huizhong doan yonbo cao chin yew lin and yong yu shanghai jiao tong university msra acl 2008 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Searching Question by Identifying Question Topic and Question Focus PowerPoint Presentation
Download Presentation
Searching Question by Identifying Question Topic and Question Focus

Loading in 2 Seconds...

play fullscreen
1 / 25

Searching Question by Identifying Question Topic and Question Focus - PowerPoint PPT Presentation


  • 134 Views
  • Uploaded on

Huizhong Doan, Yonbo Cao, Chin-Yew Lin and Yong Yu Shanghai Jiao Tong University & MSRA ACL 2008. Searching Question by Identifying Question Topic and Question Focus. Introduction. Question & their Answers A very large archives Built up by Online Services Example

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Searching Question by Identifying Question Topic and Question Focus' - zorita-craig


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
introduction
Introduction
  • Question & their Answers
    • A very large archives
    • Built up by Online Services
  • Example
    • Traditional FAQ services
    • Community-based Q&A services
      • Emerging
      • Yahoo! Answers, Live QnA, BaiduZhidao

Rick Liu

motivation
Motivation
  • Question Search
  • Help users to search previous answers

Any cool clubs in Berlin or Hamburg?

What are the best/most fun clubs in Berlin?

  • Any nice hotels in Berlin or Hamburg?
  • How long does it take to Hamburg from Berlin?
  • Cheap hotels in Berlin?

Rick Liu

motivation1
Motivation

Any cool clubs in Berlin or Hamburg?

Question Focus

Question Topic

Rick Liu

approach
Approach
  • Identifying question topic & focus
    • Question tree
    • Determining the tree cut
  • Modeling question topic & focus for search
    • Language model

Rick Liu

question tree
Question Tree
  • Topic terms
    • BaseNP, WH-ngram
  • Topic profile
    • probability distribution of categories
  • Specificity
    • inverse of the entropy of the topic profile
  • Topic chain
    • topic terms ordered by specificity value (desc)
  • Topic tree

Rick Liu

tree cut model
Tree Cut Model
  • M = ( Γ , θ )
    • Γ = [ C1, C2, .. Ck ] , tree cut
    • Θ = [ P(C1), P(C2), .. P(Ck) ] , probparam vector
  • A cut is any set of nodes
  • Σi=1..kP( Ci ) = 1

Rick Liu

tree cut model example
Tree Cut Model Example

[n0, n11], [n12, n21, n22, n23], [n13, n24]

[n11, n21, n22, n23, n24]

Rick Liu

mdl base tree cut model
MDL-base Tree Cut Model
  • Minimum Description Length

Ref : Li and Abe, 1998

Rick Liu

determining the tree cut
Determining the Tree Cut

TAIL

HEAD

Rick Liu

modeling for search
Modeling for Search
  • P( q | q )
    • q : queried question
    • q : targeted question

~

~

Rick Liu

experimental data
Experimental Data
  • Yahoo! Answers
  • Resolved questions
    • travel : 314,616 items
    • computers & internet : 210,785 items
  • Tree fields
    • title ( only used )
    • description
    • answers

Rick Liu

ground truth
Ground Truth
  • Employed Vector Space Model
  • Manual judgments : relevant / irrelevant
  • Baseline : VSM, LMIR
  • Evaluation : MAP, R-precision, MRR

Rick Liu

about the
About the λ

Emphasize more in question topic

Rick Liu

error analysis travel
Error Analysis ( travel )
  • Examine the correctness of question topics and question foci
  • 200 queried question => 69 question incorrect
    • (a) Only have the head part ( 59 )
    • (b) Incorrect order ( 10 )
  • (a) explains why λ is 0.7

Rick Liu

related work
Related Work
  • FAQ data
  • Community based
    • Jeon et al., 2005
    • Compared four different retrieval methods
      • Vector space model
      • Okapi
      • Language model
      • Translation-based model
    • Translation-based model performed the best

Rick Liu

translation model
Translation Model
  • Lexical chasm
    • Where to stay in Hamburg?
    • The best hotel in Hamburg?
  • IBM model 1
    • Use question titles and question description as the parallel corpus

Rick Liu

results
Results

Rick Liu

conclusions and future work
Conclusions and Future Work
  • Data Structure
  • Use MDL-based Tree Cut Model to Identify
  • A new form of language modeling for question search
  • Extensive experiments
  • Now only community-based
  • From forum sites / FAQ sites

Rick Liu

thanks
Thanks

Rick Liu