Sample may be adapted.
Dear [Name of Employer]:
This reference letter is provided at the written request of [name of student], who has asked me to serve as a reference on [his/her] behalf. It is my understanding that [name of student] is being considered by your organization for the position of [job title]. Please be advised that the information contained in this letter is confidential and should be treated as such. The information should not be disclosed to [name of student, if student has waived access] or anyone in your organization who would not be involved in the hiring decision regarding this individual. Additionally, the information should not be disclosed to anyone outside of your organization without the consent of the student.
I have known [name of student] for the past [number of months, semesters, years] as [he/she] has taken the following courses which I teach: [list courses, give brief description of content of course]. As [his/her] professor, I have had an opportunity to observe the student's participation and interaction in class and to evaluate the student's knowledge of the subject matter. I would rate the student's overall performance in these subjects as [below average, average, above average]. This is evidenced by [his/her] grades—[state the grades].
[One or two specific examples of the student's performance may be appropriate.] As part of [his/her] grade in [name of course], the student was required to prepare a paper. The paper was designed to measure the student's ability to research, to analyze the results of the research, and to write. [Discuss how the paper submitted by the student indicated to you the student's skills in these areas.] Based upon this, I rate the student's skills [indicate rating].
[It may be appropriate to give specific examples about the student's area of expertise.]
Based upon the student's academic performance and my understanding of the position for which the student is applying, I believe the student would perform [place overall evaluation here].
If you would like to discuss this further, please feel free to contact me.