It simply is a matter of concerns. Ideally, your model should represent the state of your application, it doesn't matter if an event needs to travel one or more layers in order for that to happen. Views may very well be a representation of the model. Although the MV* stack is packed with examples (MVC, MVP, MVVM), here is one example ('Passive View'): http://martinfowler.com/eaaDev/PassiveScreen.html