General Uses of Parentheses in Academic Writing
Generally speaking, parentheses or round brackets tend to appear in scholarly writing more frequently than other brackets do. They have a number of specialised uses (in mathematical equations, for instance, or textual studies), but my focus here is on the uses of parentheses in a wide range of academic and scientific writing.
A common use of parentheses in the running text of scholarly prose is to enclose parenthetical material, specifically information that is not as closely related to the rest of the sentence as parenthetical material set off by commas, en rules or em rules is. ‘The original version of the text (written almost two decades earlier) did not contain this passage’ provides an example of correct usage.
Glosses, translations or bits of text in a foreign language can be enclosed within parentheses to provide more information for the reader, as is the case in ‘joie de vivre (joy of living)’ and ‘his words were “sed noli modo (but not now)”.’ Please note that when a title is translated in this way, any special font used on the title (such as italics) should be used for the translation as well.
Parentheses are often used to enclose explanations, alternative spellings and other supplementary information, as they are in the following examples: ‘the correct form is “programme” in British English (but “program” for computer software)’ and ‘much of the manuscript (late fifteenth century) appears to have been written by female scribes.’
Parentheses are also used when introducing and defining abbreviations of various kinds, as in ‘participants who completed Questionnaire 2 (Group Q2)’ and ‘American Medical Association (AMA).’ The full term usually comes first, but the order can be reversed – ‘AMA (American Medical Association)’ – which is handy for referencing because the abbreviation can be cited in the main text and then precede the full version in the reference list, which makes finding an abbreviated source straightforward for readers.
Dates, publication information, issue numbers and other aspects of full bibliographical references in both lists and notes are in some styles enclosed in parentheses. Parentheses are also used in running text to enclose in-text references in author–date systems of referencing: ‘(Bennett, 2006; Vanhoof, 2010).’
Parentheses often surround the item numbers in lists, particularly if a list is presented in running text as the following list is: ‘Four conditions were considered in the trial: (1) darkness inside, (2) darkness outside, (3) artificial lighting inside and (4) daylight outside.’ In such cases, a pair of parentheses enclosing each number is preferable to a single closing parenthesis after each number.
Tables and figures can contain a variety of information in parentheses, which are particularly effective for separating different measurements and kinds of data (such as number and percentage), even within the narrow column of a table: ‘34(50%)’ in one row, for example, ‘17(25%)’ in the next and ‘17(25%)’ in another.
Keep in mind when you are using parentheses that most parenthetical material needs to correspond with what has immediately preceded it in terms of both content and grammar. For instance, 34 participants and 50% of the sample are equivalent in my last example above, and ‘in that year (1996)’ is appropriate and correct, but ‘in that year (1996–1999)’ is not.
