Scientific writing

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Introduction

See also Citation management | Scientific journal | Research for librarians - portal

Style of writing and use of English in essays and scientific papers

Good scientific writing is the basis of all scientific communication. Well-written articles are critical in presenting science in a logical manner and in accordance with accepted styles. The scientific format used to acknowledge bibliographic resources is also important. A good writing style is aided by logical planning. Decide what you want to write and proceed to do so in a sensible order. Put the first draft aside for a while and then revise. Have a respected colleague review and edit your paper.

Suggestions for better scientific writing:

• Divide text into sentences and paragraphs. Sentences should have one idea or concept. In general, scientific prose should be short but full stops should not be added such that the writing does not flow. Using paragraphs helps the reader to appreciate the ideas you are expressing.
• Superfluous phrases and words should be removed. Do not write phrases such as "It is also important to bear in mind the following considerations". Woolly phrases and weasel words can be omitted or replaced by a better single word.
• Use familiar, precise words rather than far-fetched vagaries. Try "cheaper" to replace "more economically viable."

Use the past tense unless you are describing present or future circumstances. Use the active voice. Active voice is easier to read and reduces sentence length which is important as most scientific journals have a word limit. Indiscriminate changes in tense are confusing and lead to unintended meanings. Write in more than one tense in the literature review e.g. "Brown (1995) showed that the brain is more fully developed at birth than other organs". In this case the present tense can be used for the second half of the sentence because its gives knowledge that can applied generally. Materials and methods should be written in the past tense. Any conclusions should also be in the past tense, e.g. Health librarians found that ....etc. Keep in mind that the purpose of scientific writing is to convey information. This cannot be done if you write in long sentences. Keep sentences short, not more than 30 words in length. A sentence should contain one or two related ideas.

• HINARI Authorship Skills

Principles of paraphrasing

• Principles of Paraphrasing: How to Avoid Inadvertent Plagiarism

• online tutorial developed by the Harvard Graduate School of Education (HGSE) explains paraphrasing and avoiding inadvertent plagiarism of other ideas and writers

Choice of words

Words have precise meaning and using them correctly adds clarity and precision to what you want to communicate in writing. Look at the following pairs of words that are often used in scientific texts. Learn how to use them correctly: Fewer, less; infer, imply; as, because; disinterested, uninterested ; alibi, excuse ; data, datum; later, latter; causal, casual; loose, lose; mute, moot; discrete, discreet. Use a standard dictionary and Roget's Thesaurus of English Words and Phrases to find the correct meaning of words.

• Examples to show difference between less and fewer by using the two words:

Less active blood cells Fewer active blood cells

When you write ‘it’, ‘this’, ‘which’ or ‘they’ are you sure of their meaning? A pronoun usually refers to the nearest previous noun of the same number (singular or plural) The cows ate the food; they were white. The cows ate the food; it was white.

Correct spelling, including the use of plurals

Some words have alternate spellings e.g. tyre, tire, grey, gray; draft, draught; connexion, connection, plow, plough, often the difference is between the American, Canadian and British spellings. Other spelling problems are based on misuse of a word e.g., principle and principal; practice, practise (The former a noun, the latter a verb). The plural of many words in English is achieved by adding an s (or es). Some words have the same form in both the singular and plural. For example some singulars are also plurals (sheep - there is no such word as sheeps). Some words are already pluralized such as information and people, so don't use peoples (unless you are referring to different groups of people or different ethnic groups). Adopted words take on the plural of the original language, for example datum becomes data; and fungus become fungi.

Use concrete statements to achieve clarity and precision. "Cessation of plant growth operated in some of the plots." Obviously a cessation cannot operate (Some plots of plants did not grow during the trial) The abstract noun basis is commonly overworked. "Measurement of storm intensity involves recording staff to be available both day and night on a 24 hour basis." "To measure storm intensity recording staff have to be on duty throughout the day and night."

Use of the present

Having said that the cow stood up. After standing in boiling water for an hour, examine the flask.

A gerund ends in 'ing.' If the sentence is left without a subject (a hanging participle) then the action of the verb is transferred to the object of the sentence (first sentence) or to the person taking the action (second sentence).

