Anything that comes between the writer and the reader's mind is a barrier to communication and should be eliminated. There are three broad categories of these barriers:

Incorrect grammar

English grammar is logical. In fact, if we make grammatical mistakes we can easily change the meaning of what we say. There is a difference, for example, between these two sentences:

"The copywriters, who handled the client newsletters, were an asset to the firm." "The copywriters who handled the client newsletters were an asset to the firm."

The insertion of a pair of commas in the first sentence tells us that all the copywriters handled the client newsletters and so all were an asset to the firm. In the second, only some handled the client newsletters, and they were the ones who were an asset to the firm.

Which of the following two sentences is correct?

"Mary likes John more than me." "Mary likes John more than I."

Whichever one you chose, you are right! Both sentences are grammatically correct, but they have different meanings. The first means Mary likes John more than she likes me, whereas the second tells me Mary likes John more than I like John.

Grammar is important to meaning, and we ignore it at our peril.

Long, rambling sentences

A law firm engaged in writing a new brochure asked the partners for their ideas. The memo from one partner contained this sentence:

A threshold issue, in my view, is whether our marketing information should be used to simply describe what we are and, therefore, preserve the status quo or rather, to describe where we want to be and what we want to be within the reality of who we are and thereby, hopefully, create new opportunities.

Wha-at? A sentence with 54 words is rarely clear, as this one illustrates. Sometimes you can clarify meaning simply by breaking it into two or more short sentences. But some sentences, like this one, are a lost cause! I have no idea what the writer meant, and I'm sure the intended reader didn't either. (This is why non-marketing professionals shouldn't write brochures!)

Inappropriate use of jargon

Imagine a cocktail party conversation among a doctor, a lawyer, a banker, a plumber and a rock musician, all using their own professional jargon. Total chaos! Using jargon to write to people outside our professions, or even our organizations, has precisely the same effect.

Never assume people will understand your jargon, your special language. Next time you are tempted to use "insider" words, ask yourself if they will really mean anything to this particular audience. Jargon-filled messages won't even be read, let alone understood and acted on.