One object, several accounts
An individual part, the connections between parts, and the behaviour of a whole system can each be a useful focus. Moving between those views is not simply a matter of adding more detail. It may require a different description.
A model is useful when its choices match the question. The most detailed model is not automatically the most informative one for every purpose.
Choose what to keep
Simplification makes a complex subject easier to examine. It also creates responsibilities: explain what was omitted, why it seemed reasonable, and where the simplified account may stop being useful.
When a conclusion is carried from one scale to another, look for the assumptions that travel with it. A relationship observed in one setting is a reason to investigate the next setting, not a substitute for that investigation.
Keep the frame visible
- Which scale best matches the question?
- What relationships disappear when the view is simplified?
- What evidence would justify carrying the explanation into a new setting?
A visible frame makes it easier to compare explanations and to know when a different view is needed.