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“...we recommend reading as many as possible articles regarding your fields of interest to examine how other authors have structured the presented information”
Scientific writing has a distinctive style: the writer needs to be clear, succinct, precise and logical. In scientific writing it is also essential to consider your audience.
Research findings should be stated in clear simple English in a scientific report. Meandering, descriptive, decorative text is inappropriate. It should be impossible to misinterpret your findings.
Jargon is words or phrases that only specialist readers will understand. Using such jargon without explanation can make your work unintelligible to the majority of readers. Even if you are sure your supervisor or tutor will understand it, you should write as though they are intelligent non-specialists and make sure everything is explained sufficiently.
Some jargon is unavoidable and not every scientific word needs an explanation. However, always think if there is a standard English word or phrase that can be used instead. Also consider that some scientific tests etc may be superseded and so don't just assume that a future reader will know what they are testing for. Make sure you include such information.
Acronyms and abbreviations
These are a type of jargon that can actually be useful in certain circumstances; for example, where they are used to avoid repeatedly writing complicated phrases in full. In such cases always give them in full the first time you use them and if you need to use a lot of them, consider having a list of them at the beginning of your report.
Functional activation of growth factors and receptors of the epidermal growth factor receptor (EGFR) family occurs in most epithelial-cell cancers, rendering EGFR a target for cancer treatment. (From Ciardiello et al., 2008).
Scientific writing needs to be brief - in depth concepts should not be made more complicated and confusing.
Redundant phrases should be avoided. For example:
|Example redundant phrase*||Improved|
|Smooth to the touch||Smooth|
|Costs a total of||Costs|
*from the 'Concise Writing Guide, Garbl's Writing Centre
Avoid using unhelpful or unnecessary verbs in your writing, especially when describing what you did. For example, instead of:
Analysis of the DNA was performed using electrophoresis.
it is better to simply write.
The DNA was analysed using electrophoresis.
Choose your words carefully when you are writing science. In theory, someone who reads your scientific report should be able to repeat your experiments. Also, your reader should know exactly how your results relate to each other and to the results of others.
The use of vague adjectives in scientific writing is inappropriate - you need to convey your exact meaning. For example, is your large increase a ten-fold increase or a ten thousand-fold increase? Say exactly what you mean, avoiding any ambiguity.
Every argument in your scientific report should be logical. An argument is a final claim that is made based on at least one other claim. The final claim is known as the ‘conclusion’, and the claims that are used to support the conclusion are known as ‘premises’.
In a sound argument:
- the premises should be true
- the conclusion should be assured, or very likely, based on the premises
Knowing your audience
Remember who will read your work, and why they are reading it. Will your reader understand your explanations? Your tutor/supervisor will often understand the work already but you should write as though they may not. Do your explanations demonstrate that YOU understand everything?
Learning from others
Draw inspiration from journal articles which you or your supervisor/tutor feel are well presented. Read through the articles that you have chosen, and ask yourself the following questions:
- What have the authors included in the abstract/summary?
- How much space is dedicated to each of the different sections?
- How frequently are references used? What are the references used for?
- Which techniques does the author use to keep different sections of the article brief?
- How do the authors introduce their articles? Do they start broadly and then focus on their topic? Is any knowledge assumed?
- How are the methods described? How much detail is provided?
- How is the data presented? Is the data described in the text? How frequently are figures referred to in the text? How have figures and tables been labelled? Which kinds of figures and tables are the easiest to read? Which kinds of figures show the results most effectively?
- How do the authors reach conclusions? Do they refer to the work of other authors to provide support for their conclusions? Are any problems with the experiments discussed? What techniques do authors use to explain results that don’t fit?
Tenses are tricky. Even well respected journals differ in the guidance they give their authors for their use. The overall move is for increasing use of the present tense but this can cause difficulties, especially when describing your rationale and methods - where a lot of what you refer to or did clearly took place in the past. As with all scientific writing, the most important things are ensuring clarity and avoiding ambiguity.
Here we offer some basic guidance but this is by no means definitive. A more in depth consideration, looking at each section of a scientific paper can be found here: Verb tenses in scientific manuscripts.
When to use the past tense
- To describe your methods (things you did) and the results you obtained:
Pitfall traps were placed every 25m on the sample line.
The core species showed a non-random pattern of site colonisation.
- Describing the findings/observations of other researchers that were applicable at that time or in those circumstances:
In an early study, Sharkey et al. (1991) found that isoprene emissions were doubled in leaves on sunnier sides of oak and aspen trees.
Multigene expression-based assays were found to help treatment decisions for patients with breast cancer (Schmidt et al., 2016).
Had these been written in the present tense, it would imply that these were more universal, general findings which could be misleading.
When to use the present tense
- When you are making assertions about established knowledge (or knowledge you believe to be established):
Gel electrophoresis of DNA is one of the most frequently used techniques in molecular biology.
Hybridization with free-ranging domestic cats threatens the survival of indigenous European wildcat (Felis silvestris silvestris) populations.
- It can be acceptable to use the present tense in abstracts, when you are introducing the main findings of your study (see cautionary note below).
These results indicate that...
This study shows that...
Cautionary note: Ensure that you include as many caveats as are necessary to avoid unsubstantiated generalisations. i.e. These results indicate that in x circumstances at y time ...
Using the past tense can be more appropriate i.e. The results indicated that ... as this makes it more focused on your study.
When to use the future tense
- When you indicating possible projections and consequences:
Should this trend continue, it suggests that the population will rise by 12% over the next five years.
As with tenses, the use of the active or passive voice in scientific writing is the topic of much debate. Many scientific journals now ask writers to abandon the long established norm of using the passive voice and use the active voice instead. There are however, times when the passive voice is still the preferred option.
What is the difference?
In a sentence that uses the active voice the subject of the sentence acts/acted:
The panda ate the bamboo leaves. (subject = panda)
In a sentence that uses the passive voice, the subject of the sentence is acted upon:
The bamboo leaves were eaten by the panda. (subject = bamboo leaves)
What is good about the active voice?
- It is shorter (always a good thing in scientific writing - see Be succinct above)
- It is more direct/vigorous (more persuasive, less stilted)
Active: Tobacco companies rejected the claim that smoking caused lung cancers.
Passive: The claim that smoking caused lung cancers was rejected by tobacco companies.
- It prevents ambiguity about who did the action (subjects are often missed out completely when using the passive voice)
What is good about the passive voice?
- It emphasises what was done. This is often more important than by whom. In a methods section, it can be assumed that the researcher was the actor and using the passive voice means this can be removed from the sentence completely which shortens it and prevents repetition:
Active: The researcher placed pitfall traps every 25m on the sample line.
Passive: Pitfall traps were placed every 25m on the sample line.
- It prevents overuse of personal pronouns. Generally the use of I and we is discouraged in scientific writing at undergraduate level. There is nothing wrong with them per se but they can create too much repetition (I did this, I did that). Once you are writing for Nature (who encourage them), you can bring them back in!
- It maintains flow by keeping the subject consistent. For example, if you are writing about the pancreas then the following sentence would be best:
The pancreas produces and secretes large amounts of digestive enzymes. (active)
However, if your focus was on digestive enzymes, then this can create better flow:
Digestive enzymes are produced and secreted by the pancreas. (passive)
So which is best?
The short answer is both. The best writing using a mix of active and passive voices. The most important thing is to make the decision purposefully rather than just habitually choosing the passive option.