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Citation generally is the means of attributing or linking particular material (facts, ideas, quotations, figures, etc.) to the source from which they are taken. Used particularly, "citation" – or "citations" in the aggregate – refers to individual instances of citation. These terms are sometimes distinguished from "referencing" and "references", but commonly used interchangeably with them.
Citations have two parts: the basic reference, which identifies the source, or "work", from which the material came, and the specific reference (or specification), giving the specific location within the work, such as the page number or section. (See WP:FULLCITE.)
The world is a big place. To aid in finding a source, and identifying it as the correct source, it is customary and expected to provide the fullest possible bibliographic details (the "facts of publication"). This includes at the least the author, possibly other authors and editors, as well as the title, publisher, date, etc., on down to cataloging codes (such as ISBN, DOI, PMID, OCLC, etc.) and even URLs. The term "full reference" (or "full citation") implies the inclusion of all this information.
In the simplest, most direct, and most naive form of citation all of the bibliographic details could be included in the text, in narrative format:
1: ... as shown by Robert Smith on page 123 in his book Big Book, published in 1988 by Cambridge University Press, with ISBN ....
Such usage is rarely seen, as that mass of bibliographic details impedes the flow of the idea being communicated. Some improvement can be had by setting off the entire reference in parentheses:
2: ... as shown by Robert Smith (page 123 in his book Big Book, published in ...) ....
At this point the advantages of a terser format are readily appreciated:
3: ... as shown by Smith (p. 123, Big Book, 1988, 978-xxxxxxx ...) ....
Even in a condensed format, bibliographic details in the text remain a substantial distraction, especially as the reader (or editor) may not be quite ready to use them to chase down the source. Wherefore various systems have been devised to move the reference out of the text, while maintaining linkage to the material requiring citation. The oldest of these are various "note" systems, such as the classic footnotes used in books. Here the reference is placed at the foot (bottom) of the page, with the location of the reference shown by a raised symbol or number:
4: ... usually the sky is blue,* but sometimes it is red‡ .... * Robert Smith, Big Book, .... ‡ Tom Brown, Another Book, ....
The raised asterisk is understood to mean "see the note at the foot of the page". With more than one footnote additional symbols are used to indicate which footnote.
Notes can also be collected at the end of the article, chapter, or book, as endnotes. The content of the notes are essentially the same, differing only in the location, and the means of linking them to the text. Such notes are typically numbered, the numbers replacing the symbols used above. (Other systems have been used. E.g.: using only an asterisk in the text, and the proper note identified by page number and a few words of the text.)
If the footnotes are moved to the end of the chapter or article (making them end notes), and the raised symbols replaced by raised numbers (and placed between square brackets to distinguish them from exponents), we get the system most frequently seen at Wikipedia:
5: ... usually the sky is blue,[1] but sometimes it is red[2] ....
Notes: 1 Robert Smith, Big Book, .... 2 Tom Brown, Another Book, ....
In Wikipedia usage (there being no pages as such) what are commonly called "footnotes" are usually placed at the end of the article, making them, strictly speaking, endnotes. However, in general Wikipedia usage "notes", "footnotes", and "endnotes" are used as equivalents.
Note: notes ("foot" or otherwise) are not references. This is confusing because notes are created using the <ref> and </ref> tags, where "ref" is derived from "reference". But the notes so created are only containers. These should not be confused with their content, which can contain comments or other text as well as references. References (citations) can be found in several places (in the text, "parenthetically" in the text, in foot notes, and in end notes); notes often contain references or citations, but often not. Again: notes are only containers, which should be distinguished from their content.
When a source is cited more than once it can be tedious to repeat all of the bibliographic details. A sensible practice, and indeed, the standard practice that has developed in two centuries of publishing, is to give the full reference only once (usually on the first citation). Subsequent citations use a shortened (or short) reference that refers back to the full reference. (The cryptic ibid., loc. cit., and op. cit. are ways of pointing to the proper reference – but not on Wikipedia!)
One of the drawbacks of a strict footnote system (and of notes created using the <ref> tags) is that the full references are scattered through out the work, and troublesome to find. To a lesser extent this is also true of endnotes, and in neither system is the complete list of sources readily examined. This has led to the common practice of collecting all of the full references in single reference list, usually in a section variously called "References", "Works cited", "Bibliography", or similar, alphabetized by the last name of the author.
It should be noted that just as the notes generated by the <ref> tags are not references, neither do the collected notes displayed by the {{reflist}} template (or similar templates) in a "Notes" section constitute a reference list. While full references in bibliographic format may be put into notes, this is not a suitable way of creating a reference list: the references cannot be alphabetized, notes with other material will intrude, and having references scattered through the article makes them harder to maintain and clutters the article text in edit mode. The best way of creating a reference list is to collect the references in a separate section (such as "References"). Each actual citation then no longer needs to provide the full bibliographic details: it simply gives a short reference with enough information (such as the author's last name and date of the work) to identify the full reference in the reference list, plus the specification. E.g.:
6: ... it has been shown (Smith, 1988, p. 123) that ....
