A professor may not be in a particularly good position to give a meaningful evaluation for jobs, unless you have done work with the professor outside of a course, such as volunteering or work-study projects.
An employer will primarily be verifying that you have completed the degree you have claimed (which they can do by contacting the university). The hiring manager may have additional questions about specific skills, such as analytical skills or computer tools, or general qualities such as leadership abilities in course related teamwork.
When naming a professor as a reference for a job, therefore, ensure that you are choosing someone who has seen you applying skills relevant to the job.
However much she liked you, a professor in a basic course especially first or second year courses, is not a good choice. Likewise, it is unlikely that a professor would have formed enough of an impression of your abilities through a course marked exclusively on factual recall and small papers comprising easily obtained information.
A good choice would be a professor who instructed a job-related skills course or a course involving independent study or major project, such as your thesis, where he saw you demonstrate skills relevant to the job you are seeking. Even better would be a professor for whom you demonstrated those skills on your own initiative, not just in a lab where she wrote out the procedure and you merely followed the steps. A professor who supervised you in a work-study project is also often appropriate, because she can comment on your capacity to produce output without supervision, take initiative, and other such qualities.
When should I avoid asking a certain professor?
- When you have cheated or plagiarized on their course.
- When you did poorly on their course.
- When you put their course on the back-burner in favour of other courses.
Do not ask a professor for a reference if you have ever cheated on a test or plagiarized an assignment for that professor. Even if you were not disciplined, it may have been because the professor did not have enough unambiguous evidence to prove the charge. Even if the professor never gave any indication of noticing, your cheating or plagiarism may have been quite obvious. If you were disciplined, the professor will likely not give you the silent treatment and will likely continue to be professional toward you, to encourage you to use better judgement in the future. However, it will be hard to give you a favourable reference, particularly in the “integrity” category, if you have cheated. You know where you cheated or plagiarized. Do not use that professor as a reference.
If you did poorly on a course, that professor is a poor choice of reference unless you had a good mark in another courses with the same professor, or you actually understood the course very well. In those cases, the professor may understand that your mark does not fully reflect your ability. This type of discretion is most appropriate when you did learn but the course’s evaluation methods were just not the strongest format for you to demonstrate your mastery of the subject, not for excusing non-academic reasons for why you did not learn.
Think back to whose class you blew off to study for another professor’s tests, whose course you dropped when your course load was heavy, and who you asked for extensions while you worked on another professor’s course assignment first. Do not ask for a reference for the professor you placed on the back burner. It reflected badly on your ability to set priorities when you skipped class and asked for the extension, and it reflects badly on your judgement to ask for a reference from the professor whose subject was not your priority.