In the information system, the tag is a keyword or term defined for a piece of information (such as an Internet bookmark, digital image, database record, or computer file). This kind of metadata helps describe an item and allows it to be found again by browsing or searching. Tags are generally selected informally and personally by the item maker or by the viewer, depending on the system, although they can also be selected from controlled vocabulary.
Tagging is popularized by Web 2.0-related websites and is an important feature of many Web 2.0 services. Now it's also part of other database systems, desktop apps, and operating systems.
Video Tag (metadata)
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People use tags to help classify, mark ownership, record boundaries, and show online identity. Tags can be words, images, or other identification. A similar example of a tag in the physical world is a marker of a museum object. People use textual keywords to classify information and distant objects before the computer. Computer-based search algorithms make use of these keywords as a quick way to explore recordings.
Tagging gained popularity due to the growth of social bookmarking, image sharing, and social networking websites. These sites allow users to create and manage labels (or "tags") that categorize content using simple keywords. Websites that include tags often display tag collections as tag clouds, as do some desktop apps. On websites that collect all users' tags, individual user tags can be useful for them and for the larger website user community.
The tagging system is sometimes classified into two types: top-down and from the bottom up . Top-down taxonomy is made by a group of authorized designers (sometimes in controlled vocabulary form), while bottom-up taxonomies (called folksonomies) are created by all users. The definition of "top down" and "bottom up" should not be confused with the difference between a single hierarchical tree structure (where there is one correct way to classify each item) versus multiple non-hierarchical sets (where there are many ways to classify an item); top-down and bottom-up taxonomic structures can be either hierarchical, non-hierarchical, or a combination of both. Some researchers and applications have experimented with combining hierarchical and non-hierarchical tagging to aid in information retrieval. Others combine top-down and bottom-up tagging, including in several large library catalogs (OPAC) such as WorldCat.
When other tags or taxonomies have more properties (or semantics) such as relationships and attributes, they form ontologies.
The metadata tags as described in this article should not be confused with the use of the word "tag" in some software to refer to automatically generated cross references; the last example is the tag table in Emacs and smart tags in Microsoft Office.
Maps Tag (metadata)
History
The use of keywords as part of the identification and the old classification system precedes the computer. Paper data storage devices, especially edge-curved cards, allowing classification and sorting with multiple criteria have been used before the 20th century, and the classification of facets has been used by libraries since the 1930s.
In the late 1970s and early 1980s, the Emacs Unix text editor offered a companion software program called Tag that could automatically create cross-reference tables called the tag table Emacs can be used to jump between function calls and the function's definition. The use of the word "tag" does not refer to the metadata tag, but it is the initial use of the word "tag" in the software to refer to the word index.
Online databases and initial websites use keyword tags as a way for publishers to help users find content. In the early days of the World Wide Web, the meta element keywords was used by web designers to tell the web search engine what a web page is, but this keyword is only visible in the source code of the webpage and can not be modified by the user.
In 1997, the collaborative portal of "Description of the Equator and Several ÃÆ'ËÅ"therLands" made by documenta X, Germany, uses the economic term Tag for fellow authors and guest authors on the Upload page. In "The Equator", the term Tag for user input is described as abstract literal or keyword to help the user. However, the user defines a single Tag , and does not share Tags at that point.
In 2003, the social bookmarking site Delicious provides a way for its users to add "tags" to their bookmarks (as a way to help find them later); Delicious also provides a viewable aggregate view of all users displaying certain tags. Within a few years, Flickr photo sharing sites allow users to add their own text tags to their respective images, building flexible and easy metadata that make images highly searchable. The success of Flickr and the influence of Deliver popularized the concept, and other social software websites - such as YouTube, Technorati, and Last.fm - also applied tagging. In 2005, the Atom web syndication standard provided a "category" element for entering subject categories into web feeds, and in 2007 Tim Bray proposed the "tag" URN.
Example
Inside the blog
Many blog systems (and other web content management systems) allow authors to add free form tags to posts, along with (or not) placing posts into pre-defined categories. For example, a post may show that it has been tagged with baseball and tickets . Each tag is usually a web link pointing to an index page listing all posts associated with that tag. Blogs may have a sidebar list of all the tags used on that blog, with each tag pointing to the index page. To re-classify a post, an author edits his or her tag list. All relationships between posts are automatically tracked and updated by the blog software; no need to relocate the page in a complex category hierarchy.
Inside the application software
Some desktop apps and web apps display their own tagging systems, such as email tagging in Gmail and Mozilla Thunderbird, tagging bookmarks in Firefox, audio tagging in iTunes or Winamp, and tagging photos in various apps. Some of these apps display tag collections as tag clouds.
Assigned to computer file
There are various systems for applying tags to files in the computer's file system. In Apple macOS, the operating system has allowed the user to assign some random tags as extended file attributes to files or folders since OS X 10.9 was released in 2013, and before that time open-source OpenMeta provides the same tagging functionality in macOS. Some semantic file systems that implement tags are available for the Linux kernel, including Tagsistant. Microsoft Windows allows users to set tags only on Microsoft Office documents and some types of image files.
Cross platform file marking standards include the Extensible Metadata Platform (XMP), an ISO standard for embedding metadata into popular image, video and document formats, such as JPEG and PDF, without damaging their readability by applications that do not support XMP. XMP largely replaces IP Interface Information IPTC before. Exif is a standard that defines the image and audio file formats used by digital cameras, including some metadata tags. TagSpaces is an open-source cross-platform app for tagging files; it inserts a tag into the filename.
