[ACT-R-users] New ACT-R 6.0 release

[db30 at andrew.cmu.edu]

ACT-R 6.0 v1.5 [r1451] is now the current version on the ACT-R web site.

Here are the significant changes from the previous version:

- There is now a simulate-retrieval-request command.  It can be called
with a request description as one would provide in a +retrieval>
action in a production.  It will print a simplified version of the
activation trace which results from making that request at the current
time without affecting the retrieval buffer or the declarative
module's state.

Here's an example call after running the count model from unit 1 of
the tutorial:

> (simulate-retrieval-request isa count-order :recently-retrieved t)
Only recently retrieved chunks: (E D C)
Chunk E matches
Chunk D matches
Chunk C matches
Chunk E has the current best activation 0.0
Chunk D matches the current best activation 0.0
Chunk C matches the current best activation 0.0
Chunk C chosen among the chunks with activation 0.0
(C D E)


- Added warnings for several potential problems which the parser finds
among the productions in a model which do not lead to errors in creating
the productions.  These "style" warnings indicate things like a request
for which there is no production that tests such a result or a chunk-type
in a condition which is not requested by any other productions.

There is also a new command called declare-buffer-usage which can be
used in the model definition to suppress some style warnings by indicating
the type and slots of chunks that are being set in buffers by code outside
of the productions and the model definition.

In addition, there is also a new parameter, :style-warnings, which can be
set to nil to suppress all of the style warnings.


- A new system parameter called :starting-parameters has been added.
This system parameter can be set to a list of parameters and values which
are appropriate for use with sgp.  That set of parameters will be applied
at the start of every model definition and at the beginning of every reset.
Essentially, this allows one to change the default values for any of the
parameters.

The recommended way to use :starting-parameters is to put the desired
settings into a .lisp file in the user-loads directory so that it gets
set automatically every time ACT-R is loaded.

Here's an example which would change the starting values for the :esc and
:trace-detail parameters:

(ssp :starting-parameters (:esc t :trace-detail high))


- There is a version of the ACT-R Environment available as an app for
Android devices.  The app and the instructions for installing and using it
are found on the ACT-R website software page under the "Remote Environment"
heading.  This was made possible because of the development of the
AndroWish Tcl/Tk system.  Unfortunately there is not a corresponding Tcl/Tk
system available for iOS.


For details on what else has changed, you can view the commit log on the
ACT-R web site:

<http://act-r.psy.cmu.edu/log/actr6log.txt>

You can also subscribe to a feed to be notified when there are new commits
to the sources:

<http://act-r.psy.cmu.edu/log/actr6feed.xml>

Note that the log and feed locations have changed since the last ACT-R 6
release.


If you have any comments, questions, or problems with this update please
let me know.

Dan