DETERMINATION OF TIME DEPENDENCY OF SEARCH QUERIES

• US 20090006312A1
• Filed: 06/28/2007
• Published: 01/01/2009
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Liu, Ning, Chen, Zheng, Zhang, Benyu, Yan, Jun, Wang, Jian
• Granted Patent: US 7,693,908 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06Q 30/02 Marketing; Price estimation or determination; Fundraising

Abstract

Techniques for analyzing and modeling the frequency of queries are provided by a query analysis system. A query analysis system analyzes frequencies of a query over time to determine whether the query is time-dependent or time-independent. The query analysis system forecasts the frequency of time-dependent queries based on their periodicities. The query analysis system forecasts the frequency of time-independent queries based on causal relationships with other queries. To forecast the frequency of time-independent queries, the query analysis system analyzes the frequency of a query over time to identify significant increases in the frequency, which are referred to as “query events” or “events.” The query analysis system forecasts frequencies of time-independent queries based on queries with events that tend to causally precede events of the query to be forecasted.

Claims

1. A method in a computing device for analyzing time dependency of a query, the method comprising:

storing frequency of the query at intervals;

calculating values of a frequency spectral for each of a plurality of angular frequencies of the query;

determining whether the values of the frequency spectral include peaks; and

indicating time dependency of the query based on the determination of whether the frequency spectral includes peaks.

2. The method of claim 1 wherein when it is determined that the frequency spectral includes peaks, indicating that the query is time-dependent.

3. The method of claim 2 wherein each identified peak represents a periodicity of the query.

4. The method of claim 1 wherein when it is determined that the frequency spectral does not include a peak, indicating that the query is time-independent.

5. The method of claim 1 wherein the value of the frequency spectral is calculated using a cosine signal hidden periodicity model.

6. The method of claim 5 wherein the value of the frequency spectral for an angular frequency is represented by the following:

$S_N<br><br>\left(\mathrm{\lambda <br><br>}\right)=\underset{t=1}{\overset{N}{\sum <br><br>}}<br><br>q_t<br><br>{\mathrm{<br><br>}}^{-\mathrm{<br><br>}<br><br><br><br>\mathrm{\lambda <br><br>}<br><br><br><br>t}<br><br>\mathrm{\lambda <br><br>}\in <br><br>\left[-\mathrm{\pi <br><br>},\mathrm{\pi <br><br>}\right].$

7. The method of claim 6 wherein a peak is a locally maximum value of the frequency spectral within a range as represented by the following:

$S_N<br><br>\left({\mathrm{\lambda <br><br>}}_j\right)\ge <br><br>S_N<br><br>\left(\mathrm{\lambda <br><br>}\right),<br><br>\mathrm{where}<br><br><br><br>\mathrm{\lambda <br><br>}\in <br><br>\left[{\mathrm{\lambda <br><br>}}_j-\frac{1}{2<br><br>\sqrt{N}},{\mathrm{\lambda <br><br>}}_j+\frac{1}{2<br><br>\sqrt{N}}\right].$

8. The method of claim 1 wherein the query is a query submitted to a search engine service and the stored frequency for an interval represents the number of times the query was submitted to the search engine service during that interval.

9. A computer-readable medium encoded with instructions for controlling a computing device to determine time dependency of a query, by a method comprising:

calculating a value of a frequency spectral for each of a plurality of angular frequencies of the query based on a cosine signal hidden periodicity model;

determining whether the values of the frequency spectral include peaks;

when it is determined that the frequency spectral includes no peak, indicating that the query is time-independent; and

when it is determined that the frequency spectral includes one or more peaks, indicating that the query is time-dependent.

10. The computer-readable medium of claim 9 wherein a peak is a locally maximum value of the frequency spectral.

11. The computer-readable medium of claim 9 wherein each identified peak represents a periodicity of the query.

12. The computer-readable medium of claim 9 wherein a value for the frequency spectral is represented by the following:

$S_N<br><br>\left(\mathrm{\lambda <br><br>}\right)=\underset{t=1}{\overset{N}{\sum <br><br>}}<br><br>q_t<br><br>{\mathrm{<br><br>}}^{-\mathrm{<br><br>}<br><br><br><br>\mathrm{\lambda <br><br>}<br><br><br><br>t}<br><br>\mathrm{\lambda <br><br>}\in <br><br>\left[-\mathrm{\pi <br><br>},\mathrm{\pi <br><br>}\right].$

13. The computer-readable medium of claim 12 wherein a peak is a locally maximum value of the frequency spectral within a range as represented by the following:

$S_N<br><br>\left({\mathrm{\lambda <br><br>}}_j\right)\ge <br><br>S_N<br><br>\left(\mathrm{\lambda <br><br>}\right),<br><br>\mathrm{where}<br><br><br><br>\mathrm{\lambda <br><br>}\in <br><br>\left[{\mathrm{\lambda <br><br>}}_j-\frac{1}{2<br><br>\sqrt{N}},{\mathrm{\lambda <br><br>}}_j+\frac{1}{2<br><br>\sqrt{N}}\right].$

14. The computer-readable medium of claim 12 including adjusting the frequencies to have a zero mean prior to calculating the values of the frequency spectral.

15. The computer-readable medium of claim 9 wherein the query is a query submitted to a search engine service and the frequency for an interval represents the number of times the query was submitted to the search engine service during that interval.

16. The computer-readable medium of claim 9 wherein a periodicity of a query is based on an inverse of the angular frequency of the peak.

17. The computer-readable medium of claim 16 wherein the periodicity is 2π

divided by the angular frequency of the peak.

18. A computing device for determining time dependency of a query, comprising:

a query frequency store storing number of times the query was submitted to a search engine during intervals;

a component that calculates a value of the frequency spectral for each of a plurality of angular frequencies of the query based on a cosine signal hidden periodicity model;

a component that determines whether the values of the frequency spectral includes peaks, each peak being a locally maximum value within a range of angular frequencies that is based on an inverse of the number of intervals; and

a component that, when it is determined that the frequency spectral includes no peak, indicates that the query is time-independent, and when it is determined that the frequency spectral includes one or more peaks, indicates that the query is time-dependent.

19. The computing device of claim 18 wherein each identified peak represents a periodicity of the query.

20. The computing device of claim 18 wherein the periodicity is 2π

divided by the angular frequency of the peak.