Misuse of words (avoid)

• One cannot develop a logical argument using emotional words: e.g. progressive, reckless, crank, sound, good, correct, terrorist, freedom fighter, insurgent, sexist, imperialist, improved, superior, deviationist, fascist.
• Very, more, much, have a place if used economically but are out of place in academic writing. Superlatives such as gigantic, earth shattering or fantastic should be deleted.
• Qualifying the absolute: some adjectives are absolute and cannot be modified: sterile or unique. Other adjectives, such as "pregnant" should be qualified carefully. A petri dish is either sterile or not; it cannot be very sterile, quite sterile or fairly sterile. An object is unique, and although a woman can be recently pregnant she can not be slightly pregnant.

Loose expressions (avoid)

• Bulls with a high milk yield tend to have fat percentages below average. Do bulls produce milk?
• Ewes were fed on a pregnant maintenance ration. Clearly the ration was not pregnant.
• In each selected village 30 farmers were interviewed, namely 10 large, average and small farmers. Is the reference here to the size of the farmers or to the size of their farms?

Jargon (quotations by J Oliver (1968))

• avoid scientific jargon; scientific writing should inform using simple language not confuse using grandiose words or phrases.
• Grand phrasing: The ideal fungicide ... must combine high fungitoxicity with low mammalian toxicity and phytotoxicity, and with an absence of tainting or other deleterious side effects when the fruit is processed.
• Simple alternate: The ideal fungicide ... must kill fungus effectively, but must be harmless to animals and plants, and cause no tainting or harmful side effects when processed.
• Grandiloquent phrase: The phenomenon can be macroscopically observed upon laparotomy.
• Simple replacement: Visible to the naked eye on opening bird's cavity.
• Avoid overuse of "the"; use the when applied to an item referred to before, e.g. 'the various patients' may have been mentioned before. All others can be omitted.
• Avoid excessive use of indefinite pronouns "it".
• "It would thus appear that" can be replaced by "apparently";
• "It is evident that" by "evidently";
• Other commonly used phrases such as: "It will be seen that"; "It is interesting to note that" and "It is thought that", can be edited out.
• Some phrases show sloppy thinking. For example, the phrase 'It has long been known that' usually means that the writer has not bothered to look up the reference. Correct to an order of magnitude probably means that the answer was wrong. Almost reached significance at the 5% level usually means a selective interpretation of results.
• Text is easier to understand if simple words and phrases can be used to replace more complex or foreign ones. For example ameliorate can be replaced by improve; analogous by similar; anthropogenic by human; component by part; ingenuous by innocent; ingenious by clever; interalia by among other things; utilise by use; Prima facie by at first glance; remunerate by pay; terminate by end; pari passu by at the same rate, pace or time and peruse by read.

Punctuation

• a colon, is used when a list or explanation follows, a semi colon is used to separate two or more related clauses provided each clause forms a full sentence
• apostrophes are used to indicate absence of a letter e.g. isn’t it (for is not it) doesn’t (for does not). Note the difference between (it is) it’s a boy and its, which is the possessive of it (everything in its place)or To denote possession (the boy’s bike). If a word ends in s, the apostrophe may be placed after it and the final s omitted (the calves’ eyes).
• most uses of commas in scientific writing are given; a comma is put in a sentence to denote a brief pause between groups of words:

I will show you the paper about which I was speaking, but it is not as useful as I first thought.

Or to separate subclauses:

Professor Brown, who is in charge of recruiting for the University, said that the latest estimates were higher than those for this time last year.

Finally to separate all items in a list except for the last two;

The following items may be imported duty free into Azania: Animals, cereals, plants, fruit, trees, legumes and nuts.

Observe the importance of the comma paced between fruit and trees in this particular list.

Other points concerning the use of English

One common mistake for those whose language is not English is to not match verb with noun. A singular verb must be associated with a singular noun, and a plural verb with plural noun; some exceptions exist where a singular noun is used in a plural sense (for example, ‘number’ in this sentence) or a plural noun is used in a singular sense (for example, ‘headquarters’). Here, the verb can agree with the sense of the noun's usage. Difficulties arise with nouns which do not end in ‘s’ in the plural form. For example, livestock and data are best used as plural.

Numbers and Units

Quantities should be given as figures can be justified. The metabolic rate should not be quoted as 326.18W if it can be measured to within about 5%. It should be written as 330W. Figures within a number should be grouped (with a small space between each) so that they are easier to read. Commas should be avoided. For example: 21 306.1 not 21,306.1 The Systeme International (SI) should be used where possible. Some common units and their abbreviations are given below. The full stop is not used in the SI system. When incorporating statistical data into the text, the test used (eg chi squared) should be included, along with the degrees of freedom, the calculated value and the P value.

