For more information contact: Özgür Selsil .
Several lecturers have used e-clickers in their lectures in the past. These enable you to ask questions which students answer by pressing buttons on their e-clickers: the answers are automatically analysed and a distribution can be displayed. Socrative is a free system which allows you to do similar things, and more, in a very simple way using students' smartphones - it avoids the need to carry bags of clickers to lectures. As the lecturer, you can run the activity from your own smartphone if you have one, or alternatively from your laptop or the computer in a teaching room. The system has been used successfully by Özgür Selsil in large classes.
There is a nice video on the Socrative website showing you how to get started. Briefly, you create an account in advance and login to it from t.socrative.com. You are given a virtual room number, and you ask students to go to m.socrative.com and meet you in this virtual room. Once this is established, you start an activity such as a multiple choice survey or test. Students' responses are visible on your device instantly. It is very simple...
Clearly this is not suitable for formal assessment, as we cannot require students to have smartphones. Moreover, Socrative claims there is a limit of 50 students for each activity, though it looks as if this is only precautionary. If you have a large class, then dividing it into two groups and asking questions of the groups alternately may be more reliable than overloading the virtual room. Students who don't have smartphones can be asked to discuss their answers with neighbours who have.