Language Issues
control flow:
- imperative approach: flow diagrams
- declarative approach: object dependencies, pattern-matching
level of procedural abstraction:
- high level: not possible to maintain and write entire program in given language; e.g. software engineering tools, scientific visualization
- low level: express fine-grained logic but no means for generalization; e.g. domain-specific visual languages
data abstraction:
- consistency with visual paradigm: no underlying textual representation
- visual definition of abstract data types
- objects resulting from such definitions are visual