The layout of a scientific paper

The layout for a scientific paper usually follows a structured abstract format with:

• A title,
• An abstract,
• An introduction (which is made up of a brief literature review),
• Materials and methods,
• Experimental,
• Results,
• Conclusions,
• Acknowledgements and a
• List of references .

How to start a scientific paper

Specialized scientific reviews and books provide a good introduction to this subject. They will provide additional references, some of which may be published in journals that are available in local libraries. A good knowledge of existing information is essential in scientific research. Sir Isaac Newton memorably said:

• I can see further because I stand on the shoulders of giants.

Scientists save time with observation and experiment by accepting data in the literature. However, statements in published articles are not necessarily true however:

• Subjects have seldom been studied exhaustively
• Recent advances in techniques or design of experiments lead to additional observations
• These may lead to a different interpretations
• Therefore new enquiry may be needed.

Scientists should review the literature and determine whether modifications are necessary.

Sources of information that may be consulted in the preparation of a literature review on a scientific subject

Many sources of information can be used to find information and used to write a scientific paper. Some sources are not as reliable as others. Information from popular sources is less reliable than from scientific papers. The list below indicates the usefulness of sources (from 1 the most popular to 11 most scientific, up to date and reliable):

1. non-academic website
2. scientific textbooks
3. articles on science subjects in journals
4. on-line journals (not refereed)
5. popular journals, e.g. New Scientist http://www.newscientist.com
6. review articles (e.g. Nutrition Abstracts and Reviews or in 'Trends' journals such as Trends in Plant Science).
7. grey literature (i.e. information not readily available); conference proceedings, research reports, annual reports.
8. science citation index
9. theses
10. scientific papers (refereed on-line journals)

Titles for essays and scientific papers

The title should indicate what the essay contains and be as concise as possible. Sacrifice brevity for clarity. The title should be a concise summary of the paper. Include important nouns or key words and then join together within the title. Examples 'The limitations of maize(corn) as an energy source in diets for children' 'The feeding of rice straw and sorghum tops with molasses and urea to cattle' Key words: Maize, corn, humans, diets, rice straw, sorghum, molasses, urea, and cattle When an essay or a paper is being written, an author should constantly refer back to the title to ensure that what is being written is encompassed by the title. J. Oliver, in his book on scientific writing (written in the 1960s), quotes an example where he was looking for paper on 'Acknowledgements'. He could not find it in the indexes because the paper was entitled Independence in Publication. In other words the keyword 'acknowledgements' was missing from the title. This type of problem is less likely to arise today because most searches today are made electronically on databases. These searches include searches of keywords words included in the abstract as well as those in the title. It is highly probable that the word acknowledgments would have occurred in the abstract and he would have found the paper for which he was looking. Unconscious humour or inaccuracies should also be avoided in titles, e.g.one quoted by J.Oliver : Freezing and storage of human semen in 50 healthy medical students. (It is to be hoped that the medical students remained healthy and fertile after such an experiment). Various types of title can be used for a paper:

Types of title that can be used for scientific papers

• informative titles give an indication of results achieved, conclusions drawn and the paper's subject matter

• e.g. Bed nets control mosquitoes most effectively when used in the rainy season.

• questioning titles ask something provocative for readers: When are bed nets most effective when used to control mosquitoes?
• main-subtitle (series) type; indicates a series of papers on one subject; an approach editors of scientific journals may not like as they may feel duty bound to accept sequels. e.g. The effect of bed nets on mosquitoes: 1) Their effectiveness when used only in the rainy season.

How to write titles

Ensure that the title:

• Describes the contents of the paper; is accurate, concise and specific
• Has as many key words as possible and is modelled on the style adopted by the publication for which you are writing
• Is as easy to understand as possible

The title should not:

• Contain a full stop, unless it is an informative title
• Contain unnecessary words such as "Some notes on....……. "An investigation into..……..
• Contain abbreviations, formulas and acronyms
• Promise more than is in the paper
• Be too general

In most cases when writing a title of a scientific paper the title should be followed by the author's name and full address of the institution where the work was carried out. If an author has moved, his/her new address should be added as a footnote.

