Group contingency Assignment

What type of group contingency would you use? Describe how you might work on that and why you chose that. How would you set up the programming for this individual?

SCENARIO: You are in a 5th grade elementary classroom. One of the things that you notice is that there are alot of shoutouts during the class presentation/group presentation that the teacher is doing. Shoutouts mean that the student is not raising his/her hand and they just shout out answers right now. What the teacher would like to do is reduce the number of shoutouts so that this is not disruptive to the class and she can reward raising hand and have students want to be called on. When taking baseline what the teacher found is that the students as a whole shouted out somewhere between 15-20 times per class period for an entire week. This was always during ELA class and right now teacher is just taking data. Teacher want to look at different types of group contingencies. Which one would you use? Why did you select that one? What is going to be the contingency that's in place? What could possible rewards be? How are you as teacher going to change that behavior to start to reduce the amount of shoutouts over time? ELA teacher would like to get it down to 3 to 4 per class period.