Advantages of Query Biased Summaries in Information Retrieval by A. Tombros and M. Sanderson - PowerPoint PPT Presentation

About This Presentation
Title:

Advantages of Query Biased Summaries in Information Retrieval by A. Tombros and M. Sanderson

Description:

Advantages of Query Biased Summaries in Information Retrieval by A. Tombros and M. Sanderson Presenters: Omer Erdil Albayrak Bilge Koroglu Outline Brief Introduction ... – PowerPoint PPT presentation

Number of Views:171
Avg rating:3.0/5.0
Slides: 13
Provided by: Bilg155
Category:

less

Transcript and Presenter's Notes

Title: Advantages of Query Biased Summaries in Information Retrieval by A. Tombros and M. Sanderson


1
Advantages of Query Biased Summaries in
Information Retrievalby A. Tombros and M.
Sanderson
  • Presenters
  • Omer Erdil Albayrak
  • Bilge Koroglu

2
Outline
  • Brief Introduction to Typical Information
    Retrieval System
  • Why query biased summaries needed?
  • How a query biased summary generated?
  • Experimental Environment
  • Experimental Results
  • Conclusion and Future Works

3
Introduction
  • Typical IR System
  • input information need
  • output ranked document list

Figure 1. Screenshot from an IR System
4
Introduction (cont...)
  • Deciding whether the retrieved document is worth
    to further investigation
  • Examining the static summaries
  • Checking the whole content
  • Weak content indicators static summaries
  • Time consuming job refering full text nearly all
    times
  • Aiming to minimise reaching whole content
  • Generating query biased summaries

5
Generating Query Biased Summaries
  • Query-specific summaries for each retrieved
    document
  • Classical approach to summarization
  • Extracting sentences
  • Assigning scores to sentences
  • Selection of best-scoring sentences
  • Some modification on score assignment
  • Extra importance to titles and subtitles
  • More weights to sentences with clusters of terms
  • Additional points to sentences includes query
    terms

6
Experimental Environment
  • TREC test collection Wall Street Journal news
  • 50 queries of which relevant documents are known
  • 2 groups of 10 postgraduate students to find
    relevant docs for 50 queries
  • One group with static summaries
  • Another is to use query biased summaries
  • 50 retrieved docs per each query
  • 5 queries per student
  • 5 minutes allocated per query
  • Identical computers in hardware/software aspects

7
Experimental Environment (cont...)
Figure 2. The subjects performing on query biased
static summaries in the experiments
8
Experimental Results
  • Recall the ratio of total number of relevant
    documents for query to the number of retrieved
    relevant documents
  • Precision the ratio of total number of retrieved
    documents for query to the number of retrieved
    relevant documents

Figure 5. Precision values of 2 groups
Figure 4. Recall values of 2 groups
9
Experimental Results (cont...)
  • Speed of evaluators judgments of relevancy
  • 2.62 on 20 documents corresponds 13 increase of
    average number of examined documents

Figure 6. The number of doc percentage for 2
group
10
Experimental Results (cont...)
  • The need for checking full text
  • Average number of full text reference per query
  • query biased summary group 0.3
  • static summary group 4.74

Figure 7. Average number of references to the
full text of documents per query
11
Conclusion and Future Works
  • Effective method employing query biased
    summaries in IR Systems
  • Easily identifiable more relevant documents
  • Decreasing the need to check whole content of
    document
  • Applicable to web search engines
  • Expensive to retrieve the documenst from slow,
    not reliable, and remote servers
  • Requiring to manage an index file
  • More experiments on different summarization
    methods with different datasets

12
  • Thank you...
Write a Comment
User Comments (0)
About PowerShow.com