Use plenty of paragraphsClear writing: paragraphs, headings and lists
Paragraphs, headings and lists are part of the ‘route map’ that allows readers to find their way around your document. Once you have a clear structure in your mind (as described in Chapter 29), you need to make that structure clear to the reader by laying it out on paper.
Here are some tips to help you do this.
Use plenty of paragraphs
Paragraphs are used to:
• group related thoughts
• provide visual relief.
Too many scientific papers are so mean in their use of paragraphs that you cannot see where one group of thoughts stops and the next one begins. There is no good reason for this – when you start a new topic, you should always start a new paragraph.
Do not be afraid of short paragraphs
If your paragraph includes more than five to seven sentences, ask yourself whether it contains more than one group of ideas. The chances are that it does. Could it be more effectively split into two? Do not worry if you end up with two- or three-sentence paragraphs. There is nothing wrong with short paragraphs – not every train of thought can be extended into several sentences.
One-sentence paragraphs are not wrong – but use them sparingly
Contrary to what you may have been taught at school, there is nothing grammatically wrong with a one-sentence paragraph. If you have only one thing to say on a particular topic, you can say it in a one-sentence paragraph.
But such paragraphs do draw attention to themselves.
So you should use one-sentence paragraphs only occasionally, for ideas that deserve emphasis. For example, the last paragraph of your paper might be a one-sentence conclusion, if that is all you have to say. One-sentence paragraphs are also useful for lists and instructions, where you want every point to stand out clearly and carry equal weight. However, if your one-sentence paragraph contains only a minor idea, you might like to merge it with an adjacent paragraph.
Use topic sentences to introduce paragraphs
It is very helpful to readers if the first sentence in the paragraph gives some idea of where the paragraph is going. For example, you might say:
Wound healing consists of three distinct phases. [topic sentence] First, an acute inflammatory phase occurs. Next, collagen synthesis repairs the wound. Finally, remodelling restores the skin’s structural integrity.
As you can see, starting with ‘the bottom line’ is much more effective than writing the paragraph the other way round:
Wounding is followed by an acute inflammatory phase. Next, collagen synthesis repairs the wound. Finally, remodelling processes restore the skin’s structural integrity. Thus, there are three phases to wound healing.
Break up long documents with headings …
In a scientific paper, the main headings will be dictated by the IMRAD format (introduction, methods, results and discussion). In other kinds of scientific writing (e.g. review articles) you will have a more-or-less free hand with the headings, so do not be afraid to use them generously to help readers find their way around the document.
… And subheadings
Under your main headings, you can use subheadings. These are appropriate in most kinds of scientific writing – even in letters or memos. In original research papers, most journals will let you use subheadings within the main sections. They can be very helpful to readers, especially within long methods and results sections. You may be able to match up the methods subheadings with the results subheadings.
But do not use too many levels of heading
It may be tempting, especially in a long and complex document, to use multiple levels of heading – right down to sub-sub-sub-subheadings. But this can be confusing for the reader – not to mention the writer. Usually, three levels of heading will be enough – the title or chapter heading, section headings and subheadings. If you really feel you need additional levels of headings, do not forget that you can use bulleted lists, and emboldened keywords at the beginning of sentences.
Only use numbered headings if there is a good reason
Some types of document, for example, a thesis or a drug regulatory report, may have a statutory requirement for numbered headings (1.0, 1.4, 1.3.8 and so on). If so, you must comply. However, when considering introducing numbered headings into other types of document (e.g. a book or manual), ask yourself if they are really needed. Are you going to have cross-references from one section to another? Are you going to refer to the numbered sections in the index? If readers do not need the numbers to navigate the document, do not put them in. You will only be making extra work for yourself when you add new sections. If you do decide to use numbered headings, your word-processing software will be able to place them in a table of contents and allow you to hyperlink statements to appropriate sections.
Match the style of your headings to the tone of the document
Formal scientific papers and reports will require formal headings – Methods, Results and so on. Subheadings will need to be brief and objective, e.g. Animal studies, Pharmacokinetics. In other kinds of scientific writing, e.g. a magazine article, you may decide to use main headings or subheadings that actually summarise what is in the text, e.g. Colon cancer – the silent killer or Six simple ways to cut computer costs. In very informal writing, particularly news articles or press releases, you may decide to use headings simply to attract attention, e.g. “It’s a jungle out there,” says Professor Smith.
Use lists wherever they help readers and are allowed by the journal
In formal journal articles you may be able to use numbered lists. For example, you could list the steps in a procedure. In some journals, and in less formal scientific writing (for example, a magazine article), you may also be able to use bullet-point lists. We have used lots of bullet-point lists in this book.
Arrange items in lists in logical order
When you give a list, readers will assume that there is some logic in its order. If you list items in random order you will be confusing the reader. So think carefully about the order of items in your list. Often, the best way is to list items in order of importance, or you may want to list them in chronological or hierarchical order.
Use parallel structure in lists where appropriate
If each item in the list contains several kinds of information, it is appropriate to arrange them in the same order each time. A parallel structure of this kind will help readers to find their way around the list. For example:
Wound healing consists of three phases:
1. The acute inflammatory phase occurs over the first few days. Neutrophils and macrophages migrate into the wound.
2. The collagen synthesis phase lasts for several weeks. Fibroblasts from the surrounding dermis migrate into the wound, synthesising new collagen.
3. The modelling phase lasts many months. Collagen cross-linking, collagenolysis and collagen synthesis occur simultaneously, strengthening the wound.
Be consistent about capitals and full stops in lists
Different publications have their own formats for lists. In draft manuscripts and internal documents, the important thing is to be consistent about the use of capitals and full stops. The usual rules are:
• For list items that are full sentences, begin with a capital letter and end with a full stop.
• For list items that do not contain any full sentences, but contain words or phrases, begin with a lower case letter and do not use a full stop, except for the last item in the list. It is as if the list was a sentence with a full stop at the end.
• For list items that contain a mixture of sentences (or just one sentence) along with words or phrases, begin each part (whether a sentence or not) with a capital letter and end with a full stop.
For example:
There may be various reasons why doctoral theses are not submitted on time.
• The research is not complete.
• Problems may occur with data analysis.
• Writing may go more slowly than expected.
• The student may have started work on another project.
Or:
Doctoral theses may not be submitted on time because of:
• incomplete research
• problems with data analysis
• slowness in writing
• conflicting work commitments.
Or:
Some of the consequences of submitting a poorly prepared manuscript are as follows.
• Rejection. Your paper may not even be sent for peer review.
• Poor impression. The editor or reviewers may consider you to be a sloppy scientist.
• Delayed comments. It may take reviewers longer to provide the editor with their comments.
• More work later. You will eventually have to address the simple things you failed to do in the first place.