5.5.2 Using Lists Effectively

Lists separate items in a structured form to highlight and often to arrange them in a hierarchy while emphasising each one, and can be especially effective for presenting complex, detailed and/or multilayered material, so you may well want or need to use lists in your thesis. Lists are only as effective as they are clear, however, so they must be formatted and written in appropriate ways. There are two basic kinds of lists: embedded lists that are run into the main text and displayed lists that are set vertically down the page. Embedded lists follow the rules governing normal sentence structure and are well suited to brief lists in which 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: for example, ‘She brought books, articles and paper’ and ‘My thesis focuses on medieval manuscripts, marginalia, and readership.’ A serial comma can be used (as in the second example) or not (as in the first) before the conjunction that precedes the final item depending on the usage in other sentences in the thesis (for more information on using commas, see Section 5.6.1 below).

If no serial comma is normally used, one may still be needed to avoid ambiguity when a compound item joined by a conjunction appears before the main conjunction in a list: in ‘They brought root beer, vanilla and chocolate ice cream, and cookies,’ for instance, the serial comma is necessary before the final ‘and’ to avoid the implication that the ‘cookies,’ too, were ‘vanilla and chocolate.’ Only items that share a valid syntactical relationship with the introductory part of a sentence should be linked with commas and a final conjunction in this way: for example, ‘The thesis must be well written, thoroughly proofread and use the serial comma consistently’ is poorer style than ‘The thesis must be well written and thoroughly proofread, and use the serial comma consistently’ because the third item (use the serial comma consistently) does not correctly follow, grammatically speaking, the introductory phrase (the thesis must be).

When the opening or introductory part of a 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 in the following example. ‘The potluck was a great success: Allan made lasagne, Mary brought fresh vegetables from her garden and Shea bought the wine’ (for more information on using colons, see Section 5.6.1). When introducing a list, ‘follow,’ ‘as follows’ or ‘the following’ often appears before the colon (‘The following topics are discussed: manuscripts, marginalia and readership’ or ‘The topics discussed are as follows: manuscripts, marginalia and readership’). If an embedded list is brief and/or informal, a dash (en rule or em rule, on which see Section 5.6.4) can be used instead of the colon (Three topics were discussed – manuscripts, marginalia and readership), but since a dash tends to imply an aside or afterthought rather than a main idea, a colon is the better choice in most cases, and the two should not be used together (:–) to introduce a list. If more definitive or clearer separation is required in an embedded list, numerals (Arabic, not Roman, which tend to be too cumbersome for embedded lists) or letters (usually lowercase) enclosed in parentheses and sometimes set in italic (more rarely bold) font can be used: ‘Adam made three important contributions to the picnic: (1) beer and soft drinks, (2) lasagne and garlic bread and (3) cookies and pies’ or ‘Adam made three important contributions to the picnic: (a) beer and soft drinks, (b) lasagne and garlic bread, and (c) cookies and pies.’

In some cases, one (or more) of the items in an embedded list is especially long and complex and/or contains internal commas. If any of the embedded lists you include in your thesis contain such items, you should use semicolons instead of commas to separate the individual items, and a semicolon should appear before the conjunction that precedes the final item even if you do not normally use a serial comma in your thesis: ‘Several people brought homemade products: Shea made two types of wine, red and white, and her husband brought his home-brewed beer; Mary made a salad with the fresh vegetables from her garden, baked a pie with the apples from her tree and picked flowers for the table; and Adam not only made lasagne and garlic bread, but also baked cookies’ (see also the discussion of semicolons in Section 5.6.1). Numbers or letters can easily be added to such a list for clearer division or to define a hierarchy of order or importance. In all cases, the items in embedded lists should be as consistent as possible in phrasing and structure, so that the list, like any other well-formed English sentence, is syntactically balanced, grammatically correct and complete. For example, if the first item begins with a noun followed by a verb and a past participle (e.g., ‘marginalia is abbreviated’), it is best not to word the second item with a present participle followed by a noun (e.g., ‘abbreviating marginalia’); instead, design and adjust your wording so that every item in your list uses a similar structure.

