qualitative data, fuzzy sets and table functions in
Posted: Tue Apr 02, 2002 9:59 am
Gebhard Wulfhorst asks three questions:
1) What kind of knowledge and experience exists in integrating qualitative
data, estimated values or fuzzy information in the structure of differential
equations between stock and flow?
2) How can table functions be specified in order to point out this level of
information?
3) How do you avoid black box correlations in these cases?
Jay Forresters Industrial Dynamics describes the processes of estimating
constants and their cousin, the table function. And John Stermans Business
Dynamics responds to these questions in Chapter 14, Formulating Nonlinear
Relationships. His discussion of theory is illustrated with practical
examples of how expert modelers have tackled at least the first two
questions.
The third question is about communication with the people who help to build
the model and who use the model. If the model builders document sources for
table function estimates in the form taught by Professors Forrester and
Sterman, model users arent likely to feel that table functions are black
boxes. There are several books and journal articles on group model-building
that tackle the full disclosure problem. For example, John Morecroft and
John Sterman edited a volume of modeling experiences, Modeling for Learning
Organizations, with many practical suggestions for keeping individuals and
groups informed and aligned in the processes of model development,
formulation and implementation.
Jim Thompson
From: "Thompson, Jim A-136" <Jim.Thompson@CIGNA.COM>
Medical Cost Analysis & Forecasting
CIGNA Information Management
900 Cottage Grove Road, A136
Hartford, CT 06152
1) What kind of knowledge and experience exists in integrating qualitative
data, estimated values or fuzzy information in the structure of differential
equations between stock and flow?
2) How can table functions be specified in order to point out this level of
information?
3) How do you avoid black box correlations in these cases?
Jay Forresters Industrial Dynamics describes the processes of estimating
constants and their cousin, the table function. And John Stermans Business
Dynamics responds to these questions in Chapter 14, Formulating Nonlinear
Relationships. His discussion of theory is illustrated with practical
examples of how expert modelers have tackled at least the first two
questions.
The third question is about communication with the people who help to build
the model and who use the model. If the model builders document sources for
table function estimates in the form taught by Professors Forrester and
Sterman, model users arent likely to feel that table functions are black
boxes. There are several books and journal articles on group model-building
that tackle the full disclosure problem. For example, John Morecroft and
John Sterman edited a volume of modeling experiences, Modeling for Learning
Organizations, with many practical suggestions for keeping individuals and
groups informed and aligned in the processes of model development,
formulation and implementation.
Jim Thompson
From: "Thompson, Jim A-136" <Jim.Thompson@CIGNA.COM>
Medical Cost Analysis & Forecasting
CIGNA Information Management
900 Cottage Grove Road, A136
Hartford, CT 06152