<p>I was a TA myself and while I enjoyed the experience, I agree with @jack63 - I feel like it extended my time to degree. And I actually really like teaching and liked my students, but it takes up so much time! How much work you do depends on the professor themselves. Some professors are very structured and will only need you to grade exams and meet with students, and they do all the lecturing and creating assignments. At some schools, students infrequently attend office hours, so those positions are more about showing up to sit in lecture and office hours and the grading. Other classes you are leading your own lab or recitation session, and you might have to create exams and assignments and grade them. You also have to meet with students. I think quantitative disciplines overall might be more demanding on TAs’ time, because the students seek out more help. Teaching statistics (which I love) is always more time-consuming than teaching other classes for me.</p>
<p>At the same time, I wouldn’t say to completely avoid teaching assistantships, but mostly because of debt. Debt isn’t freedom. If we’re talking about a parent paying the entire bill out of pocket vs. the student TAing, then I guess that could be a big more freeing. But if we’re talking about borrowing all that money vs. taking a TAship, my perspective is that you are trading long-term flexiblity for short-term freedom. If you pay your own way with loans during the program, sure, you can decide better what to do with your time DURING the program. But afterwards, your job options may be more limited because you have financial considerations. This may be less of a concern for engineers who make pretty high salaries to begin with, so of course consider this in terms of your son’s own program and abilities/desires. But someone with $100K in loans from their master’s program can’t decide to take an awesome $40K/year job (that maybe is a stepping stone to a really awesome $70K/year job down the road), not to mention that kind of debt is a specter that hangs over auto financing, home loans, and perhaps his children’s own college educations years down the road.</p>
<p>In my field, at least, blacklisting is very uncommon. You might be unable to get a good recommendation from a professor, but ethics prevents the majority of professors from calling around and telling their colleagues not to take a student - although if the professor is called by a colleague, he may certainly relay negative information about that student. However, I think simply deciding to leave a lab isn’t enough to spur most sane professors to blacklist you. (It has happened, though, so it’s not impossible. I’ve heard stories. I just think that the chances are slim.)</p>
<p>The other thing is that if you want a PhD, future PIs will expect that you have done research in your MS program, if you have an MS. You’ll have to work in someone’s lab, regardless of whether you decide to stay there or not.</p>