(Concerning cell phones) Is it rude....

[the]

Of course it is. I believe you know this.

Of course I know what is socially acceptable, although I think it shouldnt be a big deal.

 

[Quest]

Yes, it is.

If it's an important message, of course you can attend to it, but it would be considerate to let the person you're speaking to know -instead of just chatting or texting away.

 

[arbygil]

It's rude.

Even in a large lecture hall - your instructor sees you, they really do. I occasionally teach in the summers to large groups, and it bugs me when I see students not paying attention.

This is usually what works: Whatever you're lecturing on, tell the class very calmly (without changing the tone of your voice) that what you're about to say could be on the test (and put it on the test!). Those who were paying attention will get the question. Those who weren't, won't. But I'd use it as a bonus question anyway. It's not fair for those who had emergencies or whatnots.

But it does bug me when I see people not paying attention to what I'm saying.