Lashunkeita,
Since this approach is working for the majority of your students I think you might want to continue it if you are pleased with the results. For those that don't get into I would talk with them and try to determine why. They can give you insight as to why they are don't want to be a part of this activity. Something I do to get input and questions from every student is to give each student a 3X5 card and have them write down 2 questions want to get answers to. I have found this to work very well because then I can call on the students that don't want to participate knowing they have two questions written down and they can read to the class. After we are done with our session I have them put their names on the cards and hand them in. I quickly look through the cards to see if I am missing and key points in the question time. By putting their names on the cards there is a level of accountability on the part of the students, though I do not score them or anything. I just throw the cards away.
Gary
Gary Meers, Ed.D.