The grammatical balance required in an embedded list should also be observed in a displayed list, whether the list forms a single sentence or comprises many sentences. In most cases, single-sentence lists should be embedded instead of displayed, but since the purpose of displayed lists is to separate and emphasise material so that it can be easily found, consulted and understood, if such emphasis is required for a single-sentence list, a displayed format is appropriate.

When a displayed list forms a single sentence, each item should open with a lowercase letter, the individual items should be separated by commas or semicolons (depending on the length and complexity of each item) and the sentence should close with a full stop after the final item, but the conjunction that normally precedes the final item in embedded lists is omitted in displayed lists, as in the following example. ‘Adam’s contributions to the picnic included

• beer and soft drinks,
• lasagne and garlic bread,
• cookies and pies.’

The bullets are not strictly necessary – the three items could appear flush left – and numerals or (less often) letters could be used instead of the bullets to emphasise a hierarchy among the items. In a displayed list, where there is more room and clarity than in an embedded list, Roman instead of Arabic numerals can be used, but Arabic numerals are still the most common and acceptable choice. Sometimes such lists are slightly indented – if you have used numbers or bullets, for instance, Word will add indentation automatically, as it has in the displayed lists in this and the following two paragraphs – and occasionally displayed lists appear in a slightly smaller font than the main text of the thesis, though there is no need for this beyond saving a little space, and I have not used that format here.

Displayed lists tend to be introduced by an independent clause or complete sentence, followed by a colon or (less frequently) a full stop, as the next example shows. ‘Adam made three important contributions to the picnic:

1. beer and soft drinks
2. lasagne and garlic bread
3. cookies and pies’

When the items are short – single words, phrases or sentence fragments – as they are in the example above, each can begin with a lowercase letter. If numbers are used, a full stop usually follows each number, and the first letter of each item is sometimes capitalised. Commas or semicolons separating the items and a final full stop are not required when a list is introduced by an independent clause or a complete sentence, though they are also not strictly incorrect if the list with its introductory independent clause forms a single complete sentence, so in the example above, a comma could follow each of the first two items and a final stop could follow the third item.

For lists of items that are longer and more complex, with each of them forming one or more complete sentences, a displayed rather than an embedded format should be used, and whether numbers, bullets or no such markers are included, each item should begin with a capital and close with a full stop, as in the following example. ‘The picnic was a culinary success, with several people bringing homemade products:

• Adam contributed more than one course by bringing beer and soft drinks, making lasagne and garlic bread and baking both cookies and pies.
• Shea made two types of wine – red and white – and her husband brought his home-brewed beer.
• Mary made a salad with the fresh vegetables from her garden, baked a pie with the apples from her tree and picked flowers for the table.
• Allan not only made sandwiches of various kinds, but also built a picnic table for the occasion.’

With the automatic indentation provided for bulleted and numbered lists in Word, it is clear where one item ends and the next begins, but if no indentation is used, lines that run over within a single item can be indented slightly (using hanging indentation) to clarify the separation, or a little extra space can be added between the items.

In some instances, lists must be displayed vertically because the items are very long, but no special typographical prominence is necessary, so a simple paragraph format can be used after the list is introduced, with each paragraph numbered but otherwise like other paragraphs in the thesis, whether that means indentation of the first line of each paragraph or spacing between the paragraphs. Occasionally, however, lists are far more complex than any of the examples I have provided so far, featuring several levels or subdivisions. Indentation increasing slightly with each level can be used to distinguish the levels in such lists and, if the list is not too complicated, indentation of this kind is sometimes enough to make the level in which each item belongs clear to the reader, but complex subdivided lists are usually marked by a system of numerals (both Roman and Arabic if necessary), letters (both uppercase and lowercase if needed), parentheses (and perhaps square brackets) and italics (occasionally bold as well if a third font is required) to provide each level with distinctive qualities. There are no set rules for the order of such elements, so the method of labelling tends to vary from author to author; consistency for similar lists within a thesis is ideal, but different lists may require different treatment, so some flexibility is often necessary. Possible orders might include ‘1. (i) (a),’ ‘1. a. (i) (a),’ ‘I. A. 1. a. (i) (a)’ or any other combination that is logical, consistent and effective: see the Chicago Manual of Style (2003, p.275) for an example of a list with seven levels of differentiation.

