Give the students a questionnaire after the video. Tell them beforehand that
you will do this. The questionnaire should be completed in about 10 min.
Choose the questions so that they cover topics for which the students need a
better understanding. The students can answer as individuals if a small class
or as groups in a large class. Discuss the correct answers with them and get the students to contribute to the discussion. Some competition and incentive for the students can be introduced - the questionnaire can contribute marks or you
could even have some sort of prize. You might need a play-off in the event of
a draw - have some extra questions ready. Hope this works for you.