Summary
A brief look at some of the most commonly confused words in technical and scientific writing.

Common Confusions in Technical/Scientific Writing

Since we're focusing on editing tonight, I decided to jot down a few of the most commonly confused words and phrases in technical and scientific writing.

Can vs. May

Word	Definition	Example
can	is able to	This computer can execute one billion instructions per second.
may	having permission to	If you have write permission on the directory, you may create a file in it.

In technical writing, "can" is common but "may" is relatively rare (unless you are talking about security issues).

Comprises vs. Constitutes

Word	Definition	Example
comprises	synonymous with "includes"	A zoo comprises mammals, reptiles, and birds.
constitutes	the elements that make up the set.	Mammals, reptiles, and birds constitute a zoo.

e.g., i.e., and etc.

Though fine in academic writing and scientific writing, you should avoid Latin abbreviations such as etc., e.g., and i.e. in technical writing as they confuse many readers. However, if you do use them, at least use them correctly.

Word Definition/English Replacement Example

etc. and so on Object-oriented languages such as Java, C++, SmallTalk, etc. support polymorphism.

i.e., that is C is the Latin of computer languages; i.e., C is rarely in practical use today but is at the heart of many of the languages that followed it.

e.g. for example Citrus fruits (e.g., lemons, limes, and oranges) prefer temperatures above 25.

Word	Definition/English Replacement	Example
etc.	and so on	Object-oriented languages such as Java, C++, SmallTalk, etc. support polymorphism.
i.e.,	that is	C is the Latin of computer languages; i.e., C is rarely in practical use today but is at the heart of many of the languages that followed it.
e.g.	for example	Citrus fruits (e.g., lemons, limes, and oranges) prefer temperatures above 25.

Effect vs Affect

These words are confused all the time (with good reason). Each word has multiple meanings. Also, the meanings change somewhat depending on whether the words are being used as a noun or as a verb. Cutting to the chase, we'll concentrate on their most common uses in technical and scientific writing:

As a Verb

Word Definition Example

to affect to influence Air pressure affects acoustics. (Air pressure influences accoustics.)

to effect to bring into existence Desert rain effects desert flowers. (Desert rain gives birth to desert flowers.)

Word	Definition	Example
to affect	to influence	Air pressure affects acoustics. (Air pressure influences accoustics.)
to effect	to bring into existence	Desert rain effects desert flowers. (Desert rain gives birth to desert flowers.)

Note that many writers misuse "effect" when they mean "affect." If confused, just avoid these words and use their synonyms.

As a noun, "effect" means "the result" or "the outcome." For example:

The drug had an immediate effect on the pain.
To produce the desired effect, just add salt.

"The shape of our language is not rigid; in questions of usage we have no lawgiver whose word is final."