Art and Science of Scientific Writing: Some Rules

Samir Dasgupta*

*Professor & Head
Dept. of Community Medicine
North Bengal Medical College,

[This write-up is primarily intended to give some tips to the post-graduate students and junior researchers for their manuscript or thesis preparation]

  1. Twelve rules for reporting numbers in scientific publications
    (With some examples in parenthesis)

    1. Only Arabic numerals should be used, not Roman.
    2. Avoid using numbers at the beginning of a title or sub-title or a sentence.
    3. For number less than 10, write in words. [ in seven cases….] But if in same sentence, there are less than 10 and 10 or more values, write both in numbers. [ out of 26 seropositives 7 were males ………]
    4. Numbers that represent a statistical or mathematical function should be expressed as numbers, not in words. [ Sample size was multiplied by 2 to take care of design effect]
    5. Do not use ‘zero’ before decimal point if the value above 1 is not possible. [P value was less than .05]
    6. Use a ‘zero’ before decimal point if value above 1 possible. [ Serum creatinine 0.97 mg/dl.]
    7. Report percentage to only one decimal place if the sample size is more than 100. [ Out of 300 study subjects, 40(13.3%) were diabetic]
    8. If sample size is less than 100, there is no need to report percentages with decimal place. [ In the sample of 87 infants, 24(27%) were LBW]
    9. Do not use percentage if the sample is less than 20. [ In the sample of 15 children, 4 suffered from………… ]
    10. Do not give space between number and percent sign. [15%]
    11. Give single space between number and unit. [1900 cal., Hb 12 gm%]
    12. For ranges, use ‘to’ or a ‘comma’ but not ‘--’
  2. Some rules for Reference citation:
  3. Web-based Literature search:
  4. In present days we are too much dependent on Web-based literature search. One major hindrance is problem of plenty. Put a few ‘key words’ in google search, in seconds few millions materials will prop up! How to screen what is ‘necessary’ and what to be discarded?
    General Search Engines vs. Electronic Databases
    General Search Engines (like Google) Electronic databases
    (PUBMED, MEDLARS, The Cochrane library etc.)
    • Problem of plenty
    • Authenticity and validity uncertain
    • Anybody can upload anything there!! (Wikipedia)
    • Source authenticity checked beforehand
    • Data validation done in databases
    • Search can be focused by scientifically formed search query
    Problem under study Congestive heart failure
    Study subjects Elderly
    Intervention under study Digoxin
    Outcome measure Hospitalization
    Type of study RCT
    Comparison None or Placebo
    Language; Language
    Time limit of query Published in last three years
    Abstract or full text Full text
      Example Function
    AND Toxaemia of pregnancy AND low birth weight Retrieves articles where both Toxaemia of pregnancy and low birth weight mentioned, obligatorily related
    OR Toxaemia of pregnancy OR low birth weight Retrieves articles on Toxaemia of pregnancy and/or low birth weight, not necessarily both topics in the same article
    NOT Toxaemia of pregnancy OR low birth weight NOT stillbirths Retrieves articles on Toxaemia of pregnancy and/or low birth weight excluding articles about stillbirths (‘NOT’ is always processed first)
    • Using parenthesis ( ) =
    (smoking OR tobacco) AND cancer
    - Retrieves articles containing: smoking and cancer; tobacco and cancer; but NOT smoking or tobacco when cancer is not mentioned
  5. Language matters - Golden Rules
  6. Value of ‘Title’:
‘Title’ should not be too short or too long, but try to incorporate the above as far as practicable.
“A case-control study to assess risk factors of rheumatic cardiac disease among primary school children in Burdwan municipal area”
End note:

Only a few aspects of scientific writing have been discussed here. Attempt has been made to present in a bullet-point manner so that this may be used as a ready-reckoner by the prospective authors. There are many other areas of scientific writing that may need more elaborate discussion


Many of the concepts, information and examples used in this write-up are from following sources:
  1. ICMJE Recommendations for conduct, reporting, editing and publication of scholarly work in medical journals. ICMJE; Updated December 2014. [ Accessed 23 May 2015]
  2. Albert T. The A-Z of medical writing. BMJ books. 2000.
  3. Taylor RB. The Clinician’s Guide to Medical Writing. Springer. 2006
  4. Vancouver citation styles. Vancouver community college library.2009
  5. Winkler AC, Metherell JR. Writing the research paper: A handbook. 8th Ed. Wadsworth. 2012.
  6. Parikh MN, Hazra A, Mukherjee J, Gogtay N. Research methodology simplified: Every clinician a researcher. Jaypee brothers. 2010.