Punctuating Embedded Lists in Scholarly Documents
Lists are often used in academic and scientific writing to present information in a clear and orderly fashion for readers. Whether the material a scholarly author wants to communicate is short and relatively simple or long and extremely complicated, an effectively laid out list can increase the accessibility and impact of the material, which can also prove more interesting and memorable when presented in a well-organised list. Lists can be either embedded in the main body of an academic or scientific document, or displayed by being set off from the main text. In both cases punctuation that distinguishes the separate items and helps to clarify their relationship to each other is absolutely essential for a successful list.
Embedded lists follow the rules governing normal sentence structure and are particularly appropriate when the items are not excessively complex. In its simplest form, a list in running text that correctly completes a sentence requires no special punctuation and no numbers or letters to mark individual items, as in ‘She brought pens, pencils and paper’ and ‘Our study focussed on scribes, marginalia, and scripts.’ A comma can be used (as in the second example) or not (as in the first) before the conjunction ‘and’ that precedes the final item, but this should match the usage pattern for serial commas elsewhere in the document. Even if no serial comma is normally used, one may still be needed at times to avoid ambiguity when a compound item joined by a conjunction appears before the main conjunction in a list. In ‘She brought pens, blue and red ink, and pencils,’ for instance, the serial comma is necessary before the final ‘and’ to avoid the implication that the ‘pencils’ were also ‘blue and red.’
If the opening or introductory part of the sentence containing a list does not lead naturally into the list (with a verb or preposition, for instance), but forms an independent clause, a colon is normally used to introduce the list part of the sentence, as it is in the following example. ‘The paper was a team effort: David conducted the research, Emily analysed the data and Amanda drafted the text.’ If an embedded list is brief or informal, a dash (en rule or em rule) can be used instead of the colon, as in ‘She brought what we needed – pens, pencils and paper,’ but since the dash tends to imply an aside or afterthought rather than a main idea, a colon is the better choice in most cases. The two should certainly not be used together, with the dash following the colon, as they once were in scholarly prose.
When one (or more) of the items in an embedded list is especially long or contains internal commas, semicolons should be used instead of commas to separate the individual items. In such cases a semicolon should appear before the conjunction preceding the final item even if a serial comma is not normally used in the document. My next sentence provides an example, but embedded lists with this structure can be much longer and more complex. ‘The paper was a team effort, with everyone contributing their best: David had designed the methodology, so he conducted the research; Emily has taken several courses in statistics, so she analysed the data; and Amanda was working on her English degree, so she drafted the text.’
Finally, numbers or letters can be added to an embedded list to achieve a clearer division or to establish a hierarchy of order or importance. Arabic numerals (1,2,3 etc.) are better for this task than Roman numerals (I, II, III etc.), which can prove cumbersome in embedded lists and are best avoided unless publisher or instructor guidelines demand them. Letters are also appropriate, and usually appear in a lowercase format (a,b,c etc.), sometimes set in italic or bold font (though that aspect may not show up in my final example here). ‘Our study focussed on (1) scribes, (2) marginalia and (3) scripts” or ‘The paper was a team effort: (a) David had designed the methodology, so he conducted the research; (b) Emily has taken several courses in statistics, so she analysed the data; and (c) Amanda was working on her English degree, so she drafted the text.’ Whether numerals or letters are used, they should be enclosed in parentheses to clarify their function.
