How to write a letter of recommendation

by Michael Ernst ([e-mail])
October, 2002

(Also see my advice on requestingrecommendation letters, and Shriram Krishnamurthi's advice to graduateschool recommendation letter writers.)

At the beginning of the letter, say how well you know the person, for howlong, and how you became acquainted. Also give an overview or summary ofyour recommendation.

Be specific. Don't just praise the person with generalities (such as“quick learner”), but give specific stories or anecdotes about things theperson did to give you that impression.A letter that praises a person without being concrete comes across as atepid recommendation.Rankings in class are another example of ahelpful specific.

Differentiate. Say how this person is unlike other people: his or herspecific strengths.

Compare. When writing to someone who shares context with you, name names.(“In the top 5% of the class” is OK, but much better is“Equivalent in promise to my former students Donny Knuth and Al Turing,but a notch below Johnny von Neumann.”)

Be plausible. Don't make the person out to be perfect. Often a letterjust ignores shortcomings, but then the letter lacks credibility; writingsuch letters will hurt people you recommend in the future. If the personhas shortcomings, admit them or note some ways the person can improve,particularly if the person has started to overcome those problems. Don'tmake up faults nor magnify real ones.

State your own qualifications. How many other people have you seen who areof the caliber expected by the reader? (For a recommedation to a top-10 school such as UW, the recommendation will carry more weight if the recommender has spent time at a top-10 school. Only someone with first-handexperience can give a truly accurate assessment.)These qualifications are probably best-suited to apostscript, though sometimes they are written as the first paragraph toestablish credibility.

Justify your recommendations.Don't write a statement like "The applicant is definitely qualified foryour institution/award/program" (especially with "your institution"verbatim as in aform letter, not substituted by an actual name). This weakens rather thanstrengthens the letter, because the reader will assume that the form letterwas sent to many places, and the statement cannot be true of every recipient.

Don't be too brief. One paragraph, or two short paragraphs, is the kiss ofdeath. (If you don't know the student well, and don't have much to say,add a short paragraph explaining what the course is and why it's good that thestudent excelled in it. This won't fool most people, but will soften theblow of a short letter.)However, don't ramble: make it succinct and to the point. Whoever readsyour letter is probably reading hundreds of other letters. If the keypoints of yours do not pop out, or the reader wearies midway through yourletter, then your letter will net be effective.

For situations where the letter has a disproportionate impact (e.g., forfaculty applications), or if you are new to recommendation-writing,treat your letter like any other important piece ofwriting: get feedback from others.

If you are requested to provide a letter in PDF, provide the original PDFthat was created by your word processor or typesetting program. Don't scanthe document, which degrades the visual quality and makes it much harder to read. No one really careswhether your original signature is on the letter, so you can insert a scanned signature into the PDF or even use a typewrittensignature. You don't wanteyestrain (or anything else) to lessen the impact of your letter.For similar reasons, don't use "watermark" letterhead that puts a large,dim image (for example, of your university crest or logo) behind yourtext. You may think this looks cool and sets your letter or institution apart,but in fact it makes your letter harder to read without impressing anyone.

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Mayfield Handbook: Writing Letters of Recommendation

(The MayfieldHandbook is compilation of suggestions and style tips useful for alltypes of writing.The following is from its “Writing Letters ofRecommendation” section.)

Write letters of recommendation to provide relevant information and topresent an individual truthfully and positively.

Guidelines for Writing Letters of Recommendation

Before writing the letter:

• In most cases, agree to write a letter of recommendation only if you can honestly write a supportive letter. If you cannot portray an individual positively, decline to write the recommendation.
• Ask for a current resume and as complete a description as possible of the position or program to which the person is applying.
• Assemble and review all other relevant information you may have about the person you are recommending. It is often easy to overlook some important accomplishment.

Writing the letter:

• Present the person truthfully but positively. A recommendation that paints an unrealistic picture of a candidate may be discounted. A recommendation that focuses on negative qualities may do more harm than intended.
• Tailor the recommendation to the position. A letter recommending an individual for a job as a camp counselor should contain different information from that in a letter recommending the same individual for a job as a computer programmer.
• Begin the letter by describing how you know the individual you are recommending and the specific contexts upon which you are basing your evaluation. In what situations have you known the individual? For how long? How closely?
• Present the individual's general qualities relevant to the position along with one or two detailed examples. Including vivid detail will make the recommendation much more effective.
• In most cases, a letter of recommendation should consist of three or four paragraphs and not be over one page in length.

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A bad recommendation letter

Here is a real example of a letter of recommendation that I received for aPhD applicant. An eminent faculty member first sent a content-free recommendation letter, so I asked for more information. This was the response. You can see that this letter, though positive on its face,violates nearly every rule about writing a recommendation letter.It saddens me that lack of thoughtfulness on the part of the advisor meantthat we had to reject the student's application (though it's possible thatthe advisor truly thought the student was unworthy and was signaling thisobliquely via the letter).

Dear Prof. Ernst:It is my pleasure to write this letter and recommend [omitted], one of myfavorite students, for the admission to the Co-PhD Study Program at yourlaboratory.[omitted] is an enthusiastic and progressive young man with extremely highpotentialities. He is not only quick at learning and good at solvingcomplicated problems, but also with a logical and creative mind thatenables him to raise some insightful views. I was also deeply impressedwith his diligence and outstanding communication ability, compared with myother students. What's more, he is an optimistic man with pleasantpersonality, and gets along well with all the people around him. I hope hecould further broaden his vision and accumulate research and programmingexperience to get him more fruitful.I believe in your laboratory, which possesses a wonderful researchfoundation for program analysis and software security, his excellentcompetence, coupled with your preeminent guidance, will assure him ofacademic achievements in his future academic pursuits.Thanks for your letter, if you have any other questions, please contact mefreely.[Signature]