Infovision mandar mutalik desai _ semantic information in social space

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Infovision 2012: Semantics in Social Spaces
A Cognitive Perspective; Mandar Mutalik Desai

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Infovision mandar mutalik desai _ semantic information in social space

  1. 1. Semantics in Social Spaces A Cognitive Perspective Mandar R. Mutalikdesai1,21. Member Technical Staff, Siemens Corporate Research and Technologies 2. Faculty, ISiM, UoM, Mysore Infovision 2012, Bangalore
  2. 2. Agenda What are semantics in social spaces?What do they have to do with cognition? How do we extract them?
  3. 3. Uh huh… Okay… “Social space”“Semantics”, or “meaning” “Cognitive”
  4. 4. So what is a social space? Blog posts, wiki pages, discussionforum posts, Twitter conversations What is common to these?
  5. 5. #1. Content is created by humans in a “non-arbitrary” fashion How is content created then? Cognitive Processes (CPs)
  6. 6. Opinion Argumentation Debate
  7. 7. #2. There is social interaction Comments to blog posts, collaborative editing of wikis, replies to forum postsInteraction between cognitive processes
  8. 8. Sharing excitement Opinion In reply
  9. 9. So what do cognitive processes do? They embed individual world-views into the social space (or into the text) Kobbari Mithai with ice-cream tastes great; Galaxy S3 is a smart phone
  10. 10. Duh… you were supposed to talk about semantics! The individual world-views contain semantic associations A tastes great with B; C is a D; X is an attribute of Y
  11. 11. So these are semantics?But these are individual world-views, remember?Semantics should be applicable across the population!
  12. 12. So, let’s define semantics, shall we? Semantics are nothing but the shared world-view of the population Does the population at large think that the “Galaxy S3” is a “smart phone”?
  13. 13. Let’s just get this out of the way… A semantic association is <concept> <association type> <concept>
  14. 14. So what gives rise to these shared world-views, again? These are aggregate structures, right?Emergent, owing to interaction between CPs
  15. 15. A larger process, then…Socio-cognitive Processes (SCPs)
  16. 16. Sharing excitement Opinion In reply
  17. 17. How do we extract these semantics? They were embedded in the social space by cognitive activities, right? So, isn’t a cognitive approach the most natural for extracting them too, then?
  18. 18. Why not, say, machine learning?They can extract semantics, but can’t explain how they came to be A cognitive approach could!
  19. 19. So, how then?With a methodology that can mimic human cognition (to a degree) Let’s see…
  20. 20. “There is a lala in my kitchen. In the morning, I made some tea in the lala. The lala is made of very highquality stainless steel. The lala has a volume of 2.5 ltrs.” What does “lala” mean?
  21. 21. Why did you conclude so?Due to the way it co-occurs with the other concepts within the same context
  22. 22. Basis for co-occurrence analysis Cognitive Science and Ordinary Language Philosophy
  23. 23. Hebbian Theory of CognitionSemantic memory is formed when concepts are co-activated in the brain “Cells that fire together, wire together”
  24. 24. Who else comes to mind when you think of…
  25. 25. What comes to mind…
  26. 26. What comes to mind…
  27. 27. It’s not just about visual impact Works even when you just think of something The “lala” example!
  28. 28. What comes to mind… Hiroshima Nagasaki
  29. 29. Since the brain mostly “reads” Nagasaki in the same context as Hiroshima… Those two concepts eventually get “wired” together Co-activation of co-occurring concepts
  30. 30. Ordinary Language Philosophy“Meaning is usage” –Ludwig Wittgenstein’s theory
  31. 31. So, co-occurrence lends meaning to concepts… We argue: it also lends meaning to concepts w.r.t. their associations with other concepts
  32. 32. “describe” and “elucidate”… …are synonyms
  33. 33. “Lalbagh”…is an attribute of “Bangalore”
  34. 34. Some co-occurrence basedhypotheses for these associations
  35. 35. a is a synonym of b if They co-occur with a low probability Their co-occurrence neighborhoods are similarThey have similar attributes (again, co-occ based)
  36. 36. A is a set of attributes of b if A and b co-occur with high probabilityA maximizes the probability of guessing b (Akin to the 20-Questions game) (Computing such a set, A, is NP-Hard)
  37. 37. More work in this area at OSL, IIIT-BCo-occurrence hypotheses for semantic associations Experimental analysis of hypotheses Cognitive models for explaining semantics
  38. 38. This work is based on MR Mutalikdesai, Semantics Extraction in Information Spaces using Co-occurrence Analysis,PhD Thesis Draft, Submitted to IIIT-Bangalore, 2012
  39. 39. In collaboration withSrinath Srinivasa, IIIT-Bangalore
  40. 40. Thank you!• Contact Details – mandar.mutalikdesai@siemens.com – mandar@isim.ac.in – Twitter handle: @mrmdesai – http://www.linkedin.com/in/mrmdesai

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