One of the biggest, if not the biggest, problem of online courses is cheating on tests. And yes, students cheat. I'm talking here about Physics, but I assume i

One of the biggest, if not the biggest, problem of online courses is cheating on tests. And yes, students cheat. I'm talking here about Physics, but I assume it's similar in other disciplines of the hard sciences. This is less so a problem for higher classes -- you can write take-home problems which are hard and uncommon enough that you can't google-solve them. But even then, students will solve them in a team. Or in other words: The best students will solve it, and everybody will have the solution. For lower classes, almost by definition, the problems are all textbook. Yes, you can change numbers around, and formulations, but with some google-fu, most problems are shallow :) The situation gets even harder if you want to be fair to the students who are not on campus. How good is their internet? How do you handle "my internet went down"? Or: I'm in this other timezone, your test is in the middle of the night! What I did in the last semester is allow the students to take the test at any time of the day, and give ample time for the test itself. But of course, that gives them more chance to communicate, and help each other. Even randomized tests (i.e. with changing numbers) do not help here, because often the complication is finding the right formula. Putting in other numbers is then trivial. There are only proctored exams, but they only help if you use a locked down browser. I'd rather not put what amounts to spyware onto my students computers. AND they are pretty easy to fool anyway. The only way around that are taking tests in testing centers. But there is an issue of scale here, especially in COVID times. The second problem is lab classes. It's very hard to teach experimental setup techniques online. How do you use a scope? Can you find a bad connection? Why did this resistor just blow up? You let the students play with sometimes quite expensive equipment, you can not expect them to just have that at home. Third, online teaching is a very bad experience for many students. Not so much of the class itself -- I think this can often be remedied. But things like the exchange with other students, the opportunity to ask the professor face to face, but also so basic things like having to get up and out of your room for class instead of watching it (or a recording) from your bed. Not all, but many students struggled hard to motivate themselves to study sitting at home. I do believe that it's better to have no in-person classes, or maybe a bare minimum. Teachers will try to teach the students as best as possible, but make no mistake, the education of many students will suffer.