Raising your hand only tells the professor that you, an individual, are confused. Interruptions by a single student that doesn't understand the material, when the rest of the class does, might actually cause the professor to focus too much attention on a subject that doesn't need it.

This is far better. There will always be a couple people that are not following. If the professor is getting 90% "I understood" responses, he can simply mention that anyone with questions on that topic is free to meet them after class, while the rest of the time can be spent on topics where there is a lower rate of understanding.

Thanks for the feedback! In large classes students tend to be reluctant to raise their hands (especially in classes with 200+ students). ESL students are also unlikely to raise their hand and say they don't get it. I actually tested the app in 3 first year classes and it didn't seem to be distracting.

I'm hoping to add a feature for leaving feedback at the end of a lecture, great idea!

Also great idea on the Occupy Wall Street idea!

I go to a small college where average class size is around 20 students. People hardly ever raise their hand.

Overwhelming majority of students are deathly afraid of looking like an idiot by raising their hand. It happens everywhere, not just large classrooms.

I think this is a great idea.

I went to a small college too... In a class of 10-20, it was pretty easy for the professors to know when we were confused since she was looking at each of us.

Exactly right. I teach at a uni in South Korea. Students who never lived/traveled outside the country will never, ever raise their hands if they don't understand. Not only that, but if you ask them outright, they will nod and say clearly, "yes, I understand", and then turn to their best friends and say in Korean, "I actually don't understand any of it".

This app would be a tremendous help not just to my classes (I've been here a long while, and know how to read the signs of confusion & check understanding), but also to the classes of newbies in Korea.

New teachers here sometimes go for months naively asking students "do you understand this stuff" and believing it to be true.

If Koreans could vote on this anonymously, I think they would actually do that at every opportunity.

I like cutting the input down to only "confused". You can just assume the remaining people logged into that "room" are not confused - either they understand it or are comfortably making sense of it.

Wish I had that for my calc lectures...

This can also be a problem in my opinion. Imagine you are only able to enter "confused". Then as soon you are using this app in a class room everyone who sees that you are using the app knows that you will enter "confused". This is a problem for many people I guess. You don't wanna lose your face sometimes. Hm - one solution to this could be to make the UI of the app absolutely generic or exchangeable. I would also build in a random delay between the "tap" on the button and the actual transmission of the data to the "lecturer". The delay can be minimal but this makes it hard to track it back to the source.