Tips for writing abbreviations
- Define abbreviations at first mention: Abbreviations should be defined at first mention in each of the following sections in your paper: title, abstract, text, each figure/table legend. Abbreviations work well when you want to reduce the number of words to use. But an abbreviation that is well known in one field may not be common in another.
Example: We analyzed the results of the computational fluid dynamics (CFD) simulations to determine fluid flow and to detect cavitation in centrifugal pumps.
In the above example, the term CFD is fairly common in mechanical/civil engineering fields, but might not be clear to an interdisciplinary audience.As a best practice, once you have finished writing the entire manuscript, use the “Find” or equivalent function of your word processor to locate abbreviations and check if they are defined.
- Always consult the target journal’s guidelines on abbreviation usage:
Depending on their focus and target audience, many journals (either broad focus or narrow focus) provide a list of abbreviations that can be used without definition. For example, DNA and ANOVA are fairly common abbreviations that most journals will allow. However, while a mechanical engineering journal might allow the use of CFD without definition, it may not allow the use of FWHM (full-width-at-half-maximum).
Some journals ask that abbreviations be introduced only if the term is used 3 or more times in the text.
Some journals discourage the use of any abbreviations in the title and the abstract.
Terms like CFD are so common and unambiguous that they need not be defined.
- Make sure you use abbreviations that are standard in your field: In the physical sciences, we often use shortened forms for elements (e.g., Si, Cu, C, O, N) and measurement units (e.g., s, h, min, m, kg, K, J). It should be noted that these shortened forms need not be explicitly defined upon first use, but should always be indicated using the standard format (spelling as well as capitalization).
- Preferred styles for using abbreviations:
When using abbreviations, it is useful to remember that just because an abbreviation is written in capitals does not mean that the capitalization must be retained when the abbreviation is set out in full. Capitalization is generally reserved only for given names or proper nouns.
Example: FFT is fast Fourier transform—“Fourier” is a given name of a person, so it is capitalized, but the other terms can be retained in lowercase lettering.
Some terms are usually indicated by uppercase as well as lowercase letters. Such terms are provided by most journals under an accepted list of terms that need not be defined. When a manuscript also contains other abbreviations that are defined with the same letters, the lowercase format is preferred for the well-known terms, as the competing terms are generally represented by uppercase letters.
Examples: Alternating current (AC/ac), direct current (DC/dc), root mean square (RMS/rms), rotations/revolutions per minute (RPM/rpm).
These terms are acceptable in both uppercase as well as lowercase lettering. However, when there are other competing terms in the same manuscript, the priority of using uppercase lettering goes to the less common term [digital communication (DC) uses uppercase lettering and direct current (dc) uses lowercase letters].
- Be careful when using alphanumeric abbreviations: Many shortened forms are alphanumeric, and generally, there is a rationale behind these combinations. The numerals before/after the letters simply indicate a detail associated with a parameter. For example, a system may have different degrees of freedom depending on the number of independent variables (2-DoF, 6-DoF, n-DoF). Over time, the numerals become part of the names (2D, 3D). Appropriate combinations of letters and numerals are therefore chosen depending on the meanings that need to be conveyed.
Example 1: n-DoF (n degrees of freedom)
Here, “n” represents the number of independent parameters of the system.
- Use of Latin abbreviations: Scientific writing often uses a few Latin abbreviations, such as “e.g.”, “i.e.”, and “et al.” All of these are used in lowercase and the usage of period should be as per convention. Missing or misplacing a period is akin to misspelling for these abbreviations. Now let’s take a deeper look at these:
The abbreviation “e.g.” stands for exempli gratia, which means “for example” and “i.e.” stands for id est, meaning “that is.” These two abbreviations are always followed by a comma in American English (no comma is required in British English). When used inline, they are either spelled out or offset by commas. However, it is always appropriate to avoid mixing styles. In the examples below, both inline and parenthesized versions are presented in American English convention.
Examples:
- Some studies (e.g., Jenkins & Morgan, 2010) have supported this conclusion. Others—for example, Chang (2004)—disagreed.
- Some studies, e.g., Jenkins & Morgan (2010), have supported this conclusion. Others, e.g., Chang (2004), disagreed.
- Two types of defects (i.e., cracks and bends) were investigated for each alloy.
- Two types of defects, i.e., cracks and bends, were investigated for each alloy.
One of the trickiest abbreviations used in scientific writing is “et al.” as it is often misspelled or used incorrectly. This term stands for et alii, meaning “and others”. This abbreviation is used only to shorten lists of names, such as those in in-text citations or references, and can be used anywhere in the text so long as it is preceded by a name. Any punctuation before or after this term is determined by the formatting style alone. In the examples below, a name precedes the term and additional punctuation depends on formatting style (APA is used here).
Examples:
- Bjeg et al. (2016) show that the aspect ratio of the room determines whether the airflow is two- or three-dimensional.
- Previous reports (Bjeg et al., 2016) indicate that the aspect ratio of a room determines whether the airflow is two- or three-dimensional.
These requirements should be specifically noted and followed to achieve a concise, technically correct, and well-written manuscript.