How to write abstracts

The abstract should expand on the title. Remember the abstract will be read by more people than the paper. An informative abstract contains a summary of main points in the essay or paper. To prepare an informative abstract an author should read the essay or paper, making notes as he or she progresses. An abstract for a book is written as an indicative one amd tells you what subject matter the book covers; it is not a summary of all its contents. Abstracts should not contain: references to tables or figures, because these appear in the paper; abbreviations or acronyms unless they are standard or explained; references to literature cited; any conclusions not in the paper.

Introductions

An introduction to a scientific paper should normally not exceed 400 words (check the requirements of the Journal to which you intend to submit your paper) and it should cover the following subjects:

• Background to the subject to be investigated
• Give an brief overview of the state of knowledge quoting appropriate references
• Identify gaps in existing knowledge
• Explains the reason for the current investigation

Materials and methods

This section should deal with four main topics:

• Equipment and materials used
• Experimental design
• Observations made
• Methods of analysis used, statistical (and chemical if required)

Results

This section typically contains concrete data and analysis:

• information that the investigation has generated
• tables and graphs that summarize data
• main features presented in the tables and graphs

NB. The data in tables and graphs should be clearly understood without reference to text; texts should be clearly written without reference to tables and graphs

Discussion and conclusions

• Should compare results with results of other research
• Should draw reasoned conclusions
• Should compare these conclusions with those drawn by other workers
• Should indicate the practical implications of the findings
• Should indicate what further research is needed

Acknowledgements

These should be clear and any help of academic, scientific or technical nature should be acknowledged. But if the acknowledgement is overdone there is a danger that the reader will wonder what contribution the author made to the paper. For example: 'I wish to thank Dr. Lester, who not only suggested most of the experimental design but also greatly helped with the interpretation of the results, Dr Brown who contributed greatly to the writing of the paper and Mr A.S.Brown who carried out most of the experimental work'.

Tables and graphs in scientific papers

Tables should be numbered in a continuous sequence through the essay. Each table must be referred to in the text, but it may also have a heading clearly showing its content. The units of any numbers in the table must be clearly stated. If the table was synthesized from data published in previous publications these references must be cited. The inclusion of a large number of tables makes the text difficult to read and should be avoided. Sometimes data can be more clearly presented as graphs rather than tables. If it is necessary to include tables which are relevant but not essential for an understanding of the text they should be put in an appendix. Tables should be clearly understandable without reference to the text and vice versa. The text should be used to explain the main parts of a table. Graphs and other figures should also be numbered sequentially. Each must have a self-explanatory heading, and must be referred to in the text. The axes of graphs should be clearly labelled and must give the units.

Citation of reference in the text

Reference may be cited in two ways. Either "Brown, Smith and Jones (2006) and Abdulahi (1998) confirmed these results..." or "These results were confirmed by similar experiments (Brown, Smith and Jones,2005; Abdulahi , 2006)". The names of all authors (but not their initials) should be given the first time the reference is cited in the text. For subsequent iterations, where there are four or more authors, an abbreviation of the form "Brown et al. (2001)..." can be used. Where more than one reference is used for the same author in one year, lower case letters should be used to distinguish between them, for example, "McLean (2002b)".

List of references and end of paper

The reference section contains a list of all the references cited in the text. References should be arranged in alphabetical order (according to the name of the first author). Each reference to an article should contain the following:

1. Name (or names) of author(s), (each) followed by initials
2. Year of publication in parenthesis
3. Title of article
4. Title of journal, either in full or abbreviated according to the World List of Scientific Periodicals
5. Volume of journal, underlined
6. Number of first and last pages of articles

For example:

Hutber AM, Kitching RP. The role of management segregations in the control of intra-herd foot and mouth disease. Tropical Animal Health and Production. 2000;32:285-294.

Each reference to a book should contain:

a) Name(s) and year, as above.

b) Title of book. The most important words in the title should be given in capital letters e.g. Milk and Beef Production in the Tropics (N.B. this applies to the titles of books only).

c) Publisher and place of publication e.g. Oxford University Press, London

Each reference to an article which is published in a book or Conference Proceedings should also contain the title of the book and its editor. For example:

Chalmers EE. Advantages and disadvantages of nomadism with particular reference to the Republic of Sudan. In: Beef Cattle Production in Developing Countries. Centre for Tropical Veterinary Medicine, Edinburgh.

Attention should be paid to uniformity of punctuation. Please check the list of references, since it is very frustrating for the reader to find that references in the text are not included, or that they are wrongly quoted. Make sure that references in the text are in the reference list - Programs such as Word, Papyrus, and Endnote can assist with this chore and that of putting references in order.