[walterbell]

This could be viewed as layered ontologies, moving from the largest dataset to the most abstracted. Our categories are necessarily personal, but they eventually overlap with generic ones. Presently we don't have good tools to associate personal categories with those of larger datasets, because categories span apps, platforms, orgs & license regimes.

  Classified data
  Corporate data
  Licensed data
  Books
  Open internet
  Personal notes/kb
  Human brain