Lists of all kinds provide an extremely effective means of presenting information, whether straightforward or complex, in an immediately accessible format, but the lists you use in your thesis can only do what they are intended to do if they are introduced in ways that explain both their function and content and create smooth and logical transitions between your normal prose and the lists. If, for instance, you are exploring the effectiveness of domestic robots as assistants for elderly people who live in apartments, an appropriate introduction to a list of the tasks considered might be: ‘In this study, I explore the effectiveness of three different domestic robots in performing for elderly apartment dwellers the following five household tasks: (1) grocery shopping, (2) preparing meals, (3) taking out the trash, (4) vacuuming and (5) dusting.’ The argument should continue equally smoothly in the following sentence with a discussion or elaboration of the five tasks or perhaps by listing and discussing the three different robots or providing details about the elderly participants: in the first case, the paragraph above the list could simply continue, but in the second or third, a new paragraph would probably be more appropriate. Because lists are more visually accessible than many other parts of a thesis, readers tend to return to lists when necessary to check definitions, categories, explanations and any other information included there, so it is essential that all terminology, abbreviations, data and other material in a list are accurate and use the exact same styles and forms as are used in the main discussion and other parts of the thesis. You want a confused reader to find clarity and resolution in your lists, not further confusion.

There are certain kinds of lists that have become so conventional in academic and scientific writing that no prose introduction to them is necessary. The footnotes that appear at the bottom of tables to list abbreviations and their definitions or probability values are good examples (see Section 4.4.1), and so are parenthetical author–date references (see Section 7.2.1). In both cases, semicolons are used to separate the individual items: for example, ‘ANOVA = analysis of variance; CI = confidence interval; ES = effect size’ is an effective table footnote and ‘(Adams, 2009; Brentwood, 2006; Jones, 2009; Putter, 2005)’ is a standard cluster of parenthetical author–date references. In many lists of this kind, an alphabetical arrangement (such as that I have just used in the two examples I provided) is traditional or required, and the same is the case when displayed lists such as abbreviation lists and reference lists (or bibliographies) feature a heading or title:

Abbreviations            

ANOVA: Analysis of variance

CI: Confidence interval

ES: Effect size

Notice that the first letter of each definition in this example is capitalised, and any additional main words may be as well (e.g., ‘Analysis of Variance’), and that the ‘=’ sign often used between an abbreviation and its definition in a table footnote is better as a colon in a displayed list, though colons can also be used for in-note lists. Alternate arrangements include chronological instead of alphabetical order for parenthetical author–date references, numerical order for lists of tables or figures and reference lists that accompany numerical in-text references and order of importance for lists of contributing authors and possible reviewers.

PRS Tip: The proofreaders at PRS read a lot of academic and scientific writing in a wide variety of disciplines and fields, so they have encountered and helped improve a wide variety of approaches to constructing paragraphs and lists. As readers who need to understand the texts before them both quickly and thoroughly, they can attest to just how vital the logical development of thoughtful paragraphs, the clear explanation of transitions and the effective presentation of lists are to your readers’ understanding of your research and argument. Noticing when aspects of scholarly writing are not presenting material clearly or are in fact preventing readers from understanding your meaning is precisely what PRS proofreaders do, so they can offer suggestions and corrections to help you produce logically developed paragraphs and effectively presented lists that not only look good on the page, but also feature smooth transitions and communicate your specific intentions and overall argument successfully to your readers.