When endeavoring to develop an understanding of the nature of something it is generally useful to create a model of some type to aid in surfacing that understanding.

This common archetype of systems that include relapse or recidivism allows exploration of the unintended effects of increasing upstream capacity and swamping downstream capacity. The increase in the relapse rate eventually returns to swamp upstream capacity as well. A social welfare example, based on a TANF case study, from How Small System Dynamics Models Can Help the Policy Process. N. Ghaffarzadegan, J. Lyneis, GP Richardson. System Dynamics Review 27,1 (2011) 22-44 Conference version at http://bit.ly/HlxtZj

The interaction of a population of Moose and Wolves.

While these pictures represent very different things there is a common essence.

What do activities of these images have in common?

All the following have a common characteristic.

All the following have a common characteristic.

This Romeo and Juliet Model was adapted by Geoff McDonnell from Michael J Radzicki (1993) Dyadic processes, tempestuous relationships, and system dynamics, System Dynamic Rev. 9 (1) :79-94

The interaction of a population of Moose and Wolves.

The purpose of this model is to have the user change the value of stocks, flows and converters to experience a variety of different graphical results. Understanding this generic model is important pre-requisite to learning about intravenous drugs in the body, radioactivity, self-esteem, water flowing from a drain and many other basic natural systems.

There's actually more to filling a swimming pool with water than you might realize.

The interaction of a population of Moose and Wolves.

While these pictures represent very different things there is a common essence.

While these pictures represent very different things there is a common essence.

The interaction of a population of Moose and Wolves.

All the following have a common characteristic.

This model is derived from the paper "Nobody Ever Gets Credit for Fixing Problems that Never Happened: Creating and Sustaining Process Improvement" by Nelson P. Repenning and John D Sterman. See Insight 752 for a causal loop version of this model.

Consider the following "Sustaining the Forest" model intended to provide another example of how unexpected the behavior of a web of extended interactions can be.

There are limits to what one can infer from a qualitative model.

All you wanted to do was put a bird feeder in your yard to attract birds and make for a more pleasant morning. And...

This model is derived from the paper "Nobody Ever Gets Credit for Fixing Problems that Never Happened: Creating and Sustaining Process Improvement" by Nelson P. Repenning and John D Sterman. See Insight 752 for a causal loop version of this model.

Consider the following "Sustaining the Forest" model intended to provide another example of how unexpected the behavior of a web of extended interactions can be.