My approach requires students to have done the reading before coming to class because I put them in groups or put them on the spot to answer questions about the texts we are analyzing that day.
If students haven't read the material, I suspect they get pretty bored pretty fast and then want to have read the texts for the next times. I find that there are always enough students who have read the material to carry the dialogue.
Things to consider with this approach requiring prereading:
1. Keep readings short on days when assignments are due. Students are usually scrambling to get the assignment done (and sometimes barely that). I sometimes will then read the texts (or pertinent parts) aloud, so that I know that all who are there have then heard it at least once, and for those who have read the material, the rereading reinforces and enhances their own.
2. If the students are in small groups, I circulate to make sure that at least a couple of students in each group have read the material so they can have a dialogue (in the truest sense of the word).
3. I have sent students who haven't preread the material off to read it while the rest of us start in on discussion. When they come back, they join the discussion (I've only done that a couple of times, but they came back).
Judy Johnson