Made as simple as possible, but not simpler.
Values like “3” are typically considered separately from constraints like “< 10” or types like “number”.
Do you repeatedly define the same field/attribute across different classes / entity types?
Consider “basic theories” that are particularly simple in two ways.
In order to integrate quantitative data, you need to know (a) if units are commensurate, and (b) if so, how to do conversions.