Check out scaffolding and fading, by Vygotsky and Jerome Bruner http://edutechwiki.unige.ch/en/Scaffolding

More recently, Ton de Jong and others have written about providing instructional support in the context of using simulations, and how it works best with students with lower metacognitive abilities or less prior knowledge, but doesn’t help and can even hurt students with high metacognitive or high prior knowledge. So, for example, you might have your more experienced participants take another role early on, perhaps helping out “novices”, responding to their questions, etc.