Hi Marivic: For me, good back up plans are activities that can be intiated on relatively short notice, are generally related to the course topic, are very low tech, and engage the students so they don't feel like we're just filling up time. When technolgy is not a problem, internet sraches or discovering links to pertinent calss informaion can be a good activity when you have an extra 20 minutes before class ends, or when some students are waiting for other students to complete another activity. As you allude to, discussion is always agreat back-up activity, too. Regards, Barry