Everything discussed so far was based on mathematical constructs turned into modeling notations. The majority of specification languages were invented elsewhere and used as thinking and communication aides. Almost universally these are diagrammatic notations, and any formal semantics comes later.
cannot overemphasize how much the pre-existing paper tools of domain experts are the visualization designer's friend. see next point:
- Taxonomy is a fool’s errand. All taxonomies are broken, full stop. Your categories are gonna be completely wrong and everybody’s going to argue over every single thing. There is no such thing as a tree.