Um... am I missing something here? You seem to have merely reinvented Object Oriented Programming without the really good bits like Polymorphic method dispatch.

Well spotted.. building a data model that's independent of the actual logic is indeed the first step toward grokking OOP.

Taking this idea to a full OO perspective produces the Model-View-Control program architecture:

• the Model is responsible for all data storage and manipulation.
• the View is responsible for all communication across the boudnary of the program's address space.
• the Control accepts messages from the View, and tells the Model how to set or manipulate its stored values.

Ivar Jacobsen disccusses a similar architecture (at length) in Object-Oriented Software Development: A Use Case Driven approach.

More generally, we're talking about separation of concerns. You can apply the same concepts perfectly well within the framework of procedural programming. The OO/procedural/functional styles are all just syntactic sugar for the basic computing machinery -- state machines, pushdown automata and the like -- and establishing a clear separation of concerns between your data and the logic that manipulates it is a best practice of any programmming style.