User:Antaeus Feldspar/Intro sections

A recurring question that comes up for almost every article is: what should go in the intro section, and what should go in the main body instead? Here are some ideas to consider on the question:

Interface vs. Implementation
Computer scientists, in talking about computer components (hardware or software) talk about the interface and the implementation. The interface is what the component does: what it takes for inputs, and what it emits for outputs and errors. The implementation is how the component does what it does: how it calculates its outputs from the inputs it receives.

How does this relate to Wikipedia articles? Consider the intro section as the place to discuss the interface -- what the subject is to their field, to history, or to the world -- and the main body as the place to discuss the implementation -- the history of the subject, the personal life if a person, the whos and hows.