The document discusses federated search engines, which allow simultaneous searching of multiple distributed information sources from a single search interface. Federated search engines provide access to the "deep web" that common search engines cannot index. They work by submitting user queries to various deep web resources and aggregating the results. The document compares features of federated search engines to normal search engines. It also outlines criteria for selecting the best federated search engine, and provides examples like MetaLib and WebFeat.

1. FederatedFederated Search EnginesSearch Engines
Paper presented at seminar onPaper presented at seminar on
SEARCH ENGINES AND DATABASESSEARCH ENGINES AND DATABASES
ByBy
Mrs. Shakuntala NighotMrs. Shakuntala Nighot
2009-20102009-2010
SHPT School of Library Science
S.N.D.T. Women’s University
Mumbai 400 020
Under Guidance of
Dr. Sarika Sawant

2. OutlineOutline
Definition- Federated searchDefinition- Federated search
Need for Search EnginesNeed for Search Engines
What is Deep Web?What is Deep Web?
Google search vs. Federated SearchGoogle search vs. Federated Search
Need For Federated Search EnginesNeed For Federated Search Engines
Features, Limitations, Examples of Federated Search EnginesFeatures, Limitations, Examples of Federated Search Engines
Criteria for Selecting Best Federated Search EngineCriteria for Selecting Best Federated Search Engine
MetaLib Vs. WebFeat- A comparative StudyMetaLib Vs. WebFeat- A comparative Study
ConclusionConclusion
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3. Definition - Federated SearchDefinition - Federated Search
““Federated search is the process of performing aFederated search is the process of performing a
simultaneous real-time search of multiple diversesimultaneous real-time search of multiple diverse
and distributed sources from a single search page,and distributed sources from a single search page,
with the federated search engine acting aswith the federated search engine acting as
intermediary.”intermediary.” (Lederman, n,d,)(Lederman, n,d,)
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4. Search Engines-NeedSearch Engines-Need
A web search engine is a tool designed to search forA web search engine is a tool designed to search for
information on wwwinformation on www
E.g.. Yahoo, GoogleE.g.. Yahoo, Google
Need- One needs to refer the catalogue to find toNeed- One needs to refer the catalogue to find to
particular book from the vast collection of the library.particular book from the vast collection of the library.
catalogue acts as an important intermediary betweencatalogue acts as an important intermediary between
library sources and user.library sources and user.
Following the same lines, The Search engine helps theFollowing the same lines, The Search engine helps the
user to sift through ocean of knowledge on World Wideuser to sift through ocean of knowledge on World Wide
Web and to find the specific information needed.Web and to find the specific information needed.
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5. What is Deep Web?What is Deep Web?
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Deep Web is part of World Wide Web other than surfaceDeep Web is part of World Wide Web other than surface
web which cannot be indexed by common searchweb which cannot be indexed by common search
engines.engines.
It is 500 times surface web, Consists of Scholarly andIt is 500 times surface web, Consists of Scholarly and
research materialresearch material
Providers of such contentProviders of such content ::
Database Vendors,Database Vendors,
Commercial Publishers of full-text material,Commercial Publishers of full-text material,
LibrariesLibraries
RepositoriesRepositories

