Levels in Abstract Models

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Bill Braun
Senior Member
Posts: 73
Joined: Fri Mar 29, 2002 3:39 am

Levels in Abstract Models

Post by Bill Braun »

I am looking for guidance and/or references for identifying levels, rates
and auxiliaries in models that deal with largely abstract concepts. This
could be mental models or changes in organizational culture or norms.

In particular, I am exploring the dynamics of population based health (not
health care). I recently finished rereading Urban Dynamics. As I look at
health, and thinking of Enterprise, Housing and People as a conceptual
example for a health model, I find it difficult to make the connection
between the concrete/tangible levels used in Urban Dynamics (inclusive of
the New, Mature and Declining Enterprise levels and the Premium, Worker and
Underemployed Housing levels) and levels that are more abstract, such as
Health Status.

Apart from determining whether they are levels, flows or auxiliaries, Ive
identified these influences as the factors influencing health: Physical
Environment, PychoSocial Environment, Personal Habits (Lifestyle),
Intervention (Healthcare), Community Practices and Infrastructure (i.e.,
Public Health, e.g., immunizations and water treatment), and Age.

For example, if Physical Environment is a level, what constitutes the stuff
that is being integrated? Toxins, or the frequency of climatic or
geological disasters? One of those variables can be influenced by policy
and one cannot; both impact health. Does this suggest two separate levels
that are treated differently? Should there be a higher order such as Health
Debilitating, Health Sustaining and Health Improving with flows between them?

Regards Personal Habits, what is accumulating? for example, is it the net
between the frequency and quantity of fatty foods and the frequency and
quantity of exercise?

Ive read through Forresters chapter on Policies, Decisions and
Information Sources in Morecroft and Stermans "Modeling for Learning
Organizations". That was helpful in one regard and puzzling (respect to
population based health) in another regard.

Suggestions and/or references and citations would be appreciated, or
perhaps a model that is largely abstract that I could study.

Many thanks,

Bill Braun
From: Bill Braun <medprac@hlthsys.com>
Khalid Saeed
Senior Member
Posts: 79
Joined: Fri Mar 29, 2002 3:39 am

Levels in Abstract Models

Post by Khalid Saeed »

Following two papers, among many others, are good examples of modeling
non-quantifiable abstract concepts:

Saeed, K. 1998. Maintaining Professional Competence in Innovation
Organizations. Human Systems Management. 17(1): 69-87.

Saeed, K. 1990. Government Support of Economic Agendas in Developing
Countries: A Behavioral Model. World Development. 18(6).

Khalid Saeed
saeed@wpi.edu

_____________________________________
Khalid Saeed
Professor and Department Head
Social Science and Policy Studies
W. P. I., 100 Institute Road
Worcester, MA 01609, USA

Ph: 508-831-5563; fax: 508-831-5896
email: saeed@wpi.edu

SSPS Dept: http://www.wpi.edu/Academics/Depts/SSPS/
Paul Newton
Junior Member
Posts: 2
Joined: Fri Mar 29, 2002 3:39 am

Levels in Abstract Models

Post by Paul Newton »

Bill,

In addition to the papers that Khalid Saeed recommended, I recommend the
following paper as a good example of modeling a non-quantifiable abstract
concept:

Homer, J. B. 1985. Worker Burnout: A Dynamic Model with Implications for
Prevention and Control. "System Dynamics Review" 7(1): 68-86.

Paul Newton
From: Paul Newton <
paulnewton@attglobal.net>

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Paul Newton
667 St. James Circle, Green Bay, WI 54311
(607) 255-5230 (@ Cornell through sometime in June, 2000) &
(920) 465-1896 (permanent in Green Bay), e-fax: (815) 461-9636,
email: paulnewton@attglobal.net
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Tom Fiddaman
Senior Member
Posts: 55
Joined: Fri Mar 29, 2002 3:39 am

Levels in Abstract Models

Post by Tom Fiddaman »

Jack Homers Burnout model is included in the sample models distributed
with Vensim. You can also download a copy from my model library (
http://home.earthlink.net/~tomfid ); it can be run with Vensim PLE.

Tom

****************************************************
Thomas Fiddaman, Ph.D.
Ventana Systems http://www.vensim.com
8105 SE Nelson Road Tel (253) 851-0124
Olalla, WA 98359 Fax (253) 851-0125
Tom@Vensim.com http://home.earthlink.net/~tomfid
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Bill Braun
Senior Member
Posts: 73
Joined: Fri Mar 29, 2002 3:39 am

Levels in Abstract Models

Post by Bill Braun »

In March I asked for some direction on how to approach and treat levels
that are abstract (e.g., attitudes) rather than tangible (e.g., inventory).
I received a number of replies. This is a compiled list of what I
eventually found and studied.

Many thanks to Paul Newton and Tom Fiddaman for their suggestions. I
particularly wish to thank Kalid Saeed who made two of his articles
available and to Jay Forrester for his private correspondence that was most
helpful.

"The Unavoidable A Priori", Donella H. Meadows, Elements of the System
Dynamics Method, Jorgen Randers, ed. This is an excellent set of
observations on SD for many reasons. I highly recommend it.

"Guidelines for Model Conceptualization", Jorgen Randers, Elements of the
System Dynamics Method, Jorgen Randers, ed. Specifically, the discussion of
reference mode was very helpful.

George Richardson, Feedback Thought in Social Science and Systems Theory,
Chapter Three, "Two Feedback Threads". Much of the chapter exceeds what I
was looking for; nonetheless, when considered with the other reading it was
very helpful.

"Policies, Decisions, and Information Sources for Modeling", Jay Forrester,
Modeling for Learning organizations, John Morecroft and John Sterman, ed.

George Richardson and Alexander Pugh, Introduction to System Dynamics
Modeling with DYNAMO, Section 4.3, "What is a Level?". An excellent
discussion.


Thank you again to all who provided guidance and assistance.

Bill Braun
From: Bill Braun <medprac@hlthsys.com>
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