Reference

For information on citing sources in Wikipedia, seeWikipedia:Citing sources.

Areferenceis a relationship betweenobjectsin which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said torefer tothe second object. It is called anamefor the second object. The next object, the one to which the first object refers, is called thereferentof the first object. A name is usually aphraseor expression, or some othersymbolic representation.Its referent may be anything – a material object, a person, an event, an activity, or an abstract concept.

References can take on many forms, including: a thought, a sensory perception that isaudible(onomatopoeia),visual(text),olfactory,or tactile,emotional state,relationship with other,spacetimecoordinates,symbolicorAlpha -numeric,a physical object, or an energy projection. In some cases, methods are used that intentionally hide the reference from some observers, as incryptography.

References feature in many spheres of human activity and knowledge, and the term adopts shades of meaning particular to the contexts in which it is used. Some of them are described in the sections below.

Etymology and meanings

The wordreferenceis derived fromMiddle Englishreferren,fromMiddle Frenchréférer,fromLatinreferre,"to carry back", formed from theprefixre- andferre,"to bear".A number of words derive from the same root, includingrefer,referee,referential,referent,referendum.

The verbrefer (to)and its derivatives may carry the sense of "connect to" or "link to", as in the meanings ofreferencedescribed in this article. Another sense is "consult"; this is reflected in such expressions asreference work,reference desk,job reference,etc.

Semantics

Further information:Sense and referenceandTheory of reference

Thetriangle of reference,from the influential bookThe Meaning of Meaning(1923) byC. K. OgdenandI. A. Richards

Insemantics,reference is generally construed as the relationships betweennounsorpronounsand objects that are named by them. Hence, theword"John" refers to the person John. The word "it" refers to some previously specified object. The object referred to is called thereferentof the word.Sometimes the word-object relation is called "denotation";the word denotes the object. The converse relation, the relation from object to word, is called"exemplification";the object exemplifies what the word denotes. In syntactic analysis, if a word refers to a previous word, the previous word is called the"antecedent".

Meaning

Gottlob Fregeargued that reference cannot be treated as identical withmeaning:"Hesperus"(an ancient Greek name for the evening star) and"Phosphorus"(an ancient Greek name for the morning star) both refer toVenus,but the astronomical fact that ' "Hesperus" is "Phosphorus" ' can still be informative, even if the "meanings" of "Hesperus" and "Phosphorus" are already known. This problem led Frege to distinguish between thesense and referenceof a word.

Linguistic sign

The very concept of thelinguistic signis the combination of content and expression, the former of which may refer entities in the world or refer more abstract concepts, e.g. thought. Certain parts of speech exist only to express reference, namelyanaphorasuch aspronouns.The subset of reflexives expresses co-reference of two participants in a sentence. These could be theagent(actor) and patient (acted on), as in "The man washed himself", the theme and recipient, as in "I showed Mary to herself", or various other possible combinations.

Computer science

Main article:Reference (computer science)

Incomputer science,referencesaredata typesthat refer to an object elsewhere in memory and are used to construct a wide variety ofdata structures,such aslinked lists.Generally, a reference is a value that enables a program to directly access the particular data item. Mostprogramming languagessupport some form of reference. For the specific type of reference used in theC++language, seereference (C++).

The notion of reference is also important in relationaldatabase theory;seereferential integrity.

Library and information sciences

See also:Reference workandReference desk

References to many types of printed matter may come in an electronic or machine-readable form. For books, there exists theISBNand for journal articles, theDigital object identifier (DOI)is gaining relevance. Information on theInternetmay be referred to by aUniform Resource Identifier (URI).

Psychology

In terms of mental processing, aself-referenceis used in psychology to establish identification with a mental state during self-analysis. This seeks to allow the individual to develop own frames of reference in a greater state of immediate awareness. However, it can also lead to circular reasoning, preventing evolution of thought.

According to Perceptual Control Theory (PCT), a reference condition is the state toward which a control system's output tends to alter a controlled quantity. The main proposition is that "All behavior is oriented all of the time around the control of certain quantities with respect to specific reference conditions."

Scholarship

In academics and scholarship, a reference orbibliographical referenceis a piece of information provided in afootnoteorbibliographyof awritten worksuch as a book, article, essay, report, oration or any othertexttype,specifying the written work of another person used in the creation of that text. A bibliographical reference mostly includes the full name of theauthor,the title of their work and the year of publication. The primary purpose of references is to allow readers to examine the sources of a text, either forvalidityor to learn more about the subject. Such items are often listed at the end of a work in a section markedReferencesorBibliography.

References are particularly important as for the use ofcitations,sincecopyingof material by another author without proper reference and / or without required permissions is consideredplagiarism,and may be tantamount tocopyright infringement,which can be subject tolegal proceedings.Areferencesection contains only those works indeed cited in the main text of a work. In contrast, abibliographicalsection often contains works not cited by the author, but used as background reading or listed as potentially useful to the reader.

Keeping adiaryallows an individual to use references for personal organization, whether or not anyone else understands the systems of reference used. However, scholars have studied methods of reference because of their key role in communication and co-operation betweendifferentpeople, and also because of misunderstandings that can arise. Modern academic study of bibliographical references has been developing since the 19th century.

Law

Inpatentlaw, a reference is a document that can be used to show the state of knowledge at a given time and that therefore may make aclaimedinventionobviousoranticipated.Examples of references are patents of any country, magazine articles,Ph.D.theses that are indexed and thus accessible to those interested in finding information about the subject matter, and to some extent Internet material that is similarly accessible.

Arts

Inart,a reference is an item from which a work is based. This may include:

• an existing artwork
• a reproduction (i.e., a photo)
• a directly observed object (e.g., a person)
• the artist's memory

Another example of reference issamplesof various musical works being incorporated into a new one.

See also

• Antecedent (grammar)
• Exemplification
• Generic antecedent
• Hyperlink
• Indexicality
• ISO 690
• Recommendation letter
• Semiotics,the study of signs which communicate meaning
• Signified and signifier
• Supposition theory,medieval European theories of reference

External links

• Reference– a multi-source encyclopedia search service, and language reference products provider
• "Reference Resources".Yahoo! Directory.
• References.net– a directory of multidisciplinary reference resources on the web
• Refmuseum– The online museum of references