1. IST 497E Information Retrieval and Organization
Meta Search
IST 497 E Meta-Search, Pradeep Teregowda

2. Overview What is a Meta Search Engine Features Differences
Architecture
Some Meta Search Engines
Conclusions and Future ?

4. Overview What is a Meta Search Engine ? Traveling Further
Why Meta Search ?

5. What Is a Meta Search Engine ?
Dictionary meaning for Meta:
“more comprehensive : transcending.”- webster.com
Simple Explanation
“A Meta Search engine allows you to search multiple search engines at once, returning more comprehensive and relevant results, fast.” –MetaCrawler {modified}

6. Traveling Further A little bit of History:
Started with Harvest (1995) –[Ref: Information Discovery and Access System – C. Mic Bowman et al].
Was developed for gathering information from repositories, building topic-specific content indexes, web-caching,flexible searching.
In many ways current Meta Search engines have similar aims.

7. Why Are Meta Search Engines Useful ?
Meta Search improves the Search Quality in many ways:
Comprehensive,
Efficient,
One query queries all {one-click paradigm},

8. Why Meta Search ?
Individual Search engines don’t cover all the web by themselves,
Individual Search Engines are prone to spamming {people trying to raise their ranking profile. In a non-legitimate manner or to promote commerce},
Difficulty in deciding and obtaining results with combined searches on different search engines,

9. Why Meta Search ? Data Fusion {multiple formats supported},
In Case of niche search engines provides the ‘big picture’,
Takes less effort.

10. Overview
Features

11. Features.
Unifies the Search Interface and provides a consistent user interface,
Standardizes the query structure,
May make use of an independent ranking method for the results {rank-merging},
May have an independent ranking system for each search engine/database it searches,
Meta Search is not a search for Meta Data.

12. Overview
Differences
Differences {Search vs. Meta Search}.

13. Differences {Search Vs. Meta-search}
Doesn’t generally have a Database by itself,
Does not search{crawl} the web.
A Meta-Search Engine in terms of search engine.
Essentially is a hub of search engines/databases accessible by a common interface providing the user with results which may/may not be ranked independently of the original search engine/source ranking.

14. Overview Architecture/Internals A block representation,
What do those blocks do ?,
Queries,
Ranking.

15. Architecture Feedback Knowledge Personalize Dispatcher Query
User Interface
User
S E 1
S E 2
S E 3
Web
Display

16. What Do Those Blocks Do ? User Interface Dispatcher
Normally resemble search engine interfaces with options for
Types of search [Media]
Search Engines to Use
Dispatcher
Generates actual queries to the search engines by using the user query
May involve choosing/expanding search engines to use

17. What Do Those Blocks Do ? Display. Personalization/Knowledge.
Generates Results page from the replies received, May involve ranking,parsing,clustering of the search results or just plain stitching.
Personalization/Knowledge.
May contain either or both. Personalization may involve weighting of search results/query/engine for each user.

18. Queries STARTS { protocol }. Inquirus: Expand Queries.
A simple protocol that text search engines should follow to facilitate searching and indexing multiple collections of text documents.
Choosing best source for a query,
Evaluating a query at those sources,
Merging the query results from them.
Inquirus: Expand Queries.
Ex: (What does Satellite stand for = Satellite stands for).

19. Independent Ranking Stitch together the results [Dogpile],
Selection of a particular Search Engine based on a query – a meta index [SavySearch-Resource Balancing],
Rank merging based on Search Engine rating [MetaCrawler],
Context analysis for search results with respect to the query [Inquirus].

20. Fusion of Other Media Inquirus. Motivation for a meta-search {Images}:
Queries from the user can be modified, since individual search engines are good at different types of queries the results are very good.
How ?
See Reference {Skipped because of topic overlap}.
Can it work for others ?
Example: FTP,Music – Probably yes [P2P searches].

21. Other Work Other work {Media Fusion}. MetaSEEk. Ixquick. Dogpile.
Visual Search Engine [for images],
Makes use of query by example.
Ixquick.
MP3,Images,News.[all come from different search interfaces –may not exactly be fusion].
Dogpile.
Multimedia,Images,News,Files.

23. Overview Some Meta Search Engines On the web,
Why are they not so popular ?,
Some Reviews.

24. Meta search Engines on the Web
MetaCrawler,
Ixquick,
Inquirus,
SavySearch {now cnet search ?},
Dogpile,
Sherlockhound,
Vivisimo.

25. Why Are They Not So Popular ?
Ads !
Some Meta Search engines pick up ads as part of search results from the participating search engines.
Example: Dogpile.
Similar reasons as general search engines (ads clutter search results).
Example: MetaCrawler,Ixquick.
Paid Placement Search Engines included,
Relation with the search engines they depend on. {load,interaction}….

26. Why Are They Not So Popular ?
Results as good as the worst search engine in the group.
Combining results using meta-index and rankings can lead to incorrectly ranked results from a search engine reducing the relevance of correct results.
If your highly ranked search engine returns a badly ranked result, then your results are also badly ranked.

27. Some Reviews Search Engine Watch [May 2001] Meta Search Engine
% Results From A Major Search Engine
Vivisimo
100 % [No Ads]
Ixquick
70 %
MetaCrawler
48 %
Dogpile
14%

28. Overview
Conclusions and Future

29. Conclusions and Future
Vivisimo reported 43 % increase in traffic –[wired.com Aug. 14, 2001],
Apple ‘Sherlock’ has been popular,
Multiple Media Search,
P2P Searches ?,
Growth or Niche Search Engines.

30. References
The MetaCrawler Architecture for Resource Aggregation on the web(1997) – Erik Selberg & Oren Etzioni.
Context and Page Analysis for Improved Web Search(1998) –Steve Lawrence & C. Lee Giles.
Experiences with Selecting Search Engines Using Metasearch(1997) – Daniel Dreilinger & Adele E. Howe.

31. Time to Wake Up…

33. Web References Search Engine Watch Article [Meta Search Or Meta Ads?],
Wired Article [Searching For Google’s Successor],
MetaSEEk [Writeup],
Text and Image Meta Search on the Web [Citeseer Paper Reference].