SHRDLU
en.wikipedia.org
SHRDLU
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Re: SHRDLU
#2More information including images of graphical 3-D version: http://hci.stanford.edu/winograd/shrdlu/
and an online version of part of the system http://www.grammaticalframework.org/~peter/shrdlite/shrdlite...
Re: SHRDLU
#3Related: http://commonsensereasoning.org/winograd.html
Page 290 of the dissertation [1] discusses ambiguity in words and phrases. The Winograd Schema challenge as defined by Hector Levesque poses questions like "The ball could not fit through the hole because 'it' was too big. What was too big?"
These questions are obvious to humans, but difficult for computer programs to answer, because "it" may refer to multiple objects. If SHRDLU gets confused, it may ask for clarifications from the human, or make its best guess and assume that "it" refers to the green cube rather than the blue pyramid.
Re: SHRDLU
#4Just that abbreviation brings back good memories to a CS practicum in which we needed to write a language parser and virtual world manager in Prolog. Especially building the memory functionality -- "place the blue ball on top of the red cube", "move the ball to the right" -- was fun, taking into account the vague reference to earlier objects and possible/allowed movements. Man, I need to find that code just to enjoy the memories...
Re: SHRDLU
#5More information including images of graphical 3-D version: http://hci.stanford.edu/winograd/shrdlu/ and an online version of part of the system http://www.grammaticalframework.org/~peter/shrdlite/shrdlite...
Thanks—we changed the url to that first one from http://en.wikipedia.org/wiki/SHRDLU.
Re: SHRDLU
#6It is very interesting to (re)discover software like that!
IMO lot of things have been invented in the 70s and we always reinvent the wheel!
Re: SHRDLU
#7Maybe it's also good idea to revisit the reason why these systems are not widely in use. They all operate under so called "closed-world" assumptions. It means that the knowledge about the world is very limited.
Once the limitation is lifted the system has to deal with non-monotonic reasoning (http://en.wikipedia.org/wiki/Non-monotonic_logic) and that leads to multiple inheritance problem (http://en.wikipedia.org/wiki/Multiple_inheritance). Unfortunately, the multiple inheritance problem has, so far, only NP-hard solutions (http://ijcai.org/Past%20Proceedings/IJCAI-89-VOL-2/PDF/047.p...). [EDIT: think of a command "eggs are in a fridge"; to find eggs in a fridge you need to know that they are inside a container; you need to know its shape and how to open it; if your software knows that and inherits this knowledge each time when asked for eggs, then it will brake when the eggs are not in the box.]
We are in need of software that deals with large networks of human knowledge. Then we can take SHRDLU to the next level. Otherwise we are stuck with Will Smith movie (http://www.imdb.com/title/tt0343818/).
[EDIT2: there are many theoretical "suggestions" but very little software or practical internet applications]
Re: SHRDLU
#8The source code is very well commented, a high quality piece of engineering.
Re: SHRDLU
#9Maybe it's also good idea to revisit the reason why these systems are not widely in use. They all operate under so called "closed-world" assumptions. It means that the knowledge about the world is very limited. Once the limitation is lifted the system has to deal with non-monotonic reasoning ( http://en.wikipedia.org/wiki/Non-monotonic_logic ) and that leads to multiple inheritance problem ( http://en.wikipedia.org/w…
Why can't that problem be solved by simply creating multiple closed worlds, each with a set of initial conditions, similar to a text adventure (eg. "you are standing in a room. Some eggs are resting on the counter top" etc.)
Re: SHRDLU
#10Maybe it's also good idea to revisit the reason why these systems are not widely in use. They all operate under so called "closed-world" assumptions. It means that the knowledge about the world is very limited. Once the limitation is lifted the system has to deal with non-monotonic reasoning ( http://en.wikipedia.org/wiki/Non-monotonic_logic ) and that leads to multiple inheritance problem ( http://en.wikipedia.org/w…
Although it's not a discussion of the specific limitations of a closed-world system, Jeff Hawkin's 2004 book "On Intelligence" touches on many of the shortcomings of such systems, especially with respect to general problem solving and understanding. Even if you don't agree with all of his ideas, I would still recommend reading it if you have an interest in computer understanding.