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Controlled Vocabularies
A controlled vocabulary provides a way to organize knowledge for subsequent retrieval. Controlled vocabularies are used in subject indexing schemes, subject headings, thesauri, taxonomies and other knowledge organization systems. Controlled vocabulary schemes mandate the use of predefined, preferred terms that have been preselected by the designers of the schemes, in contrast to natural language vocabularies, which have no such restriction. In library and information science In library and information science, controlled vocabulary is a carefully selected list of words and phrases, which are used to tag units of information (document or work) so that they may be more easily retrieved by a search. Controlled vocabularies solve the problems of homographs, synonyms and polysemes by a bijection between concepts and preferred terms. In short, controlled vocabularies reduce unwanted ambiguity inherent in normal human languages where the same concept can be given different names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subject Indexing
Subject indexing is the act of describing or classifying a document A document is a writing, written, drawing, drawn, presented, or memorialized representation of thought, often the manifestation of nonfiction, non-fictional, as well as fictional, content. The word originates from the Latin ', which denotes ... by index terms, keywords, or other symbols in order to indicate what different documents are '' about'', to summarize their contents or to increase findability. In other words, it is about identifying and describing the '' subject'' of documents. 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 (such as books and articles) within a field of knowledge. Subject indexing is used in information retrieval especially to create bibliographic indexes to retrieve documents on a particular subject. Examples of academic indexing services are Zentralblatt MATH, Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library Of Congress Subject Heading
The Library of Congress Subject Headings (LCSH) comprise a thesaurus (in the information science sense, a controlled vocabulary) 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 documents. It was first published in 1898, a year after the publication of Library of Congress Classification (1897). The last print edition was published in 2016. Access to the continuously revised vocabulary is now available via subscription and free services. Subject headings are normally applied to every item within a library's collection and facilitate a user's access to items in the catalog that pertain to similar subject matter, in order to save time finding items of related subject matter. Only searching for items by 'title' or other descriptive fields, such as 'author' or 'publisher', would take mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
False Positives
A false positive is an error in binary classification in which a test result incorrectly indicates the presence of a condition (such as a disease when the disease is not present), while a false negative is the opposite error, where the test result incorrectly indicates the absence of a condition when it is actually present. These are the two kinds of errors in a binary test, in contrast to the two kinds of correct result (a and a ). They are also known in medicine as a false positive (or false negative) diagnosis, and in statistical classification as a false positive (or false negative) error. In statistical hypothesis testing, the analogous concepts are known as type I and type II errors, where a positive result corresponds to rejecting the null hypothesis, and a negative result corresponds to not rejecting the null hypothesis. The terms are often used interchangeably, but there are differences in detail and interpretation due to the differences between medical testing and st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relevance (Information Retrieval)
In information science and information retrieval, relevance denotes how well a retrieved document or set of documents meets the information need of the user. Relevance may include concerns such as timeliness, authority or novelty of the result. History The concern with the problem of finding relevant information dates back at least to the first publication of scientific journals in the 17th century. The formal study of relevance began in the 20th century with the study of what would later be called bibliometrics. In the 1930s and 1940s, S. C. Bradford used the term "relevant" to characterize articles relevant to a subject (cf., Bradford's law). In the 1950s, the first information retrieval systems emerged, and researchers noted the retrieval of irrelevant articles as a significant concern. In 1958, B. C. Vickery made the concept of relevance explicit in an address at the International Conference on Scientific Information. Since 1958, information scientists have explored and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Text Search
In text retrieval, full-text search refers to techniques for searching a single computer-stored document or a collection in a full-text database. Full-text search is distinguished from searches based on metadata or on parts of the original texts represented in databases (such as titles, abstracts, selected sections, or bibliographical references). In a full-text search, a search engine examines all of the words in every stored document as it tries to match search criteria (for example, text specified by a user). Full-text-searching techniques appeared in the 1960s, for example IBM STAIRS from 1969, and became common in online bibliographic databases in the 1990s. Many websites and application programs (such as word processing software) provide full-text-search capabilities. Some web search engines, such as the former AltaVista, employ full-text-search techniques, while others index only a portion of the web pages examined by their indexing systems. Indexing When dealing with a sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Language
