Mastering textual mechanics

​​​​​​​Mechanical errors can also reflect badly on you as a credible writer and engineer. Writing mechanics reflect the writer's thoroughness and accuracy. Mechanical errors are especially detrimental when they lead to ambiguous words and sentences, thus resulting in impeding the understanding of the readers. In this section, you will find a list of some common mechanical errors in technical writing. Use this list when proofreading your own technical documents. ​​​

Common mechanical errors:

This means:

Examples

Comma splices

Two sentences are joined with a comma instead of conjunctions (and, but, or, etc.)

Incorrect:

The amplifier was used to increase the intensity of the sound signals, noise in the room became unbearable.

Correct:

The amplifier was used to increase the intensity of the sound signals; noise in the room became unbearable.

The amplifier was used to increase the intensity of the sound signals, but noise in the room became unbearable.

Fused sentences

Two sentences are joined without punctuation

Incorrect:

Please come to my office I need to talk to you.
 

Correct:

Please come to my office. I need to talk to you.

Punctuating citations

Punctuations are placed after, not before, in-text citations

Incorrect:

Indoor air pollution is strongly correlated to cardiovascular diseases. (Smith, 2009)


Correct:

Indoor air pollution is strongly correlated to cardiovascular diseases (Smith, 2009).

Misplaced modifier

Keep modifiers close to the words that they modify

Incorrect:

The device consists of a screw that is inside a barrel that is driven by an electric motor drive.

Correct:

The device consists of a barrel with an enclosed screw that is driven by an electric motor drive.

Parallel structure

Use similar forms of words/ terms for similar ideas (e.g. in a list)

Incorrect:

The sensor responds to various stimuli, including sound, heat, and vibrating objects that may cause disturbances.
 

Correct:

The sensor responds to various stimuli, including sound, heat, and vibrations.

Subject-verb agreement

Verbs must agree with their subjects

Incorrect:

The radiometer, along with the receiver, were placed on the lab bench.


Correct:

The radiometer, along with the receiver, was placed on the lab bench. 

Pronoun agreement

Pronouns must agree with their antecedent nouns

Incorrect:

Everyone on the research team had to receive their training certificates.


Correct:

Everyone on the research team had to receive his or her training certificates.

All members had to receive their training certificates.

Commonly misused words

Some words are mistakenly used interchangeably

Comprise/Compose

Comprise: to embrace or include
Compose: made up of, constituted of
 

Affect/Effect:

Affect: verb (except in psychology)
Effect: noun (except when used to mean “bring about")


Continual/continuous:

Continual: repeatedly
Continuous: without interruption


Its/ it's:

Its: possessive (“of it")
It's: contraction (“it is")


Like/as:

Like: preposition
As: conjunction
 

Principle/principal:

Principal: most important (adj.), most important person (n)
Principle: law

Unnecessary hyphenation

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Use hyphens when two or more words modify another word, and work together as a unit.

Acetic-acid water system
Liquid-gas interface
A 20-percent increase
A two- or three-week incubation period

Do not hyphenate most prefixes added to common nouns.

precooled not pre-cooled
nonpolar not non-polar

When to spell out numbers

Spell out numbers less than 10 and at the beginning of sentences.

Forty-seven percent of the sample evaporated.

The experiment evaporated 47% of the sample.

The experiment included eight samples.

Using units of measurement

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Spell out the unit of measurement when no quantity is included

Several milligrams, not several mg

Do not use plurals for abbreviated units of measurement

60 mg, not 60 mgs

In ranges and series, retain only the first unit of measurement

10-12 mg, between 24 and 50 ml

When a sentence starts with a specific quantity, spell it out along with its unit of measurement

Twenty-five milligrams of acetone were added.

Thirty-seven percent of the sample was dissolved

Use the percent symbol with a numeral form, without a space

30%    65-70%

When to capitalize​

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Numbered items (figures, tables, etc.) should be capitalized when referred to in the text. Write the numbers in numeral form.

As shown in Figure 1
See Table 2
As given in Equation (3)

Non-numbered items are not capitalized.

As shown in the figures

When referring to formulas, equations, and other items with someone's name, capitalize only the name of the author (not the noun).

Avogadro's number

Newton's first law​

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