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Scientific Writing

A guide to writing papers in a scientific manner, and how to present scientific material.

Common Errors

Error Type Description Incorrect Version Corrected Version
Fragmented Sentence 

The sentence is not complete;

missing a noun, verb, or complete thought.   

Until the centrifuge is repaired. 

We don't know what will happen until the centrifuge is repaired. We're missing the complete thought. 
Until the centrifuge is repaired, the project will be suspended. 
Errors in verb tense or form Errors of verb tense or verb form include writing a sentence that does not indicate clearly when something happened (or will happen) —for example, using eat instead of had eaten.

Mouse R eat pellets by testing time. 

This sentence doesn't make sense.

Mouse R had eaten her pellets by testing time.
Changing tenses When you change tenses, the reader can be easily confused. When verbs indicate present tense and past tense, the reader questions when things are happening.  She takes the sample and had it tested for rabies.  She had taken the sample, so she had it tested for rabies. 
Subject-verb agreement

Your subject and verb should agree. If your subject is singular, so should your verb. A plural noun calls for a plural verb. 


  • If a subject has two or more parts joined by or or 
  • nor, the verb should agree with the part nearest to the verb. 
  • Collective nouns [i.e. group, jury] can be treated as singular or plural, depending on whether they refer to individuals or a unit. 
  • Consider each, either, neither or one to be singular use a singular verb. Both, few, many, others and several are considered plural and require plural forms of verbs. Use context to determine the verb forms for all, any, enough, more, most, none, and some.
For relative pronouns who, which or that, use the noun the pronoun references to discern agreement.

The hardest task on my list were to master cryotherapy.

(task is my noun [singular], were is my verb [plural].
The hardest task on my list was to master cryotherapy. task is my noun [singular], was is my verb [singular]
Dangling Modifiers This happens when words that are being described are not placed close together. This makes it sound like the sentence isn't actually about what it is. The modified words should be IN the sentence.

While perusing the project proposal, it is difficult to read. 

The proposal isn't reading itself, we need to talk about WHO is having the difficulty reading. 
While perusing the project proposal, I find it difficult to read. 
Faulty Parallelism If you're stringing a list of things together, the verb should make sense for ALL the words in the list. If not, use a different verb for each list item. Make sure the verb ends in the same tense While technically he could win fame and fortune, the reference here is to get or increase fame and fortune. This isn't parallel to winning.  John hoped the project would win the contract, garner fame, and increase his fortune. 
Unclear pronoun reference The pronoun must clearly refer to the noun. Be careful when using the pronouns it, they, that, these, those, and which

As a brilliant scientist, that allows him access to the CERN Supercollider. 

He gets access because of his brilliance, but we are talking about HIM as a person. Use the personal pronoun whenever possible
Since he is a brilliant scientist, he is allowed access to the CERN Supercollider. 
Pronoun agreement If your subject, or the noun you're referring to is singular, you should use a singular pronoun. If the subject or referring noun is plural, use the plural pronoun. 

When a student requests an extension, they demonstrate poor time management skills. 

Student is the noun, and it is singular. Using they, a plural pronoun, doesn't agree with our subject. 
When a student requests an extension, he or she demonstrates poor time management skills. 
Omitted commas Commas should be used to set off non-essential parts of a sentence, and to indicate relationships between ideas and parts of the sentence

Although a respected teacher Dr. J made some unethical decisions. 

The point of our sentence is that the dr. made unethical decisions. The introductory part is not essential to the point, and therefore should be set off with commas. 
Although a respected teacher, Dr. J made some unethical decisions. 
Too many commas It's possible to go too far with including commas. Use commas only to set off non-essential part of a sentence, indicate relationships between ideas and parts. Extra commas make your writing harder to read.  It is impossible, to write a paper, that will meet the journal's requirements.  It is impossible to write a paper that will meet the journal's requirements
Comma splice This occurs when a comma is used to join two complete clauses - that is to say, one sentence that could (and should) function as two. Use a semi-colon or period to link the sentences, or rewrite the sentence. Mike took the specimen to the lab, Susan returned the subject to its cage.  Mike took the specimen to the lab. Susan returned the subject to its cage. 
Apostrophe or Possessive errors

Apostrophes are typically used to show possession of an item, or contractions. 

Possessives without apostrophes include its, your, their, and whose.

Contractions include itʼs, youʼre, theyʼre, and whoʼs.

Rachel borrowed they're microscope. 

they're [they are]

their indicates possessive
Rachel borrowed their microscope.