Meta Data and Search
Metadata is information about information: more precisely, it's structured information about resources. It can be as simple as an author's name or as complex as a geographic code or a controlled-vocabulary subject heading. Library catalogs are remote meta data, as are book reviews, indexes to art collections and summaries. Some document formats allow metadata to be incorporated into documents or records, such as HTML <meta> tags and Dublin Core tags, MP3 ID3 fields, Microsoft Office Properties, Adobe XAP data, and database keyword fields.
Metadata generally uses a more controlled vocabulary and it provides the context of the words, so it provides more scope for locating useful information with the best recall and precision. For example, metadata can indicate whether an article containing the name "Tim Berners-Lee" is by him or about him, which can often be valuable to searchers. Standard date formats allow for accurate date range searching and sorting. Metadata can be an interface between internal codes and human-readable names, letting people find information the way they want it, rather than the way applications manage it.
Many content management and publishing systems provide metadata tools, which allow authors, editors, and librarians to add appropriate entries more easily, and use standard vocabulary and formatting. However, this is not yet a standard part of web publishing.
Metadata on most sites has significant limits: many documents lack metadata, few search engines recognize additional metadata fields or tags, there is no way to tell if the metadata is accurate, misspellings and typos are common, word meanings change over time, and choosing accurate keywords and categories is difficult. Editing and managing metadata requires a significant investment of resources.
All this makes metadata or keyword search engines, which search only the assigned key words rather than the text of a document, much less useful and valuable than fulltext search engines. When full text search engines index metadata content and use it to improve search rankings, this is the best of both worlds.
Resources
- Faceted Metadata Search and Browse SearchTools Report
- A new approach to search and browse using extensive metadata.
- Controlled Vocabulary.com
- Makes a strong case for using a standard listing of subject terms for
best retrieval. Includes listings of books and resources.
- Digital Libraries: Metadata Resources
- Beautiful and complete listing of resources, including SOIF
and RDM.
- UKOLN Metadata
- Good links and information about Metadata in general and more from the
UK Office for Library and Information Networking.
- Meta Matters
- A service of the National Library of Australia, providing information
on metadata and Dublin Core.
- XML.com Metadata
- Metadata from an XML point of view, including RDF.
- Introduction to Metadata Getty Research Institute, second edition, July 2001
- Articles on topics related to metadata cataloging and retrieval on the
web.
- Adobe XMP
- This eXtensible Metadata Platform is an XML framework for Adobe products, allowing them to store metadata about documents within the file binary source (previously called XAP). The open-source license SDK allows other applications to access the metadata without having to parse the file contents. The metadata, based on RDF, describes the contents of the file using standards including Dublin Core tags, asset management, rights management and custom schemas. As of October 2001, no search engines can read this information, but we expect this to change in the near future.
Articles & Books
- Faceted Classification of Information The Knowlege Management Connection, May 2004
- A nice look at the basics of faceted classification, which results in metadata. This article contrasts traditional library systems based on Ranganathan with business and organizational knowledge classification, for an enterprise intranet or KM system.
- Metadata: What is
it and Why is it Important Biosafety Clearing-House, January 30
2002
- A good general introduction, describing many values of metadata. Makes the points that it preserves the internally investment in the data, promotes data sharing and improves interoperability. Provides an example of use in biology for Dublin Core and RDF.
Why metadata is important New Thinking Newsletter, October 1, 2001 by Gerry McGovern- A plea for implementing metadata, mainly to help people find content
in the "torturous mazes" of Intranets.
- Metadata in a nutshell Information Europe, Summer 2001 by Michael Day
- Helpful short introduction.
- Using Metadata to Improve Local Searching Exploit Interactive; April 2000 by Brian Kelly
- Using Dublin Core metadata to search by issue number, type of article and funding agencies.
- Metadata: Cataloging by Any Other Name Online Magazine; January 1999 by Jessica Milstead and Susan Feldman
- A librarian-oriented article on the value of metadata as consistent
descriptions of information objects. Discusses text and multimedia objects,
formats of metadata, standards and software. Describes how search engines
can use appropriate metadata to improve relevance results.
- A new dawn New Scientist, 30 May 1998 by Glyn Moody (subscription required)
- Describes the potential for XML, searching, XSL style sheets, XLink
link extensions, RDF metadata, Dublin Core, and more.
- Metadata: An Overview Paper given by Dr. Warwick Cathro, Assistant Director-General, Services to Libraries Division at the Standards Australia Seminar, "Matching Discovery and Recovery" August 1997.
- Describes the concepts and background of meta data as a tool to improve
the retrieval of information, especially for web wide search tools. Covers
the Warwick Framework and the Dublin Core efforts to provide standard
tags and other meta data elements in some detail.
- Who Will Master Metadata? Network Computing Online, by Christine Hudgins-Bonafield.
- Business-oriented analysis of how software developers such as Infoseek,
Bunyip, IBM and Microsoft are working with librarians to set metadata
standards.
- Web architecture: Metadata Tim Berners-Lee, 1997
- The inventor of the World Wide Web was thinking about the value of metadata in finding resources, providing self-describing information.
And, for another point of view:
- Metacrap: Putting the torch to seven straw-men of the meta-utopia May - August 2001, by Cory Doctorow
- Considers the problems of creating consistent quality metadata to be insurmountable. These are defined as: lies, laziness, stupidity, lack of self-knowledge, schema bias, metrics bias, and language issue