Understanding Commonsense Knowledge

 

UNDERSTANDING COMMONSENSE KNOWLEDGE

We all have pieces of commonsense knowledge within us. But we also have an understanding of them - we know, in crude terms, the why and how - the working - of the processes related to them. This constitutes commonsense reasoning behind the piece of commonsense knowledge, and which (the reasoning) is invisible/unsaid too. Every piece of commonsense knowledge is accompanied by a commonsense understanding of it, which lies in a piece of commonsense reasoning behind it. 

Machines don't have an understanding of the commonsense knowledge pieces in the KB. They don't know why and how ovens bake or scissors cut or pulling tears or eating puts something in the stomach - in crude terms. This is required for commonsense reasoning. 

We need to thus represent the mechanism and thus the crude steps in the workings of eating, cutting, baking, tearing etc.

This will substitute writing hundreds of pieces of varied knowledge.

Consider this example : Mary had a sore mouth. So Jack didn't give her the chicken. 

The CYC system can infer here, but in terms like : if you have a sore mouth, then you avoid eating food. But it doesn't have a “real understanding” of why what it is outputting is true.

Systems which understand KB pieces can “explain” this too (not just in discrete knowledge steps) but by pointing out the stage at which this problem lies, in the relevant process. 

If you have a commonsensically laid-out process in the KB, prepared by filling in the requisite boxes of ‘STATE -> ACTION -> STATE -> ACTION -> …..’ you will have, for say, eating, something like - 

(S)           (A)       (S)         (A)           (S)        (A)             (S)           (A)        (S)        (A)    (S)

Hold food in -> Open -> mouth open -> put held       -> food inside ->close mouth-> mouthclosed  -> apply force->food enters->none->food enters

Hand                Mouth                           food in mouth    mouth                                 with food inside    to swallow     food-pipe                  stomach

Now, the system can diagnose the knowledge piece (sore mouth implies avoid food) by pointing out the stage (4) - sore mouth closed with food inside - as the reason or problem-space, which gives an understanding and “feel” of the commonsense knowledge piece, and which also comprises a kid’s understanding. 

This also automatically creates varied commonsense knowledge pieces like - the relative order of the actions, states and ‘actions and states mixed’, and internal cause-effect pairs in the process. This provides a rich substrate for the system to do commonsense reasoning of various kinds on the situation.