Expressions to be Avoided in Writing a Scientific Paper or Thesis

Lindsay [1] gives ten categories of cumbersome expressions that should be avoided in writing a scientific paper or thesis. These are summarized below (using his examples, mostly):

  1. Clusters of nouns. When clustered together, all nouns except the last function as adjectives. Avoid expressions like “chemical healing suppression” and say instead,“suppression of healing by chemicals”, or “suppression of chemical healing”, or whatever else you intended to mean. Use prepositions to make your meaning clear.
  2. Adjectival clauses. Instead of “an innovation based return on investment culture”, say“a culture of innovation based on return-on-investment” or whatever you actually meant to say. Again, use prepositions to make your meaning clear, even if this construction is longer.
  3. Subordinate clauses at the beginning. This style puts the unimportant bits first and the important ones later. It may be good electronics to do so (Least Significant Bit first), but it is bad English. Avoid beginning sentences with constructions like “Despite the fact that . . . ”, “Notwithstanding the fact that . . . ”, etc. Compare these two versions:Thus, although there were too few plots  to show all of the interactions which we sought [subordinate clause, apologetic], under the conditions of the experiment [subordinate phrase, conditional], copper and zinc acted additively [1, p 47].Thus, copper and zinc acted additively under the conditions of our experiment, although there were . . . [1, p 47]The second sentence certainly reads better. It is also a good example of putting the important information in the topic position, which is at the beginning
  4. Nouns instead of the verbs from which they are derived. Avoid writing “Recording of pulse rates was made”; instead write, “Pulse rates were recorded”. We have improved the original sentence in three ways by doing this. We have:*replaced the original dummy verb “made” with the genuine verb “recorded”;
    *shortened the sentence; and
    *sharpened the impact.
  5. Use of filler verbs. Do not write “We conducted a study of group III-V compounds”; instead say, “We studied group III-V compounds”. The second sentence has five words; the first, eight. Again, a dummy verb has been replaced with a genuine verb and the sentence has been shortened and strengthened. Examples of dummy verb constructions to be avoided are “to be present”, “to occur”, “to perform”, “to obtain”,etc.
  6. Use of passive voice rather than active voice. Passive voice is appropriate when the doer of an action is unknown or is irrelevant. Otherwise, passive voice lengthens and weakens the sentence, whereas active voice is direct, succinct and more forceful. Compare “Patients were observed by two people for signs of abnormal behavior ” [1,p 49] with “Two people observed the patients . . . ” [1, p 49].
  7. Use of imprecise words. Do not use words like “quite”, “some”, “considerable”, “a great deal”, etc. in scientific writing. It is imprecise and unhelpful to the reader.Be quantitative: you are writing an engineering thesis. Sometimes, you may wish to avoid numerical precision for some compelling reason. If you want to avoid writing “Fifty-two percent of the images were correctly classified”, do not say “The majority of the images were correctly classified”, but rather “Slightly over half the images were correctly classified”.
  8. Use of compound prepositions. Debaters and politicians use expressions like “in the case of”, “in respect of”, etc., usually to gain time to think of a proper answer during a debate or a press conference. Such expressions dilute the force of the simple, direct statement: they have no place in your thesis.
  9. Multiple negatives. A double negative, when used carefully, has impact or conveys just the right shade of meaning. Multiple negatives do not. They serve only to confuse and should be avoided. What does “not unreasonably inefficient” really mean? Anytime you cause your reader to backtrack or pause for mental breath to take in meaning, you have done yourself and your reader a disservice.
  10. Unfamiliar abbreviations and symbols. Stick to SI units and prefixes. If you have to introduce a new unit called a flip make sure that you define it somewhere, introduce an abbreviation consistent with the SI system, use SI prefixes, and stick with your nomenclature all through.


  1. D. Lindsay, A Guide to Scientific Writing. Melbourne, Australia: Addison Wesley Longman Australia, 2nd ed., 1997.
  2.  Chandrasekhar, R. (2002). How to write a thesis: A working guide. (pp. 20). The University of Western Australia.

1 Comment
  1. Daniel Mukuni says

    Really helpful! Points number 5 and 6 have clearly explained to me why I was never able to compress my work!

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