Guidelines for asking for letters of recommendation

Letters of Recommendation:

I write dozens of letters of recommendation every year. This literally takes days of my time in december. Please make my job easier, and help me to write you a better letter, by following the guidelines below.

If you would like me to write you a letter of recommendation, please give me a packet with as much of the following information as possible:

Your resume
Your statement of purpose, or some similar document
A summary of key or memorable interactions that we have had. e.g.:

"I was the student in office hours who had the idea about making an XOR gate ..."
"You looked at my final project and said that I was the only one who ..."
"I usually sat on the right side of class and asked lots of questions."

In addition, please be sure to:

provide envelopes with the appropriate address and postage if necessary. Most applications are online now, but in some cases they still want letters. I will send the letters directly to their institutional destinations. Letters will be given directly to students only under rare circumstances.
to the extent possible, give me all of the materials in one packet, rather than bringing things to my office item by item.

Once you have given me the information packet, please do not hound me to see if I have written the letter. One email around the time that the letters are "due" is appropriate, to make sure that I haven't lost the packet or forgotten about you.

If I tell you that I don't know you well enough to write you a letter, believe me! If you insist, then I will write a letter that states "I do not know this person well enough to write him a letter of recommendation." Your application is much stronger with two good letters than it would be with two good letters and a very weak letter.