6. Need for Federated Search EnginesNeed for Federated Search Engines
Libraries/Institutions Procure these databasesLibraries/Institutions Procure these databases
Query Language, User interface for each of them isQuery Language, User interface for each of them is
differentdifferent
Patrons don’t prefer searching them one by one.Patrons don’t prefer searching them one by one.
Federated Search Engines offers single interface toFederated Search Engines offers single interface to
search across all resourcessearch across all resources
They give entry to the deep web while Common SearchThey give entry to the deep web while Common Search
engines Can’tengines Can’t
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7. Google vs. Fed. Search EngineGoogle vs. Fed. Search Engine
Google periodically visits the sites on its list andGoogle periodically visits the sites on its list and
identifies the new links at those sites. Following thoseidentifies the new links at those sites. Following those
links it arrives at new pages where it find more links. Inlinks it arrives at new pages where it find more links. In
doing this, Google discovers sites it didn’t knew tilldoing this, Google discovers sites it didn’t knew till
previous visits. And add it its databases.previous visits. And add it its databases.
Process of going from one page to another and then toProcess of going from one page to another and then to
another is referred to as “crawling,”another is referred to as “crawling,”
Deep Web content don’t have such links. Google Can’tDeep Web content don’t have such links. Google Can’t
retrieve it.retrieve it.
Federated Search Engines are programmed to fill up theFederated Search Engines are programmed to fill up the
search form for user queries, submit them to varioussearch form for user queries, submit them to various
deep web resources and to read the results from them.deep web resources and to read the results from them.
Google is not designed to fill up search formsGoogle is not designed to fill up search forms
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8. Federated Search Engines-FeaturesFederated Search Engines-Features
Saves Time/One Stop ShoppingSaves Time/One Stop Shopping
Quality Results –Authentic sourcesQuality Results –Authentic sources
Most current ContentMost current Content
Aggregation (Helpful Arrangement)Aggregation (Helpful Arrangement)
Relevance RankingRelevance Ranking
De-duplicationDe-duplication
Simple Search, Advance Search/ LimitersSimple Search, Advance Search/ Limiters
Clustering/ Subject GroupingClustering/ Subject Grouping 88
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9. Federated Search Engines - LimitationsFederated Search Engines - Limitations
Doesn’t offer native searchDoesn’t offer native search
Hard to go deeper in collectionHard to go deeper in collection
Slow in Response TimeSlow in Response Time
Complete de-duping is difficultComplete de-duping is difficult
Configuring For new database- time consumingConfiguring For new database- time consuming
Changed database configuration- unsearchableChanged database configuration- unsearchable
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10. Some Federated Search ApplicationsSome Federated Search Applications
360 Search360 Search
DeepWebDeepWeb
LiraryFindLiraryFind
MetaLibMetaLib
Scitopeia.orgScitopeia.org
WebFeatWebFeat
WorldWideScienceWorldWideScience
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11. Criteria -Selecting Best FederatedCriteria -Selecting Best Federated
Search EngineSearch Engine
HostingHosting

Vendor Hosted ModelVendor Hosted Model

Locally Hosted ModelLocally Hosted Model
PricingPricing
100% database compatibility100% database compatibility
Screen Scrapping Vs. Native InterfaceScreen Scrapping Vs. Native Interface
Automatic 24*7 Monitoring and updatesAutomatic 24*7 Monitoring and updates
Custom User InterfaceCustom User Interface
Quality of ConnectorsQuality of Connectors
Relevance RankingRelevance Ranking
TrialsTrials
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12. MetaLib Vs WebFeatMetaLib Vs WebFeat
WebFeatWebFeat DeepWebDeepWeb
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Criteria MetaLib Webfeat
1 Shows Search Results in
2 Consistency in results
returned
3 No of databases searched
at a time
4 Option for “Search All
Databases”
5 One Stop Shopping
MetaLib Interface
Yes; All databases
have same search
default operators
Ten
No
No
Native Interface
No; All databases
searched has different
default operators
No Limit
Yes
Yes

13. MeaLib Vs. WebFeatMeaLib Vs. WebFeat
WebFeatWebFeat DeepWebDeepWeb
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Criteria MetaLib Webfeat
6 Speed of retrieval
7 Allows Customized
Grouping of Databases
8 Type of Hosting offered
9 At a time Searching
Capacity of Simple
Search
10 Interface Complexity
11Sorting of Records
offered
More
No
Vendor, Local both
1 Category of subject
Less
By many ways (Year,
relevance etc.)
Comparatively Less
Yes
Vendor
All Categories
More
No sorting

14. ConclusionConclusion
Federated search engines are powerful toolsFederated search engines are powerful tools
which can create a single gateway linking to thewhich can create a single gateway linking to the
scattered information resources, lying even inscattered information resources, lying even in
the deep web.the deep web.
It helps users to find high-quality, mostIt helps users to find high-quality, most
current ,more specialized information fromcurrent ,more specialized information from
remote corners of the Internet. Hence it’s a vitalremote corners of the Internet. Hence it’s a vital
technology in today's information agetechnology in today's information age
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