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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>That is a good question.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I think many times as modelers, we need to
make some assumptions about what is happening in the CONTEXT of the overall
task. So, in your example, if you see a fixation for 1500ms, you need to
make some assumptions about what is happening in relationship to the overall
task. Does that fixation represent some critical moment in the flow of
the problem space? Those assumptions would then guide your retrievals or any
other productions that may or may not also include retrievals. So, in
other words, let your knowledge of the task and problem space guide your
assumptions about what is going on during the 1500ms.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
act-r-users-bounces@act-r.psy.cmu.edu
[mailto:act-r-users-bounces@act-r.psy.cmu.edu] <b><span style='font-weight:
bold'>On Behalf Of </span></b>ben.willems@faa.gov<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, February 15, 2006
10:31 PM<br>
<b><span style='font-weight:bold'>To:</span></b> act-r-users@act-r.psy.cmu.edu<br>
<b><span style='font-weight:bold'>Subject:</span></b> [<st1:PersonName w:st="on">ACT-R</st1:PersonName>-users]
Baseline activation strengthening and decay</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
</span></font><font size=2 face=sans-serif><span style='font-size:10.0pt;
font-family:sans-serif'>Please excuse my ignorance, but I am working on the
other side of the cognitive modelers. That is, I run simulations using
human experts in Air Traffic Control and create records of human activity quite
similar to what you call a simulation trace. Ignoring for a moment that
the visual system may be able to process several things within the foveal area
simultaneously, how would you interpret a single 1500msec fixation on an object
in terms of number of retrievals? Does that include a single retrieval or
does it involve cyclic retrievals with a time constant of 50msec for the
retrieval and another 50msec to push the chunk to the goal stack? Or do
you assume that initially there is a retrieval followed by maintaining
activation at a faster cycle time? Do you assume that activation
strengthening occurs independent of the perceptual or motor event that triggers
activation of the chunk? E.g., seeing an aircraft representation vs.
listening to a reference to an aircraft or typing in an identifier for that
aircraft.</span></font> <br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>Ben
Willems<br>
Engineering Research Psychologist<br>
<st1:place w:st="on"><st1:PlaceName w:st="on">William</st1:PlaceName> <st1:PlaceName
w:st="on">J.</st1:PlaceName> <st1:PlaceName w:st="on">Hughes</st1:PlaceName> <st1:PlaceName
w:st="on">Technical</st1:PlaceName> <st1:PlaceType w:st="on">Center</st1:PlaceType></st1:place><br>
NAS Human Factors Group (ACB-220)<br>
Building 28<br>
<st1:place w:st="on"><st1:City w:st="on">Atlantic City International Airport</st1:City>,
<st1:State w:st="on">NJ</st1:State> <st1:PostalCode w:st="on">08405</st1:PostalCode></st1:place><br>
<st1:country-region w:st="on"><st1:place w:st="on">USA</st1:place></st1:country-region><br>
Phone: 609-485-4191<br>
Fax: 609-485-6218<br>
E-mail: Ben.Willems@faa.gov</span></font><o:p></o:p></p>
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