For event
The official tag is the keyword adopted by events and conferences for participants to use in their web publications, such as blog posts, event photos, and presentation slides. The search engines can then index them to create relevant material related to the event that can be searched in a uniform way. In this case, tags are part of a controlled vocabulary.
In research
Researchers can work with many collections of goods (eg press citation, bibliography, images) in digital form. If he wants to associate each of them with a small number of themes (eg book chapters, or sub-themes of the whole subject), then a bunch of tags for this theme can be attached to each item in a larger collection. In this way, the free form classification allows the author to manage what is expressed as the amount of heavy information.
Special types
The triple or machine tag uses a special syntax to specify additional semantic information about the tag, making it easier or more meaningful for interpretation by a computer program. Triple tags consist of three parts: namespace, predicate, and value. For example, geo: long = 50.123456 is the tag for geographical longitude coordinates whose value is 50.123456. This three structure is similar to the Resource Framework model for information.
The first triple tag format was created for geolicious in November 2004, to map Delicious bookmarks, and gained wider acceptance after being adopted by Mappr and GeoBloggers to map Flickr photos. In January 2007, Aaron Straup Cope on Flickr introduced the term machine tag as an alternative name for the triple tag, adding some intentional questions and answers, syntax, and usage.
Specific metadata for geographic identification known as geotagging ; machine tags are also used for other purposes, such as identifying photos taken on a particular event or naming a species using binomial nomenclature.
Hashtag is a type of metadata tag marked with the prefix # , sometimes known as the "hash" symbol. This form of tagging is used on microblogging and social networking services such as Twitter, Facebook, Google, VK, and Instagram.
The knowledge tag is a type of meta information that describes or defines some aspect of a piece of information (such as a document, a digital image, a database table, or a web page). Knowledge tags are more than traditional non-hierarchical keywords or terms; they are metadata types that capture knowledge in the form of descriptions, categorizations, classifications, semantics, comments, notes, annotations, hyperdata, hyperlinks, or references collected in tag profiles (sort of ontologies). This tag profile refers to a source of information that resides in a distributed and often heterogeneous storage warehouse.
The knowledge tag is part of a knowledge management discipline that utilizes Enterprise 2.0 methodology for users to capture the insights, expertise, attributes, dependencies, or relationships associated with the data source. Different types of knowledge can be captured in the tag of knowledge, including factual knowledge (found in books and data), conceptual knowledge (found in perspectives and concepts), expectation knowledge (required for making judgments and hypotheses), and methodological knowledge (derived from reasons and strategy). These forms of knowledge often exist outside the data itself and come from personal experience, insight, or expertise. The knowledge tag is considered an extension of the information itself that adds value, context, and meaning to information. The tag of knowledge is valuable for maintaining the organizational intelligence that is often lost due to rotation, to sharing knowledge stored in the minds of individuals who are usually isolated and unaffected by the organization, and for linking knowledge that is often lost or disconnected from information sources.
Advantages and disadvantages
In a custom tagging system, there is no explicit information about the meaning or semantics of each tag, and users can apply new tags to an item as easy as applying an older tag. Hierarchical classification systems can be slow to change, and rooted in the culture and era that created them; Conversely, tagging flexibility allows users to classify their collection of items in ways they find useful, but personalized terms can present challenges when searching and browsing.
When a user can freely select a tag (make folksonomy, as opposed to choosing a term from a controlled vocabulary), the resulting metadata may include homonyms (same tags used with different meanings) and synonyms (multiple tags for the same concept), which may causing an inappropriate relationship between the item and inefficient search for information about the subject. For example, the "orange" tag can refer to a fruit or a color, and items related to the Linux kernel version can be marked "Linux", "kernel", "Penguin", "software", or various other terms. Users can also choose different tags inflection of words (such as singular and plural), which may contribute to navigation difficulties if the system does not include stem tags when searching or browsing. Large-scale Folksonomies overcome some tagging issues, where users of tagging systems tend to pay attention to the current use of "tag terms" in this system, and thus use existing tags to easily establish connections to related items. In this way, folksonomies can collectively develop partial labeling partial conventions.
Dynamic system dynamics
Regardless of the lack of control, research has shown that a simple form of shared vocabulary appears in social bookmarking systems. Collaborative marking shows a complex form of system dynamics (or self-regulating dynamics). Thus, even if no central-controlled vocabulary limits the actions of individual users, the tag distribution coalesces over time into a stable distribution of laws of power. After such a stable distribution, a simple economic vocabulary can be extracted by examining the correlations formed between different tags. In addition, research has suggested that it is easier for machine learning algorithms to study the tag semantics when users tag "verbosely" - when they annotate resources with many freely related descriptive keywords.
Spamming
The publicly tagging system is also open to flag spam, where people use too many unrelated tags or tags into an item (such as a YouTube video) to attract viewers. This harassment may be reduced using human identification or spam item statistics. The number of allowed tags can also be limited to reduce spam.
Syntax
Some tagging systems provide a text box for entering tags, so to be able to encrypt strings, separators must be used. Two popular separators are spaces and commas. To enable the use of a separator in tags, the system may allow higher level separators (such as quotation marks) or escape characters. The system can avoid using separators by allowing only one tag to be added to each input widget at a time, although this makes adding multiple tags more time consuming.
The syntax for use in HTML is to use a rel-tag microformat that uses the rel attribute with the "tag" value (eg, rel = "tag" ) to indicate that a linked-to page serves as a tag for the current context.
See also
References
Source of the article : Wikipedia
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