[comp.ai] scripts revisted...

gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) (03/29/91)

Read Shank's readings on scripts.  Have a question though on the restaurant
script:

What if one develops many scripts for all the restaurants for a particular
city but the system suggests all the restaurants irregardless of the 
inputs provided?

I've read some criticisms of the script paradigm.  One by Hubert Dreyfus 
(sorry if I got the name wrong), a noted critic of AI, he suggests the
script approach is to ad hoc in its representation.  Can someone elaborate
on this?

I think that the script representation can't handle unexpected scenarios and
is only designed for stereotypical situations.

Thanks for the info!

epstein@sunc4.cs.uiuc.edu (Milt Epstein) (04/01/91)

In <9103290133.AA27890@enuxha.eas.asu.edu> gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) writes:

>Read Shank's readings on scripts.  Have a question though on the restaurant
>script:
>
>What if one develops many scripts for all the restaurants for a particular
>city but the system suggests all the restaurants irregardless of the 
>inputs provided?

You might want to look at some of Schank's later work on MOPs (memory
organization packets) -- Janet Kolodner also did a lot of work on
them.  The main idea was that episodes were organized hierarchically
from general to specific (so that, for example, general MOPs/scripts
for restaurants were above those for specific restaurants), and common
features were stored at the appropriate level, and distinguishing
features were used to index distinct MOPs.  If there's enough
indexing, the system will be able to pick an appropriate MOP/script
according to the features of the current situation.  Kolodner's system
was called CYRUS and she has a book on it (whose name I cannot
remember -- perhaps something like "The Structure and Organization of
Episodic Memory").  Very interesting stuff, and the basis for much of
the work today on case-based reasoning systems.


>I've read some criticisms of the script paradigm.  One by Hubert Dreyfus 
>(sorry if I got the name wrong), a noted critic of AI, he suggests the
>script approach is to ad hoc in its representation.  Can someone elaborate
>on this?

I'm not real sure about this.  Perhaps he meant that you could fill in
the script with anything, so it didn't have formal or consistent
underpinnings.  But Schank et al would probably argue that this is a
"feature" and corresponds to how people do it -- since everyone's
impressions of restaurants (or whatever) are different and are formed
by experience.


>I think that the script representation can't handle unexpected scenarios and
>is only designed for stereotypical situations.

I believe Schank clearly indicates that scripts are supposed to
represent stereotypical situations, and that he introduced plans and
goals and themes to account for more general scenarios.


-- 
Milt Epstein
Department of Computer Science
University of Illinois
epstein@cs.uiuc.edu

bill@gistdev.gist.com (Bill Busen) (04/02/91)

gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) writes:

>I think that the script representation can't handle unexpected scenarios and
>is only designed for stereotypical situations.

An approach that Gerald DeJong suggested to me to handle this is "script
switching and interaction" schema.  Let's say a fire breaks out in a
restaurant.  The restaurant script may say that you normally eat and pay before
leaving, and draw unkind inferences if you don't.  What you want is to
recognize that you are entering a multiple-script situation, determine that
the "fire" script bears more immediately on your goals (this approach requires
that you relate scripts to goals), and switch scripts before you burn your
posterior.  To me, this has the advantage of fairly well modelling what people
in fact do.

The strength of it is that the myriad unexpected situations that can occur
while tooling along in a script do fall into classifiable (scriptable) areas.