I use mobile device based voting via Google forms in my classes, and this has generally worked well. But there can be problems! I have just posted the following message in the forum for my first-year module.
I’d like to make a plea for people to take the polls/votes in classes seriously. Well, I think many of you do already, but there appears to be significant distortion introduced by those who don’t.
These polls and the associated discussions between students have an important role in your learning, and provide an opportunity for a form of interaction in the large class we have.
You are already getting most of the benefits if you are attempting the problems and trying to persuade your neighbours that your answers are right. Explaining your reasoning to another student is a very good way to solidify your own understanding of the material! From this point of view, distortion in the vote/poll doesn’t matter so much. However, I would like to be able to gauge how well the class is following at a particular point, and whether I need to explain the question again or give extra hints.
It is hard for me to judge what the situation is if the results are distorted. So please do take the votes seriously, so that I can take appropriate action based on the results.