Search found 7 matches

by Jay Forrest systems jayforrest.c
Sun Dec 18, 2005 1:47 pm
Forum: SD Mailing List Archive
Topic: SD and other modelling approaches
Replies: 41
Views: 40293

SD and other modelling approaches

Posted by ""Jay Forrest"" <systems@jayforrest.com> Hi Geoff! What a great post! Lots of good things to think about! My work has led me to view part of the ""SD problem"" to over a hundred years of reductionist focus by education - and in particular as a barrie...
by Jay Forrest systems jayforrest.c
Wed Sep 21, 2005 11:45 am
Forum: SD Mailing List Archive
Topic: Non-linear rate equations
Replies: 4
Views: 4468

Non-linear rate equations

Posted by ""Jay Forrest"" <systems@jayforrest.com> >From my perspective there is tremendous difference. First, I see the term complexity including a broad range of phenomena many of which are primarily mathematical relationships without any sense of causality. SD is as much as an...
by Jay Forrest systems jayforrest.c
Fri Aug 19, 2005 11:42 am
Forum: SD Mailing List Archive
Topic: Feedback and Behavior
Replies: 24
Views: 65457

Feedback and Behavior

Posted by ""Jay Forrest"" <systems@jayforrest.com> When Barry Richmond spoke of the growth rate of the stock he was effectively saying the percentage growth rate, and likewise for the flow. Percentages are unitless and therefore there is no unit difference to confuse the comparis...
by Jay Forrest systems jayforrest.c
Wed Aug 17, 2005 5:57 pm
Forum: SD Mailing List Archive
Topic: Feedback and Behavior
Replies: 24
Views: 65457

Feedback and Behavior

Posted by ""Jay Forrest"" <systems@jayforrest.com> In my email regarding the simple, two-element DEC model I inadvertently typed Richardson instead of Richmond. The story related to Barry Richmond and his work for Digital Equipment. I appologize for any confusio nmy typo may have...
by Jay Forrest systems jayforrest.c
Tue Aug 16, 2005 11:58 am
Forum: SD Mailing List Archive
Topic: Feedback and Behavior
Replies: 24
Views: 65457

Feedback and Behavior

Posted by ""Jay Forrest"" <systems@jayforrest.com> Hi Jim! This is probably a bit long and overly familiar for the whole listserve, but there are probably people who will benefit, so here goes. Please feel free to delete the message if you know the DEC/Richardson story. The follo...
by Jay Forrest systems jayforrest.c
Wed Aug 10, 2005 6:45 pm
Forum: SD Mailing List Archive
Topic: Feedback and Behavior
Replies: 24
Views: 65457

Feedback and Behavior

Posted by ""Jay Forrest"" <systems@jayforrest.com> The exceptionally simple Barry Richmond Digital Equipment model of one stock/one flow (customers needing support and computer sales, respectively) strikes me as the near epitome of a system dynamic model even though it has no fee...
by Jay Forrest systems jayforrest.c
Thu Jan 06, 2005 4:44 pm
Forum: SD Mailing List Archive
Topic: Models and Science
Replies: 20
Views: 36517

Models and Science

Posted by ""Jay Forrest"" <systems@jayforrest.com> Great comments, Corey! My personal experiences have led me to embrace both punctuated and phyletic gradualism for I believe they both are operative and each has a place dependent upon the conditions in which the evolution occurs....