QUERY Structural changes and validity
Posted: Thu Oct 04, 2007 6:27 am
Posted by Monte Kietpawpan <kietpawpan@yahoo.com>
Dear all,
Structual validation is key to the success of model development.
However, we have no test to determine whether a given model structure
is stable over the time horizon of interest.
Basic mechanisms may at best represent the ""past structures""
capable of generating the ""past behaviors"". No existing validity
tests serve to check whether the relationships in the real system
will not significantly change in the future--within the time horizon.
If the real structure changes, the model of past behavior would
lack the ability to generate the future behavior. It is therefore
hard believe that SD models are theories, unless the structures
of the aspects being modeled are stable.
SD is not effective in dealing with social problems, of which
the dynamics of the system structures are not yet predictable.
Projection of dynamic behavior, to be successful, calls for the
ability to project the dynamics of the structure, the ability that
the oracle of Delphi posses.
MK
Posted by Monte Kietpawpan <kietpawpan@yahoo.com>
posting date Thu, 4 Oct 2007 02:33:59 -0700 (PDT)
_______________________________________________
Dear all,
Structual validation is key to the success of model development.
However, we have no test to determine whether a given model structure
is stable over the time horizon of interest.
Basic mechanisms may at best represent the ""past structures""
capable of generating the ""past behaviors"". No existing validity
tests serve to check whether the relationships in the real system
will not significantly change in the future--within the time horizon.
If the real structure changes, the model of past behavior would
lack the ability to generate the future behavior. It is therefore
hard believe that SD models are theories, unless the structures
of the aspects being modeled are stable.
SD is not effective in dealing with social problems, of which
the dynamics of the system structures are not yet predictable.
Projection of dynamic behavior, to be successful, calls for the
ability to project the dynamics of the structure, the ability that
the oracle of Delphi posses.
MK
Posted by Monte Kietpawpan <kietpawpan@yahoo.com>
posting date Thu, 4 Oct 2007 02:33:59 -0700 (PDT)
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