Avoiding Ambiguity

An ambiguous sentence is a sentence that a reader can interpret in two or more ways. Ambiguity has at least two common sources -- word order and word meaning.

A. WORD ORDER

The position of words in a sentence is the principal means of showing their relationship. You should group together words that are related in thought and separate words that are not related. The following conventions address the most common word order problems.

l. Avoid misplaced modifiers.

The careless placement of a modifier may result in the same sentence having several meanings.

DON'T SAY: John saw Jane driving down the street.

SAY: John, while driving down the street, saw Jane.

unless you mean

John saw Jane, who was driving down the street.

2. Avoid indefinite pronouns used as references.

If a pronoun could refer to more than one person or object in a sentence, repeat the name of the individual or object.

DON'T SAY: After the administrator appoints an Assistant, he or she shall supervise the...

SAY: After the Administrator appoints an Assistant, the Assistant shall supervise the...

3. Avoid grouping together two or more prepositional phrases.

A common example of a problem of word order occurs when two or more prepositional phrases are grouped together in a sentence.

DON'T SAY: Each subscriber to a newspaper in Washington, DC.

SAY: Each newspaper subscriber who lives in Washington, DC.

unless you mean

Each subscriber to a newspaper published in Washington, DC.

B. WORD MEANING

Problems of word meaning occur when one word or phrase is open to several possible interpretations. The following conventions address the most common problems of word meaning.

1. Use the singular noun rather than the plural noun.

To the extent your meaning allows, use a singular noun instead of a plural noun. You will avoid the problem of whether the rule applies separately to each member of a class or jointly to the class as a whole.

2. Draft an expression of time as accurately as possible.

You can eliminate uncertainty as to when a time period begins or ends by clearly stating the first and last days of that period.

DON'T SAY: From July 1, 19___, until June 30, 19___.

SAY: After June 30, 19___, and before July 1, 19___.

If a time period is measured in whole days, use the word "day" instead of "time". A reader may interpret the word "time" to mean an exact time during the day or night an event occurs.

DON'T SAY: Thirty days after the time when...

SAY: Thirty days after the day on which....

Avoid the use of time relational words such as "now", "presently", and "currently" in your regulations. Use of these words to relate a provision in your regulations to the time the regulations takes effect creates an ambiguity. It is unclear whether the provision in the regulations should change if the "current" fact changes after the regulation takes effect.

DON'T SAY: The Mayor of the District of Columbia is entitled to a salary equal to that of a GS-15, step 2, as now prescribed by law.

[You know what the Mayor's salary is on the day the regulation takes effect but what salary does the Mayor receive if Congress changes the pay rate for a GS-15 one week, one month, or one year after the regulation takes effect?]

If, in the example above, you intend the provision to remain unchanged after the regulation takes effect, it is better to determine what the provision would be on the day the regulation takes effect and write that specific provision into your regulation.

SAY: The Mayor of the District of Columbia is entitled to a salary of $____________.

However, if you intend the provision to change as time passes, make that fact clear.

SAY: The Mayor of the District of Columbia is entitled to a salary equal to that of GS-15, step 2. The GS-15, step 2, salary is adjusted by Congress.

3. Draft an expression of age as accurately as possible.

Similar problems occur when you express an age requirement. The expression "more than 21 years old" has two possible meanings. A person may be "more than 21" on his or her 21st birthday, or on his or her 22nd birthday. Depending upon which meaning you intend, clarify the ambiguity as follows:

DON'T SAY: A person who is more than 21 years old...

SAY: A person who is 21 years old or older...

unless you mean

A person who is 22 years old or older...

DON'T SAY: Between the ages of 16 and 20...

SAY: Sixteen years old or older and under 21...

4. Do not use privisos.

The priviso is archaic, legalistic, and usually results in a long and unintelligible sentence. Use the following drafting conventions to avoid expressions such as "provided however" and "provided always".

• To introduce a qualification or limitation to the rule, use "but".
• To introduce an exception to the rule, use "except that".
• To introduce a condition to the rule, use "if".
• If the clause is a separate complete thought, start a new sentence or subsection.