MVC (Model-View-Controller) is a very useful programming design pattern in Flash development, but as experienced programmers know, its integration varies from implementation to implementation and programmer to programmer especially because the Flash community is such a diverse one of designers who program and developers who design.
MVC is great in small applications but large application require a programmer to be flexible and practice some ingenuity. Modified approaches such as including abstraction layers for application specific logic keep the MVC architecture cleaner and leaner.
Model - Creates a programming abstraction for an applications data.
View - Inputs/Outputs an application's data. The model-view interaction allows data to have centralized management.
Controller - Processes data received from inputs and translates data to allow integration with model.