Systems and methods for determining document freshness

• US 20050144193A1
• Filed: 06/30/2004
• Published: 06/30/2005
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Henzinger, Monika
• Granted Patent: US 7,797,316 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques

Abstract

A system determines a freshness of a first document. The system determines whether a freshness attribute is associated with the first document. The system identifies, based on the determination, a set of second documents that each contain a link to the first document. The system assigns a freshness score to the first document based on a freshness attribute associated with each document of the set of second documents or the freshness attribute associated with the first document.

Claims

1. A method of determining the freshness of a first document, comprising:

identifying a set of second documents that each contains a link to the first document;

determining a freshness attribute associated with each document of the set of second documents; and

assigning a freshness score to the first document based on the freshness attribute associated with each document of the set of second documents.

2. The method of claim 1, wherein the freshness attribute indicates when each document was last modified or updated.

3. The method of claim 2, wherein the freshness attribute comprises a HTTP “

last-modified-since”

attribute.

4. The method of claim 1, further comprising:

identifying times at which each of the links to the first document existed;

wherein assigning the freshness score to the first document is further based on the identified times.

5. The method of claim 1, further comprising:

executing a search of a corpus of documents to return results comprising a plurality of documents, wherein the plurality of documents include the first document.

6. The method of claim 5, further comprising:

using the assigned freshness score as one basis for ranking the first document among the plurality of documents returned as the results of the executed search.

7. The method of claim 1, wherein assigning a freshness score to the first document further comprises:

assigning a low freshness score to the first document if more documents of the set of second documents have associated freshness attributes that indicate that the corresponding documents are not fresh.

8. The method of claim 1, wherein assigning a freshness score to the first document further comprises:

assigning a high freshness score to the first document if more documents of the set of second documents have associated freshness attributes that indicate that the corresponding documents are fresh.

9. A system, comprising:

a search engine to;

perform a search of a corpus of documents to return a plurality of documents, wherein the plurality of documents include a first document,

identify a set of second documents that each contains a link to the first document,

determine a freshness attribute associated with each document of the set of second documents,

assign a freshness score to the first document based on the freshness attribute associated with each document of the set of second documents, and

rank the first document among the plurality of documents based, at least in part, on the assigned freshness score.

10. A computer-readable medium containing instructions for controlling at least one processor to perform a method of determining the freshness of a first document, the method comprising:

identifying a set of second documents that each contain a link to the first document; and

assigning a freshness score to the first document based on a freshness attribute associated with each document of the set of second documents.

11. A method of determining the freshness of a first document, comprising:

determining whether a freshness attribute is associated with the first document;

identifying, based on the determination, a set of second documents that each contain a link to the first document; and

assigning a freshness score to the first document based on a freshness attribute associated with each document of the set of second documents or the freshness attribute associated with the first document.

12. The method of claim 11, further comprising:

identifying times at which each of the links to the first document existed;

wherein assigning the freshness score to the first document is further based on the identified times.

13. The method of claim 11, wherein assigning a freshness score to the first document is further based on the freshness attribute associated with the first document.

14. The method of claim 11, wherein the set of second documents that each contains a link to the first document are identified if a freshness attribute is not associated with the first document.

15. The method of claim 11, wherein the freshness attribute indicates when each document was last modified or updated.

16. The method of claim 15, wherein the freshness attribute comprises a HTTP “

last-modified-since”

attribute.

17. The method of claim 11, further comprising:

executing a search of a corpus of documents to return results comprising a plurality of documents, wherein the plurality of documents include the first document.

18. The method of claim 17, further comprising:

using the assigned freshness score as one basis for ranking the first document among the plurality of documents returned as the results of the executed search.

19. The method of claim 11, wherein assigning a freshness score to the first document further comprises:

assigning a low freshness score to the first document if more documents of the set of second documents have associated freshness attributes that indicate that the corresponding documents are not fresh.

20. The method of claim 11, wherein assigning a freshness score to the first document further comprises:

assigning a high freshness score to the first document if more documents of the set of second documents have associated freshness attributes that indicate that the corresponding documents are fresh.

21. A system, comprising:

a search engine to;

perform a search of a corpus of documents to return a plurality of documents, wherein the plurality of documents include a first document,

determine whether a freshness associated with the first document can be determined,

identify, when the freshness associated with the first document cannot be determined, a set of second documents that each contain a link to the first document,

determine a freshness associated with each document of the set of second documents,

assign a freshness score to the first document based on the freshness associated with each document of the set of second documents or the freshness associated with the first document, and

rank the first document among the plurality of documents based, at least in part, on the assigned freshness score.

22. A computer-readable medium containing instructions for controlling at least one processor to perform a method of determining the freshness of a first document, the method comprising:

determine whether a freshness associated with the first document can be determined;

identifying, if the freshness associated with the first document cannot be determined, a set of second documents that each contain a link to the first document;

determining a freshness associated with each document of the set of second documents, and

assigning a freshness score to the first document based on the freshness associated with each document of the set of second documents.

23. A method of assigning a freshness score to a first document, comprising:

identifying a set of second documents that each contains a link to the first document;

determining a freshness associated with each document of the set of second documents;

assigning a first freshness score to the first document if more documents of the set of second documents correspond to documents that are not fresh; and

assigning a second freshness score to the first document if more documents of the set of second documents correspond to documents that are fresh, wherein the first freshness score is different than the second freshness score.

24. The method of claim 23, wherein the freshness of a document indicates when the document was last modified or updated.

25. The method of claim 24, wherein the freshness is based on a HTTP “

last-modified-since”

attribute.

26. The method of claim 23, further comprising:

performing a search of a corpus of documents to return results comprising a plurality of documents, wherein the plurality of documents include the first document.

27. The method of claim 26, further comprising:

ranking the first document among the plurality of documents based, at least in part, on the assigned first or second freshness score.

28. A system for determining a freshness of a first document, comprising:

means for identifying a set of second documents that each contain a link to the first document;

means for determining a freshness attribute associated with each document of the set of second documents; and

means for determining a freshness score of the first document based on the freshness attribute associated with each document of the set of second documents.

29. A method of determining the freshness of a first document, comprising:

identifying a set of second documents that each contains a link to the first document;

determining times at which each of the links to the first document existed; and

assigning a freshness score to the first document based on the determined times.

30. The method of claim 29, further comprising:

executing a search of a corpus of documents to return results comprising a plurality of documents, wherein the plurality of documents include the first document.

31. The method of claim 30, further comprising:

using the assigned freshness score as one basis for ranking the first document among the plurality of documents returned as the results of the executed search.

32. The method of claim 29, wherein assigning a freshness score to the first document further comprises:

assigning a low freshness score to the first document if a first number of links that currently point to the first document is smaller than a second number of links that pointed to the first document at some time in the past.

33. The method of claim 29, wherein assigning a freshness score to the first document further comprises:

assigning a high freshness score to the first document if a first number of links that pointed to the first document at some time in the past is smaller than a second number of links that currently point to the first document.

34. The method of claim 29, wherein assigning a freshness score to the first document further comprises:

assigning a low freshness score to the first document if a ratio of a first number of recent links to the first document to a second number of old inks to the first document is larger than a specified threshold value.

35. The method of claim 29, wherein assigning a freshness score to the first document further comprises:

assigning a high freshness score to the first document if a ratio of a first number of recent links to the first document to a second number of old links to the first document is smaller than a specified threshold value.