From ja+ at cmu.edu Wed Apr 4 17:41:07 2001 From: ja+ at cmu.edu (John Anderson) Date: Wed, 4 Apr 2001 17:41:07 -0400 Subject: Published ACT-R models at last Message-ID: this in email it is available under News from the ACT-R home page (http://act.psy.cmu.edu/). If you do look at it you may gather some appreciation for why it took this long and why I am not emailing it to you. I also came to appreciate that my difficulty in following all the work in ACT-R is not just my age. I would like to thank all of you who sent in contributions. I did some detective work to fill in for a few non responders. If you did not respond and I did not discover your work, then maybe now is the time to respond. If you sent in information (or suspect I might have filled you in) I would urge you to look at the list and check it for accuracy. I know a number of the "submitted" papers may have switched to "in press" and I would appreciate that information. I tried to organize the material categorically where Roman Numeral indicates large domain, number indicates topic of research, and letter model within the topic. If multiple papers describe the same model (or versions of it) I have listed them all with the letter. My category organization is just a first pass and I would appreciate suggestions for a better organization. I may also not have placed your model correctly. I also may not have always chunked the papers correctly into the same model. I would also appreciate feedback on these matters. Finally a couple of additional comments -- I tried to avoid either citing papers at the ACT-R Workshops or chapters from the Atomic Components of Thought because I intend this as evidence of external acceptance of ACT-R models. There were a few occasions where I could not avoid such citations. Again thanks, John -- ========================================================== John R. Anderson Carnegie Mellon University Pittsburgh, PA 15213 Phone: 412-268-2788 Fax: 412-268-2844 email: ja at cmu.edu URL: http://act.psy.cmu.edu/ From tkelley at arl.army.mil Fri Apr 6 11:08:42 2001 From: tkelley at arl.army.mil (Troy Kelley) Date: Fri, 6 Apr 2001 11:08:42 -0400 Subject: ACT-R Parallelism Message-ID: I seem to be a little confused about the parallel aspect of ACT-R P/M. I am working with visual objects and the documentation for ACT-R P/M says that, "the vison module checks the icon to see if there is a feature in the icon that matches the chunk requested by ACT-R. If one existes, a chunk representing that visual location is created and returned to ACT-R in zero time." I guess I also assumed that all chunks returned by ACT-R P/M in zero time would have the same activation levels, but as far as I can tell, they don't. So... if they don't have the same activation levels, then they really are not returned in parallel, because some are more active than others. If they were returned in parallel, they all should have the same activations. So.. do I have to do a match on all the portions of the screen that I want returned as chunks with the same activation? Couldn't I do that without ACT-R P/M? Troy From byrne at rice.edu Mon Apr 9 00:25:23 2001 From: byrne at rice.edu (Mike Byrne) Date: Sun, 8 Apr 2001 23:25:23 -0500 Subject: ACT-R Parallelism Message-ID: > I seem to be a little confused about the parallel aspect of ACT-R > P/M. I am working with visual objects and the documentation for > ACT-R P/M says that, "the vison module checks the icon to see if > there is a feature in the icon that matches the chunk requested > by ACT-R. If one existes, a chunk representing that visual > location is created and returned to ACT-R in zero time." I guess > I also assumed that all chunks returned by ACT-R P/M in zero time > would have the same activation levels, but as far as I can tell, > they don't. It is correct that not all chunks of type VISUAL-LOCATION will have the same activation. This will be a function of what the model is currently attending to, because the slots of the currently-attended visual object are activation sources. Thus the VISUAL-LOCATION chunk associated with that object will have a higher activation than other VISUAL-LOCATION chunks, unless they happen to be stuffed into the goal. > So... if they don't have the same activation levels, then they > really are not returned in parallel, because some are more active > than others. I'm sorry, but I don't understand your logic here. Differential activation of VISUAL-LOCATION chunks doesn't affect the behavior of the Vision Module one iota. That is, the activation level of a VISUAL-LOCATION doesn't affect how rapidly it will be returned with a TIME NOW test. That time is always zero, regardless of the chunk's activation. For example, consider the following production LHS, and assume there are two objects on the screen, one with an x-coordinate of 500 and one with an x-coordinate of 150: =goal> isa example =loc1> isa visual-location time now screen-x 150 =loc2> isa visual-location time now screen-x 500 This production would find (or create) two VISUAL-LOCATION chunks and the total matching