The Writing Center @ The University of Wisconsin - Madison
The Writer's Handbook
An Editing Checklist

8. Superfluous commas

Unnecessary commas make sentences difficult to read.

Unclear:

Field trips are required, in several courses, such as, botany and geology.

Clear:

Field trips are required in several courses, such as botany and geology.

Unclear:

The term, "scientific illiteracy," has become almost a cliche, in educational circles.

Clear:

The term "scientific illiteracy" has become almost a cliche in educational circles.

For more information on commas see Commas: Punctuating Restrictive and Non-restrictive Modifiers and Punctuating Coordinating Conjunctions and Sentence Adverbs, or take one of the free grammar, style, and style classes offered by the Writing Center.