Two hundred years ago Samuel Johnson (who wrote one the first dictionaries of the English language) offered this devastatingly clever appraisal to a would-be author: "Your manuscript is both good and original; but the part that is good is not original, and the part that is original is not good."

Even Groucho Marx got into the act when he stung S. J. Perelman with this unforgettable zinger: "From the moment I picked your book up until I laid it down I was convulsed with laughter. Someday I intend reading it."

Few people can match the wit of a Samuel Johnson or a Groucho Marx. But if your goal is to help people write successfully on the job rather than put them down or make points at their expense, you don’t have to be witty. All you have to do is follow these six principles of constructive criticism.

1. Purpose. Remember your purpose: to help the people who write for you produce the best document they are capable of producing, not to establish your superiority as the better writer or to demand that the author write exactly as you do. Good critics tend to think of themselves as coaches rather than judges.

2. Tone. Good critics take care to use a positive tone. They don’t just mark the errors or problems they see (for example, "awkward" or "poorly worded"). Instead, they offer suggestions for correcting them (for example, "Try this wording: . . ." or "Offer more explanation here."). Consider your own experience: Do you find it easier to write for a sympathetic or a hostile reader? For which reader are you more likely to do your best writing?

3. Emphasis. Good critics tend to be more descriptive than evaluative or judgmental. They approach errors as problems to be solved rather than as points to be tallied in their assessment of the writer’s worth. An example of descriptive comment is: "Your meaning here isn’t clear to me. Explain or illustrate your point." An example of evaluative comment is: "This is irrelevant and confusing."

4. Scope. Good critics address the author’s purpose as well as make text-editing suggestions. They try to go beyond the surface problems of a text (punctuation, grammar, and word choice) to deeper issues of purpose, approach, logic, and organization. Recognizing that editing text is easier than producing it (just as reviewing books is easier than writing them), good critics try to help the author not only with the easier but with the more difficult parts of the writing process.

5. Balance. Writers need both specific suggestions and general comment. Good critics try to strike a balance: They offer specific recommendations for altering the text as well as more general explanations of what aspects of the writing worked and didn’t work for them.

6. Clarity in expectations. When making assignments, good critics are clear and explicit about their expectations. It’s more efficient – and easier on the author’s ego – if you communicate what you want before rather than after the author has written and submitted an assignment. Two good ways to communicate your expectations are to offer examples of the kind of writing you want and to provide not only oral but written guidelines. In other words, if you want clear writing, give clear instructions.

Recently I was asked to facilitate a discussion in a workplace where tensions were running high, and I thought I had the answers. As it turned out, I think I was the one who learned the most.

I began by reminding the writers and editors present that both parties sometimes hold misconceptions about editing relationships.

Editors, I pointed out, tend to assume that there’s only one right way to say something, that editing is harder than writing, and that the main function of managers is to edit. Questionable assumptions all.

Writers, for their part, sometimes wrongly assume that most editing is pointless tinkering, that editors must know more about the content than the writers to offer valid criticism, and that competent writers don’t need editors.

Mix those assumptions in with some strong personalities and a high-pressure work environment, and you’re likely to have trouble. But the more we talked, the more I began to suspect that something else was going on here.

After the participants listened politely to my introduction, they asked the following questions: Why do we edit? How good is good enough? And who owns the work?

I was just about to venture an answer to the first question when one writer said, "We edit in hopes that a creative conversation takes place so that the final version is better than either the original version or the editor’s version."

Was I impressed! Here was a succinct statement of rationale for nearly all collaboration. Collective wisdom is hard to beat – that is, unless the process of communicating and acting on that wisdom becomes cumbersome.

In response to the second question – How good is good enough? – one editor said, "The problem is that when I receive negative criticism on something I’ve edited and passed on, that criticism is conveyed only to me rather than also to the department head who drafted the text. As a result, I feel like I’m caught in the middle."

I knew from talking with other staff members that some of them thought this particular editor was too critical in her editing, and I had assumed the main problem was simple: an overly zealous editor. Now I was realizing the situation was more complicated.

Next we talked about who owns the work, and we concluded all involved parties did – the writer, the editor, and the organization – and we reminded ourselves that it was especially important for the writers to retain a sense of ownership.

I was most impressed when I asked for their conclusions. Here’s what they told me: (1) Agree on a set of ground rules – for both the editing process and the mechanics of language; (2) communicate expectations early on – before, rather than after, something has been written and edited; and (3) close the feedback loop.