One of the classes at my undergad. was taught entirely by a TA without any professor supervision. Since the TA had all the responsibilities that a professor has and our class was never introduced to a professor, I had assumed the TA was actually the professor and had her write me a letter. Recently, I found out about this and contacted the TA regarding this letter. She told me that T.A. are considered instructors in the case of this particular class. She also informed me that even though there is no professor, this class does have a course coordinator. This is one of my strongest letters so would hate to not be able to use it. Has any of you guys have experience with getting a Letter of Recommendation written by a TA and cosigned by the professor/course co-ordinator? any advice will be appreciated!