References: * Smith, Robert (1988), Big Book ....
Because shortened citations in this style are so compact they are frequently used in the text, often "parenthetically", and so this style is often called "parenthetical referencing". However, it should be recalled that any kind of reference can be put into parentheses, as was seen in example #2 above. Shortened citations are not limited to using the author's name and date (the "author-date" system), but can use any suitable means of identifying the proper reference, including abbreviated title, or even acronyms. E.g., the work titled Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (with scores of authors and editors) is conveniently referred to as "IPCC AR4 WG1".
Some editors object to having even a shortened reference in the text (parenthetically or not). No problem! Shortened references are perfectly compatible with notes. E.g.:
7: ... it has been shown1 that ....
Notes: 1 Smith, 1988, p. 123.
References: * Smith, Robert (1988), Big Book ....
Exactly identical with the previous citation, except only that the shortened citation has been moved from the text to a note. The prior example is "parenthetical" because the citation is set off in parentheses: this example, having the citation set off in a note, is ... notical? At any rate, the use of "parenthetical" as synonymous with "author-date" is incorrect, and unfortunate in confusing what is basically a simple matter; such use should be avoided, even rejected. Also incorrect is the widespread misconception that use of the author-date method (of linking the basic reference of a citation to the full reference) is incompatible or antithetical to the use of any note system. As just seen in the example above: use of shortened citations in author-date form (or any similar form) is perfectly compatible with notes.
One of the fine features of the Wikimedia software is the ability to hyperlink shortened references (whether they use author-date, short titles, or acronyms) to the full reference, as shown here:
8: ... it has been shown1 that ... also2 ... and later confirmed3 ....
Notes: 1 Smith 1988, p. 123. 2 Smith 1988, p. 136. See also Brown 2004, pp. 206–214. 3 IPCC AR4 WG1 2007, Summary, p. 18
References:
* Brown, Tom (2004), Another Book ....
* IPCC AR4 WG1 (2007), Climate Change 2007 ...{{citation}}
: CS1 maint: numeric names: authors list (link)
* Smith, Robert (1988), Big Book ....
This is very easily done using one of the {{Harv}} templates. The actual code for the first link in the example above is: {{Harvnb|Smith|1988|p=123}} . Although the style of referencing known as "Harvard" is restricted to author-date style shortened references in parentheses in the text, the Wikipedia "Harv" templates are not so limited. As shown here they are quite suitable for use without parentheses, and in notes, and are readily adapted for tags other than author-date. (Also shown here: multiple citation of the same reference, use of a single footnote for multiple citations; use of an acronym for "author"; reference list in alphabetical order.)
Independently of the general methods of citation as described above, many citation styles have been developed, differing mainly in the formating of the citation. Though the differences (involving arcane issues of order of elements, capitalization, punctuation, and such) are often obscure, they often have passionate adherents, wherefore Wikipedia has no official or prescribed citation style. However, citation should be done consistently within each article. If an article has a particular style and method of citation any subsequent work should be consistent with that style and method, unless there is consensus to change it. (See WP:Citing sources#Variation in citation methods.)
The easiest and most reliable way to ensure consistent formatting of a reference (citation) is to use one of the standardized citation templates, such as: {{citation}}, {{cite}}, or {{vcite}}. Use of a citation template ensures correct (and automatic) formatting, enables collection of metadata, and can automatically create anchors for use with Harv templates. For an introduction to the perplexing multitude of citation methods available on Wikipedia see WP:Citation templates, or see the Resources below.
Summary:
edit- Citation is the means of attributing or linking particular material (facts, ideas, quotations, figures, etc.) to the source from which they are taken.
- A full citation consists of a basic reference to the work cited, and a specification to the specific locations (e.g., page numbers) within the work.
- Every work cited should have a full reference with full bibliographic details to aid in finding the work. These are conveniently collected in a single reference list, which can be alphabetized, is easier to maintain, and reduces clutter in the article text.
- Citations can be placed in various locations: in the text, in parentheses in the text, in a footnote, in an endnote.
- Notes are not references, they are places where references/citations may be placed.
- The full reference to a source need be given only once; subsequent citations can use a shortened reference that refers to the full reference. This referral can be done in various ways; use of the last name of the author (or authors) and date of publication as the basic reference is common and convenient.
- Generation of short references (citations) with hyperlinks to the full reference is readily done using the {{Harv}} family of templates.
- Use of citation templates avoids problems with formatting style.
- Citation format and method should be consistent within an article. Do not change an established format or method without the consensus of the other editors.
Resources
edit[This section needs expansion, and commentary to guide bewildered editors.]
For a comprehensive list of citation tools and documentation available on Wikipedia see: