An index term, subject term, subject heading, or descriptor, in information retrieval Information retrieval is the science of searching for documents, for information within documents, and for metadata about documents, as well as that of searching relational databases and the World Wide Web. There is overlap in the usage of the terms data retrieval, document retrieval, information retrieval, and text retrieval, but each also has, is a term that captures the essence of the topic of a document. Index terms make up a controlled vocabulary for use in bibliographic records. They are an integral part of bibliographic control, which is the function by which libraries collect, organize and disseminate documents. They are used as keywords to retrieve documents in an information system, for instance, a catalog or a search engine A web search engine is a tool designed to search for information on the World Wide Web. The search results are usually presented in a list and are commonly called hits. The information may consist of web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike Web. A popular form of keywords on the web are tags In online computer systems terminology, a tag is a non-hierarchical keyword or term assigned to a piece of information . This kind of metadata helps describe an item and allows it to be found again by browsing or searching. Tags are chosen informally and personally by the item's creator or by its viewer, depending on the system which are directly visible and can be assigned by non-experts also. Index terms can consist of a word, phrase, or alphanumerical term. They are created by analyzing the document either manually with subject indexing Subject indexing is the act of describing a document by index terms to indicate what the document is about or to summarize its content. Indexes are constructed, separately, on three distinct levels: terms in a document such as a book; objects in a collection such as a library; and documents within a field of knowledge or automatically with automatic indexing Search engine indexing collects, parses, and stores data to facilitate fast and accurate information retrieval. Index design incorporates interdisciplinary concepts from linguistics, cognitive psychology, mathematics, informatics, physics and computer science. An alternate name for the process in the context of search engines designed to find web or more sophisticated methods of keyword extraction. Index terms can either come from a controlled vocabulary Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing schemes, subject headings, thesauri and taxonomies. Controlled vocabulary schemes mandate the use of predefined, authorised terms that have been preselected by the designer of the vocabulary, in contrast to natural language or be freely assigned.
Keywords are stored in a search index Search engine indexing collects, parses, and stores data to facilitate fast and accurate information retrieval. Index design incorporates interdisciplinary concepts from linguistics, cognitive psychology, mathematics, informatics, physics and computer science. An alternate name for the process in the context of search engines designed to find web. Common words like articles An article is a word that combines with a noun to indicate the type of reference being made by the noun, and may also specify the volume or numerical scope of that reference. The articles in the English language are the and a . An article is sometimes called a noun marker, although this is generally considered to be an archaic term (a, an, the) and conjunctions (and, or, but) are not treated as keywords because it is inefficient to do so. Almost every English-language site on the Internet has the article "the", and so it makes no sense to search for it. The most popular search engine, Google Google Inc. is an American public corporation, earning revenue from advertising related to its Internet search, e-mail, online mapping, office productivity, social networking, and video sharing services as well as selling advertising-free versions of the same technologies. Google has also developed an open source web browser and a mobile operating removed stop words Stop words is the name given to words which are filtered out prior to, or after, processing of natural language data . Hans Peter Luhn, one of the pioneers in information retrieval, is credited with coining the phrase and using the concept in his design. It is controlled by human input and not automated. This is sometimes seen as a negative such as "the" and "a" from its indexes for several years, but then re-introduced them, making certain types of precise search possible again.
The term "descriptor" was coined by Calvin Mooers in 1948.
The Simple Knowledge Organisation System Simple Knowledge Organisation Systems is a family of formal languages designed for representation of thesauri, classification schemes, taxonomies, subject-heading systems, or any other type of structured controlled vocabulary. SKOS is built upon RDF and RDFS, and its main objective is to enable easy publication of controlled structured language (SKOS) provides a way to express index terms with Resource Description Framework The Resource Description Framework is a family of World Wide Web Consortium (W3C) specifications originally designed as a metadata data model. It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources; using a variety of syntax formats for use in the context of Semantic Web The Semantic Web is an evolving development of the World Wide Web in which the meaning of information and services on the web is defined, making it possible for the web to understand and satisfy the requests of people and machines to use the web content. It derives from World Wide Web Consortium director Sir Tim Berners-Lee's vision of the Web as.
Examples
- Canadian Subject Headings
- Library of Congress Subject Headings The Library of Congress Subject Headings comprise a thesaurus (in the information technology sense) of subject headings, maintained by the United States Library of Congress, for use in bibliographic records. LC Subject Headings are an integral part of bibliographic control, which is the function by which libraries collect, organize and disseminate
- Medical Subject Headings Medical Subject Headings is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences; it can also serve as a thesaurus that facilitates searching. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed article database and by NLM's
See also
- Keyword cloud
- Keyword density Keyword density is the percentage of times a keyword or phrase appears on a web page compared to the total number of words on the page. In the context of search engine optimization keyword density can be used as a factor in determining whether a web page is relevant to a specified keyword or keyword phrase
- Keyword optimization It would not be a very wise decision to rush into search engine marketing without having a set of relevant keywords ready beforehand. Search engines are all about keywords. The web surfer type in their search in the form of keywords and the search engines show results analyzing the relevance of those keywords in the web world
- Keyword tracking For example – when searching for the word “home” in a search engine, web site www.home.com appears in place number 3 in search results. When searching for the phrase “my home”, web site www.home.com appears on location number 14, second page of results. When doing Search engine optimization for a web site, usually a list of keywords and
References
Svenonius, Elaine (2000). The Intellectual Foundation of Information Organization (1 ed.). The MIT Press. ISBN 0262194333.
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in the database To search the keyword anorexia for example go to the CENTRA search screen and click Keyword see below