A natural language or ordinary language is a language that occurs naturally in a human community by a process of use, repetition, and change. It can take different forms, typically either a spoken language or a sign language. Natural languages are distinguished from constructed and formal languages such as those used to program computers or to study logic. Defining natural language Natural languages include ones that are associated with linguistic prescriptivism or language regulation. ( Nonstandard dialects can be viewed as a wild type in comparison with standard languages.) An official language with a regulating academy such as Standard French, overseen by the , is classified as a natural language (e.g. in the field of natural language processing), as its prescriptive aspects do not make it constructed enough to be a constructed language or controlled enough to be a controlled natural language. Natural language are different from: * artificial and constructed la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metadata
Metadata (or metainformation) is "data that provides information about other data", but not the content of the data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive information about a resource. It is used for discovery and identification. It includes elements such as title, abstract, author, and keywords. * Structural metadata – metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters. It describes the types, versions, relationships, and other characteristics of digital materials. * Administrative metadata – the information to help manage a resource, like resource type, and permissions, and when and how it was created. * Reference metadata – the information about the contents and quality of Statistical data type, statistical data. * Statistical metadata – also called process data, may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Education Resources Information Center
The Education Resources Information Center (ERIC) is an online digital library of education research and information. ERIC is sponsored by the Institute of Education Sciences of the United States Department of Education. Description The mission of ERIC is to provide a comprehensive, easy-to-use, searchable, Internet-based bibliographic and full-text database of education research and information for educators, researchers, and the general public. Education research and information are essential to improving teaching, learning, and educational decision-making. ERIC provides access to 1.5 million bibliographic records (citations, abstracts, and other pertinent data) of journal articles and other education-related materials, with hundreds of new records added every week. A key component of ERIC is its collection of grey literature in education, which is largely available in full text in Adobe PDF format. Approximately one quarter of the complete ERIC Collection is available in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Art And Architecture Thesaurus
The Art & Architecture Thesaurus (AAT) is a controlled vocabulary used for describing items of art, architecture, and material culture. The AAT contains generic terms, such as "cathedral", but no proper names, such as "Cathedral of Notre Dame." The AAT is used by, among others, museums, art libraries, archives, Cataloging#Cataloging rules, catalogers, and researchers in art and art history. The AAT is a thesaurus in compliance with International Organization for Standardization, ISO and NISO standards including ISO 2788, ISO 25964 and ANSI/NISO Z39.19. The AAT is a structured vocabulary of 55,661 concepts (as of January 2020), including 131,000 terms, descriptions, bibliographic citations, and other information relating to fine art, architecture, decorative arts, archival materials, and material culture. History The AAT project began in the late 1970s in response to the gradual automation of records by art libraries, art journal indexing services, and catalogers of museum objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sears Subject Headings
Sears, Roebuck and Co., commonly known as Sears ( ), is an American chain of department stores and online retailer founded in 1892 by Richard Warren Sears and Alvah Curtis Roebuck and reincorporated in 1906 by Richard Sears and Julius Rosenwald, with what began as a mail-order catalog company migrating to opening retail locations in 1925, the first in Chicago. Through the 1980s, Sears was the largest retailer in the United States. In 2005, the company was bought by the management of the American big box discount chain Kmart, which upon completion of the merger, formed Sears Holdings. In 2018, it was the 31st-largest. After several years of declining sales, Sears' parent company filed for Chapter 11 bankruptcy on October 15, 2018. It announced on January 16, 2019, that it had won its bankruptcy auction, and that a reduced number of 425 stores would remain open, including 223 Sears stores. Sears was based in the Sears Tower in Chicago from 1973 until moving out to Hoffman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Library Of Medicine
The United States National Library of Medicine (NLM), operated by the United States federal government, is the world's largest medical library. Located in Bethesda, Maryland, the NLM is an institute within the National Institutes of Health. Its collections include more than seven million books, journals, technical reports, manuscripts, microfilms, photographs, and images on medicine and related sciences, including some of the world's oldest and rarest works. the acting director of the NLM was Stephen Sherry. History The precursor of the National Library of Medicine, established in 1836, was the Library of the Surgeon General's Office, a part of the office of the Surgeon General of the United States Army. The Armed Forces Institute of Pathology and its Medical Museum were founded in 1862 as the Army Medical Museum. Throughout their history the Library of the Surgeon General's Office and the Army Medical Museum often shared quarters. From 1866 to 1887, they were ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Subject Headings
Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing Academic journal, journal articles and books in the Life science, life sciences. It serves as a thesaurus of index terms 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 catalog of book holdings. MeSH is also used by ClinicalTrials.gov registry to classify which diseases are studied by trials registered in ClinicalTrials. MeSH was introduced in the 1960s, with the NLM's own index catalogue and the subject headings of the Quarterly Cumulative Index Medicus (1940 edition) as precursors. The yearly printed version of MeSH was discontinued in 2007; MeSH is now available only online. It can be browsed and downloaded free of charge through PubMed. Originally in English, MeSH has been translated into numerous other languages and allows retrieval of documents from differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
