[ACT-R-users] Extending chunk types

[Dan Bothell]

--On Monday, June 30, 2008 2:43 PM -0400 Chris Sims <simsc at rpi.edu> wrote:

>
>
> The dynamic pattern matching functionality in ACT-R 6 allows one to
> dynamically extend the chunk-type of chunks currently stored in the
> buffers, for example:
>
>
> (P* sample-production
>    =goal>
>       ISA goal-chunk
>       state =state-name
>    ==>
>    =goal>
>       =state-name 42)
>
>
> What I am wondering is:  Is there a way to achieve the same thing
> (dynamically extending a chunk type) when *creating* chunks on the right
> hand side of a production? For example:
>
>
>
> (P* sample-production-2
>    =goal>
>       ISA goal-chunk
>       state =state-name
>    ==>
>    +other-module>
>       ISA other-chunk-type
>       =state-name 42)
>
>
> If I try and run a model containing a production like the above, I get
> the error:
>#| Warning: Invalid slot-name [_____] in call to define-chunk-spec. |#
>
>
> Is there a way to allow this in ACT-R 6?
>
>

Not using a request - at least not directly.  However, you could engineer
a module that could do such a thing using the request parameters.  If
you specify the buffer with some request parameters then you could do
something like this:

 (P* sample-production-2
    =goal>
       ISA goal-chunk
       state =state-name
    ==>
    +other-module>
       ISA other-chunk-type
       :slot-name =state-name
       :slot-value 42)

Then in the module's request function you'd have to pull out the
values for the request parameters, check whether they were valid
slots, if not extend the chunk-type, then create the chunk as
needed.

Dan