This semester, I'm a TA (teaching assistant) for CS155: Data Mining. I took the class last year liked it, and TAing a class (any class) was on my Caltech bucket list, so I jumped at the chance to volunteer for the TA position at the end of last year. The professor for the class is my academic advisor, so I floated the idea in a meeting with him and he was happy to have the help!
TAing at Caltech is a paid position, so I'm not exactly a volunteer. The amount of work that the job requires changes depending on the class you are helping to teach, the enrollment in the class, and on the number of other TAs. This year, CS155 has 160 students and six TAs. We have decided to split up the work so that each TA teaches one recitation (an optional, supplementary lecture once a week) and handles two of the nine assignments. "Handling" one of the assignments entails holding office hours (a period of time, about 1-2 hours, during the week before the assignment is due where TAs make themselves available for students to ask questions about the lectures or assignments), and grading the subsequent submissions.
This means that I have 160 problem sets to grade twice this term. Luckily, each problem set is split between 2-3 TAs so I am grading only one 3-part question on each problem set, but if you spend 3-4 minutes grading each submission that'll still take you...nine hours. At least we're getting paid well for it!
But being a TA can also be a bit of pressure. I feel like I have to be a complete expert on the topic of the assignment the week that I'm "on," even beyond the amount I knew about the subject after taking this class the year previously. I know that when I'm taking a class at Caltech, I rely on the TAs in office hours to be able to answer any question I have, and they almost always pull through. Having had so many great TAs in the past, I'm definitely feeling the pressure to bring my A game, now that it's my turn, and this means that I'm spending a lot of time outside of my classes and other work researching the topics I'm supposed to be on top of. That's just part of the job, I guess!