<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">here is my 2 cents: a production's utility decreases when that production fires frequently in a sequence of productions that leads to very small rewards. so, all we need to do is make sure we have a "competitive" production there, that is, a production that contributes to getting higher rewards. <DIV><BR class="khtml-block-placeholder"></DIV><DIV>example: a "ride-a-bike" production could lose the competition in favor of a "drive" production if the environment favors speed and safety. however, the "ride-a-bike" production can still win when the environment favors health and losing-weight criteria. </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>ion</DIV><DIV> </DIV><DIV> </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV> <DIV> <BR><DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>On May 15, 2007, at 10:15 AM, Kelley, Troy ((Civ,ARL/HRED)) wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><P><FONT size="2" face="Arial">Classification: <U><B> UNCLASSIFIED</B></U><B></B> </FONT> <BR><FONT size="2" face="Arial">Caveats: NONE</FONT> <BR><FONT size="2" face="Arial"> </FONT> <BR><FONT size="2" face="Arial">ACT-R users,</FONT> </P><P><FONT size="2" face="Arial">I was wondering, and I have never heard of this, if there a concept of production satiation in ACT-R, or someway to implement such a concept? This seems to be a common problem in ACT-R where a production will continue to fire over and over and it is difficult to stop. I understand that the solution is to change the activation of a chunk so that something else will match, but this is difficult to accomplish when the matching chunk keeps increasing in activation, thus causing more matches. I remember a few ACT-R workshops back that someone, I think Richard Young, presented the idea of a production refractory period, and I was wondering if this idea has ever gained any ground? Or are there other ideas of satiation within ACT-R? I am asking this because we are having trouble with our robot performing the same productions over and over. Again, I understand that we need to activate other chunks to cause a different match, but the question is - Where does this increased activation come from? Is this a meta-cognitive function? If there are no “new” stimuli from the outside, what triggers an increase in activation?</FONT></P><P><FONT size="2" face="Arial">Troy D. Kelley</FONT> <BR><FONT size="2" face="Arial">US Army Research Laboratory</FONT> <BR><FONT size="2" face="Arial">Human Research and Engineering Directorate</FONT> <BR><FONT size="2" face="Arial">AMSRD-ARL-HR-SE</FONT> <BR><FONT size="2" face="Arial">Aberdeen, MD, 21005-5425</FONT> <BR><FONT size="2" face="Arial">Ph: 410-278-5869</FONT> <BR><FONT size="2" face="Arial">FAX: 410-278-9523</FONT> </P> <BR><P><FONT size="2" face="Arial"> </FONT> <BR><FONT size="2" face="Arial">Classification: </FONT><U></U><U><B> <FONT size="2" face="Arial">UNCLASSIFIED</FONT></B></U><B></B> <BR><FONT size="2" face="Arial">Caveats: NONE</FONT> </P><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">ACT-R-users mailing list</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="mailto:ACT-R-users@act-r.psy.cmu.edu">ACT-R-users@act-r.psy.cmu.edu</A></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="http://act-r.psy.cmu.edu/mailman/listinfo/act-r-users">http://act-r.psy.cmu.edu/mailman/listinfo/act-r-users</A></DIV> </BLOCKQUOTE></DIV><BR></DIV></DIV></BODY></HTML>