Students often can provide valuable responses to questions that are put to them directly, responses which they might not otherwise volunteer. A faculty member of business administration keeps the class roll in front of him and calls upon students at random to answer questions based on the reading. It's terrifying for some students, at least at first, but it's very effective. If students can't respond because they have not done the assigned reading, they will feel badly. But they will usually make a greater effort to be prepared to participate in subsequent class meetings.
Many law professors use a similar strategy, but one employs a slight variation.
At the beginning of the term she asks those students who do not wish to be called on to write their names on a piece of paper. She then places a star next to their names as a reminder to pass them by. I find that few students exercise this option and some that do change their minds over the course of the term.