Page reranking system and page reranking program to improve search result

• US 20070118521A1
• Filed: 11/17/2006
• Published: 05/24/2007
• Est. Priority Date: 11/18/2005
• Status: Abandoned Application

• Current Assignee: National Institute of Information and Communications Technology
• Original Assignee: National Institute of Information and Communications Technology
• Inventors: Tanaka, Katsumi, Jatowt, Adam, Kawai, Yukiko
• Application Number:
  US11/601,260
• Publication Number:
  US 20070118521A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques

Abstract

A page reranking system is a system that grants renewed page rankings to multiple Web pages that are obtained as search result pages in compliance with a user'"'"'s query and to which page rankings are granted by calculating a change rate of a page content between multiple versions of each of the Web pages, and comprises a reranking device that grants the renewed page ranking to each of the Web pages based on the change rate of the page content between multiple versions calculated for each of the Web pages.

Claims

1. A page reranking system that is a system that grants renewed page rankings to multiple Web pages that are obtained as search result pages in compliance with a user'"'"'s query and to which page rankings are granted by calculating a change rate of a page content between multiple versions of each of the Web pages, wherein the page reranking system comprises a reranking device that grants the renewed page ranking to each of the Web pages based on the change rate of the page content between the multiple versions of each of the Web pages updated in compliance with the user'"'"'s query and calculated for each of the Web pages.

2. The page reranking system described in claim 1, wherein the reranking device comprises either one of or both of a first reranking processing device that refers to a Web archive device memorizing the Web pages that existed on the Internet in the past and that conducts a reranking process to each of the Web pages based on the change rate of the page content between the multiple versions of each of the Web pages updated in compliance with the user'"'"'s query and

a second reranking processing device that conducts a reranking process to each of the Web pages based on the change rate of the page content updated in compliance with the user'"'"'s query between an indexed page version of each Web page cached as the search result page and a present page version of each Web page existing on the Internet, and

the reranking processing is conducted to each of the Web pages by the use of either one of or both of the first reranking processing device and the second reranking processing device.

3. The page reranking system described in claim 2, wherein the first reranking processing device comprises

a change rate calculating device that calculates the change rate of the page content between the multiple versions of each of the Web pages updated in compliance with the user'"'"'s query,

a first permutation ranking determining device that determines a permutation ranking in order to permutate the multiple Web pages in an ascending order or a descending order based on the change rate of the page content calculated by the change rate calculating device, and

a first ranking granting device that grants a renewed page ranking corresponding to the permutation ranking determined by the first permutation ranking determining device to each of the Web pages.

4. The page reranking system described in claim 3, wherein the change rate calculating device calculates a temporal quality of the page content between the multiple versions for each of the Web pages as the change rate of the page content.

5. The page reranking system described in claim 4, wherein the temporal quality is calculated by the following equation,

$\begin{array}{c}(\mathrm{Equation}\end{array}$

 

⁢

1 )  

T ⁢

 

⁢

Q = ⁢

1 ∑

j = 1 j = n - 1 ⁢

1 ( T present - T j ) * ⁢

∑

j = 1 j = n - 1 ⁢

{ 1 ( T present - T j past ) * cos ⁢

 

⁢

( A ( j , j + 1 ) c , Q ) ( T j + 1 - T j ) * ( 1 + S ( j , j + 1 ) c S j ) } ( 1 )

Here, n is the number of past page versions, A^c_(j,j+1) is the vector of added changes between the j and j+1 versions of the page, cos (A^c_(j,j+1), Q) is the cosine similarity between vector A^c_(j,j+1) and query vector Q, S^c_(j,j+1) is the size of the added change between the j and j+1 versions of the page, S_j is the total size (total number of words) of the j version expressed as the number of words, T_j and T_j+1 are the timestamps of the consecutive past versions of the page, T^present is the time when the query was issued, and T_j^past is equal to T_j.

6. The page reranking system described in claim 3, wherein the first ranking granting device grants the renewed page ranking to only the Web page whose ranking is upper than a predetermined order in the permutation ranking determined by the first permutation ranking determining device.

7. The page reranking system described in claim 2, wherein the Web archive device memorizes the Web page that existed on the Internet in the past and version administrating information such as year-month-day that can administrate the version of the Web page in a mutually associated manner.

8. The page reranking system described in claim 2, wherein the first reranking processing device obtains a change of the page content between every consecutive pair of versions of the Web pages archived by the Web archive device in case of calculating the change rate of the page content.

