Federated Searching
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Federated Searching
Rex KrajewskiReference Services Librarian
Simmons Collegeweb.simmons.edu/~krajewsk/library/federatedsearching.html
Federated Searching AKA
parallel search meta search broadcast search one-search cross searching cross-database searching distributed searching single search
Well-known Models
Dialog allows user to search many databases simultaneously (think: Dialindex One Search Categories)
Metasearch Engines—like Dogpile, Clusty, Mamma, and Metacrawler—allow users to search multiple search engines’ top results with a single search
Federated Searching
The term “federated searching” came from the Open Archives Initiative’s Protocol for Metadata Harvesting (OIA-PMH)
Single server harvests metadata for records from the holdings databases of “federated” databases. The resulting centralized data is searchable.
What’s in a name?
NISO says “metasearching” Vendors prefer “federated
search engines” because metasearching use by meta-search engines like Dogpile, Mamma, and Ask Jeeves.
Federated vs. Meta
Meta search engines aggregate material that has already been searched and is freely available to anyone on the Web.
Federated search engines run searches at the time they are queried and can include proprietary material and other Internet content not spidered by search engines
Why Federated Searching?
Libraries offer hundreds of databases to search
Allows libraries and users alike to manage the hundreds of database search tools.
Digital Reference: Why?
97% of surveyed adult internet users expect to find the information they need on government, health, commerce, and news on the internet.*
*Counting on the Internet: Most expect to find key information online, most find the information they seek,many now turn to the Internet first, Pew Internet& American Life Project,
29 September 2002, Date accessed: 15 November 2005.
Digital Reference: Why?
“Nearly three-quarters (73%) of college students say they use the Internet more than the library, while only 9% said they use the library more than the Internet for information searching.”*
*The Internet Goes to College: How Students are Living in the Future with Today's Technology, Pew Internet& American Life Project,15 September 2002, Date accessed: 03 November 2005.
Digital Reference: Why?
“71% of students report using the Internet at their primary source for their last major project, and they also report accessing online study aids like Sparknotes or CliffNotes.”*
*The Internet and Education, Pew Internet& American Life Project,01 September, 2001, Date accessed: 21 October, 2005
Why Federated Searching
In the age of Google, users expect the world of knowledge available quickly and easily at their fingertips…they expect the same kind of one-stop searching to be available in the library
What does the user see?
A single research entry point
A familiar interface A consistent search syntax
How It Plays Out
Federated search engine translates query into syntax of multiple resource
wom#n and sport*
women and sports
(woman or women) and sport!
women and sports
How do they do it?
Federated search engines translate single search query into syntax of multiple databases:
Z39.50 XML Gateways HTTP Protocol “Others”
How It Plays Out
Individual resources execute search based on the query supplied by the federated search engine wom#n and sport*
(woman or women) and sport!
women and sports
Federated Search Engines
Search multiple databases: E-Journals Abstracting and indexing databases E-Books Web Online catalog(s) Any other searchable online source
How It Plays Out
Federated search engine aggregates results
Results
ResultsResults
Results
Results
Results
Results
+
How It Plays Out
Searcher receives a single list of all the results from all the resources searched by the federated search engine
ResultsResults
Value added in results
Federated search engines deliver results from multiple databases in a single list:
Standardized format De-duped Connect to fulltext using link
resolvers Relevancy ranked
What are they selling?
The technology behind federated searching is straight-forward enough to prompt one industry insider to describe it as a “commodity.”
The Major Players
The major players attempt to distinguish themselves by adding value to the basic technology:
Maintaining linksUpdating translators to remain
compatible with search interfacesResults delivery: de-duping, ranking,
sorting, fulltext linking, etc.
What’s not to love?
One-stop searching No danger of missing a possible
source of information Users do not have to figure out
where to start…just search them all Those expensive databases won’t
be missed by searchers who could use them
What’s not to love?
The whole process of research—even for scholarly, technical, and professional information—
has been Googlized!
Not for Power Searching
The searching syntax among databases vary:
Truncation, Boolean searching, phrase searching, and proximity searching may be lost
Use of limits is limited Searchable fields may be eliminated—
controlled vocabularies lose their punch
Even keyword searching tough. MS = Microsoft or multiple sclerosis
May not be all they claim
True de-duping is virtually impossible
Too many variables for reliable relevancy ranking
Sorting—a single basket for apples and oranges?
Still Has Much to Improve
Access and verification—especially “off-site” users
Not all federated search engines can search all sources—not everyone is using the Z39.50 or XML protocol
Expensive and labor intensive