time for this production would be zero. This qualifies as parallel in my book, and will happen irrespective of the activations of those chunks, which could be different depending on what's in the goal and what VISUAL-OBJECT is currently attended. Now, if you are retrieving a VISUAL-LOCATION chunk from memory (i.e. doing it *without* a TIME NOW specifier), then you are correct, they will be retrieved serially and will be affected by having differential activation levels. If you omit the TIME NOW specifier, then RPM never gets called; you are simply requesting a pair of retrievals from declarative memory, which works the way it always has. > If they were returned in parallel, they all should have the same > activations. This is simply not true; see my explanation above. > So.. do I have to do a match on all the portions of the screen > that I want returned as chunks with the same activation? > Couldn't I do that without ACT-R P/M? Again, I apologize, but I don't understand what you want here. Could you clarify or re-ask this question? I suspect some code would *really* help here. -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 From tkelley at arl.army.mil Mon Apr 9 10:02:41 2001 From: tkelley at arl.army.mil (Troy Kelley) Date: Mon, 9 Apr 2001 10:02:41 -0400 Subject: ACT-R Parallelism Message-ID: Mike Byrne on 04/09/2001 12:25:23 AM To: Troy Kelley cc: act-r-users at andrew.cmu.edu Subject: Re: ACT-R Parallelism On 01.04.06, Troy Kelley wrote: > I seem to be a little confused about the parallel aspect of ACT-R > P/M. I am working with visual objects and the documentation for > ACT-R P/M says that, "the vison module checks the icon to see if > there is a feature in the icon that matches the chunk requested > by ACT-R. If one existes, a chunk representing that visual > location is created and returned to ACT-R in zero time." I guess > I also assumed that all chunks returned by ACT-R P/M in zero time > would have the same activation levels, but as far as I can tell, > they don't. -It is correct that not all chunks of type VISUAL-LOCATION will have -the same activation. This will be a function of what the model is -currently attending to, because the slots of the currently-attended -visual object are activation sources. Thus the VISUAL-LOCATION -chunk associated with that object will have a higher activation -than other VISUAL-LOCATION chunks, unless they happen to be stuffed -into the goal. > So... if they don't have the same activation levels, then they > really are not returned in parallel, because some are more active > than others. -I'm sorry, but I don't understand your logic here. Differential -activation of VISUAL-LOCATION chunks doesn't affect the behavior of -the Vision Module one iota. That is, the activation level of a -VISUAL-LOCATION doesn't affect how rapidly it will be returned with -a TIME NOW test. That time is always zero, regardless of the -chunk's activation. I understand this.. I guess I was using activation as a measure of parallelism and not just time. -For example, consider the following production LHS, and assume -there are two objects on the screen, one with an x-coordinate of -500 and one with an x-coordinate of 150: -=goal> - isa example -=loc1> - isa visual-location - time now - screen-x 150 -=loc2> - isa visual-location - time now - screen-x 500 - -This production would find (or create) two VISUAL-LOCATION chunks -and the total matching time for this production would be zero. -This qualifies as parallel in my book, and will happen irrespective -of the activations of those chunks, which could be different -depending on what's in the goal and what VISUAL-OBJECT is currently -attended. - -Now, if you are retrieving a VISUAL-LOCATION chunk from memory -(i.e. doing it *without* a TIME NOW specifier), then you are -correct, they will be retrieved serially and will be affected by -having differential activation levels. If you omit the TIME NOW -specifier, then RPM never gets called; you are simply requesting a -pair of retrievals from declarative memory, which works the way it -always has. - > If they were returned in parallel, they all should have the same > activations. -This is simply not true; see my explanation above. I understand your explanation, it just seems to me that if ACT-R P/M perceives multiple items in parallel, the subsequent chunks created by that perception should then have the same time AND activation levels associated with them. > So.. do I have to do a match on all the portions of the screen > that I want returned as chunks with the same activation? > Couldn't I do that without ACT-R P/M? -Again, I apologize, but I don't understand what you want here. -Could you clarify or re-ask this question? I suspect some code -would *really* help here. Actually, the code you present above is exactly what I was talking about here. But again, as you point out above, developing the code in this way will not return chunks with the same activations for the reasons you note above. I got it.. thanks. I guess I need to re-think how I want to construct my model. Troy