9. The page reranking system described in claim 2 , wherein the second reranking processing device comprises

a page ranking value calculating device that calculates a page ranking value in order to set a renewed page ranking based on the change rate of the page content updated in compliance with the user'"'"'s query between the indexed page version and the present page version for each of the Web pages,

a second permutation ranking determining device that determines a permutation ranking in order to permutate the multiple Web pages in an ascending order or a descending order based on the page ranking value calculated by the page ranking value calculating device, and a second ranking granting device that grants a renewed page ranking corresponding to the permutation ranking determined by the second permutation ranking determining device to each of the Web pages.

10. The page reranking system described in claim 9, wherein the page ranking value is calculated by the following equation.

$\begin{array}{c}(\mathrm{Equation}\end{array}$

 

⁢

2 )  

R i new = ⁢

[ cos ⁢

 

⁢

( A i , Q ) - α

* cos ⁡

( D i , Q ) + 1 β

* ( T present - T i indexed ) + 1 ] * ⁢

[ 1 + γ

* N - R i se + 1 N ] * [ 1 + η

* ( S i a S i indexed + μ

* S i d S i indexed ) ] ( 2 )

cos (A_i, Q) is the cosine similarity between the vector of additions A_i for the page i and the query vector Q, cos.(D_i, Q) is the cosine similarity between the vector of deletions D_i for the page i and the query vector Q, R^se_i is the original ranking assigned to the page by a search engine, T^indexed_i is the date when the search engine indexed the page, T^present is the present time when the query is issued, and S^a_i, S^d_i, S^indexed_i denote the number of words in additions (the number of added words), deletions (the number of deleted words), and in the indexed version (total number of words) of the page, respectively. And α

, β

, γ

, η

, and λ

are the weights used to adjust the effects of the features on the renewed ranking. In addition, N is a total number of URLs as being an object to be reranked among a number of search result URLs obtained by the search engine.

11. The page reranking system described in claim 9, wherein the second ranking granting device grants the renewed page ranking to only the Web page whose ranking is upper than a predetermined order in the permutation ranking determined by the second permutation ranking determining device.

12. The page reranking system described in claim 1, wherein the search result page is obtained by a searching process by the use of a Web search engine.

13. A page reranking program that is a program to operate a computer so as to grant renewed page rankings to multiple Web pages that are obtained as search result pages in compliance with a user'"'"'s query and to which page rankings are granted by calculating a change rate of a page content between multiple versions of each of the Web pages,

and the page reranking program makes the computer function as a reranking device that grants the renewed page ranking to each of the Web pages based on the change rate of the page content between the multiple versions updated in compliance with the user'"'"'s query calculated for each of the Web pages.

14. The page reranking program described in claim 13, wherein the reranking device comprises either one of or both of

a function as a first reranking device that refers to a Web archive device memorizing the Web pages that existed on the Internet in the past and that conducts a reranking process to each of the Web pages based on the change rate of the page content updated in compliance with the user'"'"'s query between multiple versions, and

a function as a second reranking device that conducts a reranking process to each of the Web pages based on the change rate of the page content updated in compliance with the user'"'"'s query between an indexed page version cached as the search result page and a present page version existing on the Internet,

and the reranking processing is conducted to each of the Web pages by the use of either one of or both of the first reranking processing device and the second reranking processing device.

15. The page reranking program described in claim 14, wherein the first reranking processing device comprises

a function as a change rate calculating device that calculates the change rate of the page content updated in compliance with the user'"'"'s query between the multiple versions of each of the Web pages, a function as a first permutation ranking determining device that determines a permutation ranking in order to permutate the multiple Web pages in an ascending order or a descending order based on the change rate of the page content calculated by the change rate calculating device, and

a function as a first ranking granting device that grants a renewed page ranking corresponding to the permutation ranking determined by the first permutation ranking determining device to each of the Web pages.

16. The page reranking program described in claim 14, wherein the second reranking processing device comprises

a function as a page ranking value calculating device that calculates a page ranking value in order to set a renewed page ranking based on the change rate of the page content updated in compliance with the user'"'"'s query between the indexed page version and the present page version for each of the Web pages,

a function as a second permutation ranking determining device that determines a permutation ranking in order to permutate the multiple Web pages in an ascending order or a descending order based on the page ranking value calculated by the page ranking value calculating device, and

a function as a second ranking granting device that grants a renewed page ranking corresponding to the permutation ranking determined by the second permutation ranking determining device to each of the Web pages.