ACT-R/PM in press

[Mike Byrne]

Two papers ACT-R/PM papers are now slated to be "in press," so now
there are journal article references for RPM.  They are:

Byrne, M. D., & Anderson, J. R. (in press). Serial modules in
parallel: The psychological refractory period and perfect
time-sharing. To appear in _Psychological Review_.

Byrne, M. D., (in press). ACT-R/PM and menu selection: Applying a
cognitive architecture to HCI. To appear in _International Journal
of Human-Computer Studies_.

You can download PDF versions from my publications Web page: 

http://chil.rice.edu/byrne/pubs.html


Abstracts follow:


Serial modules in parallel
--------------------------
This paper describes an integrated theory of cognition, perception,
and action called ACT-R/PM.  The theory consists of the ACT-R
production system as the underlying theory of cognition and a set
of perceptual-motor modules much like those found in EPIC (Meyer &
Kieras, 1997a, 1997b).  Cognition and each of the perceptual-motor
modules are essentially serial, but they all run in parallel with
one another.  This extended version of ACT-R can model simple dual
tasks such as the psychological refractory period, including subtle
results previously explained with EPIC.  The principal difference
between the theories is that EPIC claims productions implementing
central cognition can fire in parallel whereas ACT-R/PM claims they
fire serially.  Therefore, three experiments were run employing
novel dual-task situations with more demanding cognitive
requirements (e.g. arithmetic).  The data indicate that the
cognitive processing for the two tasks in these experiments was not
overlapping.  The true power of ACT-R/ PM is demonstrated with
models of these experiments.  In particular, ACT-R's
activation-based retrieval processes are critical in accounting for
the timing of these tasks and for explaining the slow-down in
performance in a dual-task situation.


ACT-R/PM and menu selection
---------------------------
Understanding the interaction of a user with a designed device such
as a GUI requires clear understanding of three components: the
cognitive, perceptual, and motor capabilities of the user, the task
to be accomplished, and the artifact used to accomplish the task. 
Computational modeling systems which enable serious consideration
all of these constraints have only recently begun to emerge.  One
such system is ACT-R/PM, which is described in detail.  ACT-R/PM is
a production system architecture that has been augmented with a set
of perceptual-motor modules designed to enable the detailed
modeling of interactive tasks.  Nilsen's (1991) random menu
selection task serves two goals: to illustrate the promise of this
system and to help further our understanding of the processes
underlying menu selection and visual search.  Nilsen9s original
study,  two earlier models of the task, and recent eye-tracking
data are all considered.  Drawing from the best properties of the
previous models considered and guided by  information from the
eye-tracking experiment, a series of new models of random menu
selection were constructed using ACT-R/PM.  The final model
provides a zero-parameter fit to the data that does an excellent,
though not perfect, job of capturing the data. 


Thanks to all of you who helped make these papers happen!
-Mike

===========================================================
Mike Byrne, Ph.D.                             byrne at acm.org
Assistant Professor, Psychology Department
Rice University, MS-25          http://chil.rice.edu/byrne/
6100 Main Street                      +1 713-348-3770 voice
Houston, TX  77005-1892                 +1 713-348-5221 fax