked document.

63. penalizing the ranking if the link churn is above a threshold.