Not long ago, a very articulate historian who often blogs about teaching and research headed a post "I feel dirty." "I just wrote a letter," she explained, "that I really shouldn't have written." Asked to write in support of a bright student who often failed to show up and engaged in other self-defeating practices, she realized that "there was not very much concrete about the student that I could recommend. This person has buckets of potential, that much is true, and that much is about what I said. But it was a hard letter, and a short letter, and, I'm afraid, not an especially helpful letter." New Kid on the Hallway resolved that in future she would tell students like this that she could not write effectively for them—a decision warmly supported by most of the correspondents who responded to her blog.

The dilemma this young historian faced—whether to write a vague and not very favorable letter or refuse to write one at all—is only one of the hard problems that historians face when asked to write recommendations. We begin doing this, for the most part, while we are still graduate students ourselves, writing law school and scholarship recommendations for undergraduates. As lecturers and assistant professors, we find our services in wider demand, and begin to write file letters that will help to shape the careers of graduate students. Tenured professors, finally, write for advisees searching for research fellowships, postdocs, and tenure-track jobs, and colleagues hoping to win tenure or a year at a research center, as well as for their students. Every senior scholar's word processor contains a massive file of recommendations, one that grows from year to year. Central though letter-writing is throughout careers, there are no formal rules for the craft. We learn by writing—and by reading what our colleagues write.

In order to stimulate discussion and to help young historians begin to write effective letters, the Professional Division has asked three distinguished scholars who have worked in a variety of settings to offer their counsels. Robert Darnton, Paula Findlen, and Guido Ruggiero make clear that a good letter has to be something of a work of art. Precise, lucid, unpretentious, a good letter must somehow make clear what is distinctive about the person being recommended—and do so in a way appropriate to the particular fellowship or job that he or she is applying for. Their essays sketch the outlines of an etiquette of letter-writing and suggest criteria that students and junior faculty can use when choosing referees, and referees can use as they draw up their recommendations. They also warn against many practices, some traditional and some new, that deprive many letters of utility for potential employers or research sponsors. All the essays have been discussed and approved by Council at its meeting on January 4, 2007, and are thus also offered as AHA guides to good practices.

One point needs special emphasis. Those who ask for letters of recommendation, as well as those who provide them, should think carefully about what they are doing. It's always most effective to ask the scholars and teachers who know you best—rather than those who may seem more famous—to write on your behalf. It's always important to make this request well in advance of deadlines, and, if you are on the same continent as the letter-writer, to provide clear addresses (or, even better, stamped and addressed envelopes). As your career develops, moreover, you should continue to ask yourself if your referees are the ones who serve you best. If you never contact someone except to ask for a recommendation, you should think again. Someone who plays no active role in your intellectual life is not the logical person to assess your accomplishments and convey to others what you do particularly well. It is always the responsibility of the one asking for recommendations to provide up-to-date curricula vitae, copies of recent work, and other information that can enable a letter-writer to refresh his or her work.

Naturally, no formula will suit all cases. But these concrete and thoughtful recommendations will help those who are new to this part of our professional practice work out a constructive and effective personal style, and give the experienced ideas to work with as they continue to refine their practices. Letters belong to the routine part of our lives—and in the fall, that part that comes to seem a heavy burden. But nothing we do every day does more to shape the lives and careers of our students and our colleagues.

—Anthony Grafton (Princeton Univ.) is vice president of the AHA's Professional Division.