I think a successful science classroom that is integrating modeling and simulation would be one that employs the use, modify, create scaffold to ensure that at all times, students are working up to the proper cognitive level. I would not expect all students to flow through this scaffold at the same time, and so the teacher would need to be a facilitator as students move through the process. Of course, the teacher would need to provide basic solid core content instruction and students would need to feel confident with how to use the technology available to them. I see the teacher introducing a simulation or computer model in a whole class setting, and then allow time for students to explore on a individual basis, and assessing which students are achieving learning targets based on simply using the model. I see students working in pairs to discuss how they could modify the computer model and experimenting with those modifications. With regards to creating their own model, I don't think all students would always get to that cognitive level, so I see the teacher working with small groups to facilitate the creation of a new computer model by the students themselves. The student created model could then be introduced to the class for individual use, to help solidify the content knowledge of all students, especially struggling students, and provide opportunities for students to discuss the thought behind model creation among their peers.