Fascinating overview of hierarchical knowledge vs miscellaneous
  [1]https://archive.org/details/Microsoft_Research_Video_103987
  I'm 1/2 way though this - he finished his main speech, and I'm
  very impressed with his overview of social knowledge vs expert
  knowledge, the history of categorization and classification, the
  pluses and minuses of various systems and you really get a good
  feel for The Future from here. Dating from 2007, it's also a
  fantastic historical look in our Internet history... and it's
  interesting how many of these ideas are incorporated invisibly
  into the web as it is in 2016.... and commercialized. I remember
  when the Semantic Web was "the thing" and I wondered where it
  went. I realized it is subsumed now into the monetized web,
  which to me is a step backwards in a big way from this period of
  hope from 2007. It reminds me of how critical non-commercial
  efforts are.

References

  Visible links
  1. https://archive.org/details/Microsoft_Research_Video_103987