Frequently Asked Questions
- Question
What is a metasearch/federated search?
- Answer
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The terms “metasearch” and “federated search” are often used interchangeably to mean a search feature that allows searching across multiple data sources simultaneously. Some library science types further differentiate these terms:
- metasearch: a search of a single database of pooled metadata that may have been harvested, indexed, and maintained separately from the content that it describes,
- federated search: searching multiple databases in different locations simultaneously
However, for the average person, these distinctions are probably not significant. It might be helpful, however, to understand that a federated or cross-database search has to search across a number of databases from different vendors that are using different search protocols, various verification and authentication methods, and different descriptors for data and content tags or fields. The effectiveness of this process can vary in terms of speed, quality, presentation of results, and access to full-text and other features. Several products that make such searching a reality are now available, including WebFeat, which is the current metasearch or federated search tool used in GALILEO.
Most products utilize one or more search methods:
- The Z39.50 protocol, a pre-Web standard for searching and retrieving information from databases, can search one or more databases at the same time. Z39.50 is still in use for searching library catalogs and databases and is utilized as a key method in some federated search products; however, all databases are not Z39.50 compliant.
- XML gateway, a web application that enables a federated search using XML tags.
- HTML parsing, or “screen-scraping,” which is a way of translating data found on non-structured HTML pages through the use of special mappings called HTTP connectors or translators.
All federated search products offer a knowledge base of information about how to search different resources. Their differences lie in which methods they use, the number and types of resources they can search, their service models, their features, and interface flexibility.
While the single search box appears to be a “Googlization” of the library search interface, the federated search tool goes beyond the open Internet to find data considered to be buried on the “deep” web beneath layers of verification and authentication. Each resource in a federated search must be configured correctly for authentication to work seamlessly. Standards have not been established for this young technology, but a group called the NISO Metasearch Initiative is at work on standardizing access protocols, record formats, and semantics of data.
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Keywords: cross-database searching metasearching metadata federated search
Last Updated: Fri, January 22, 2010 - 11:37:15