The Teaching Assistant’s Role in the Classroom
Frequently students take courses taught at least partially by teaching assistants. The exact duties of teaching assistants (TAs) vary by institution, department, and instructor. Some TAs grade essays. Others conduct labs and discussion sections of classes. Still others work alongside faculty in course planning, preparing and delivering lectures, and creating and grading exams. Depending on the professor the TA may act much like an instructor with supervised control of the course. At many universities students have lots of contact with TA's but not as much with faculty members. Because of this, many applicants feel that a TA knows them best and is able to write on their behalf. Is it a good idea to request a recommendation letter from a teaching assistant?
Who to Ask for a Recommendation
Your letter should come from professors who know you well and can attest to your abilities. Seek letters from professors who taught courses in which you excelled and those with whom you have worked. Most students have no difficulty identifying one or two faculty members who are well qualified to write on their behalf but the third letter is often very challenging. It may seem like the instructors you have the most experience with and who perhaps best understand your work are TAs. Should you ask for recommendation letter from a TA? Generally, no.
Teaching Assistants are Not Preferred Letter Writers
Consider the purpose of the recommendation letter. Professors offer a perspective that graduate student teaching assistants cannot. They have taught a greater number of students for a greater number of years and with that experience they are better able to judge applicants’ abilities and promise. Moreover graduate programs want professors’ expertise. Graduate student teaching assistants do not have the perspective or the experience to judge potential or provide a recommendation as they are still students. They have not finished their PhD's, are not professors nor do they have professional experience to be able to judge an undergraduate potential for success in graduate school. In addition, some faculty and admissions committees hold a negative view of recommendation letters from TAs. A recommendation letter from a teaching assistant might damage your application and reduce your odds of acceptance.
Consider a Collaborative Letter
While a letter from a TA is not helpful, a TA might provide information and details to inform a professor’s letter. The TA may know you better than professor in charge of the course, but is the professor's word that has more merit. Speak with the TA and the professor to request a letter signed by both.
In many cases the TA might provide the meat of your letter – the details, the examples, the explanation of personal qualities. The professor may then weigh in as the professor is in a better position to evaluate you and to compare you with current and prior students. If you seek a collaborative letter be sure to give information to both the TA and professor to ensure that both have the information they need to write a helpful letter of recommendation