When Should You Use a Hyphen?

Wise counsel from Richard Lauchman, author of Punctuation at Work: Simple Principles for Achieving Clarity and Good Style:

Say you come across the following sentence:

“The study should yield more conclusive results.”

Does this sentence mean that additional conclusive results are required, or that results that are more conclusive are required?

In the latter instance, meaning requires more-conclusive results.

As in cases of this sort, it’s better to use a hyphen than to omit one just because the rules say it shouldn't be there. Here are three guidelines to consider when hyphenating:

1. Break the Rule When Doing So Helps Your Reader
Nearly all authorities say you shouldn’t hyphenate compound adjectives when the first word is comparative or superlatives: “most favored nation” or “less developed countries.”

Break this rule when your meaning requires it. In the sentence below, taken from the New York Times, notice how lower-ranking is handled:

“The only other figure from the Bush White House to have been convicted of a serious crime is Donald McGonegal, a lower-ranking official who has been sentenced to 18 months in connection with the Jack Abramoff lobbying scandal.”

Even though readers would probably get this meaning, the hyphen enables them to get it a little more quickly.

2. Know Your Audience
Phrases like spread spectrum analysis and frequency hopping system require no hyphen at FCC because they have become terms of art among communications engineers. If, however, you’re writing to a nonexpert audience, then you’re encouraged to hyphenate spread-spectrum and frequency-hopping.

3. Value Clarity Above All Else
It’s better to use a hyphen when the rules say you shouldn’t than to omit one when the reader needs it. Your readers don’t care about the rules of hyphenation. They care about clarity. I encourage you to hyphenate whenever doing so helps prevent ambiguity or facilitates understanding.

The compound adjectives below all begin with superlatives (which by rule aren’t supposed to require a hyphen), but the reader benefits when you hyphenate because he sees your intention a little more quickly. That is what we want.

•   the best-case scenario
•   the best-kept secret
•   the least-recognized fact
•   the worst-conceived plan
•   the least-annoying error
•   the weirdest-rule award