# Scriptapedia/Glossary of terms
## Common Terms
#### Boundary Object

* A tangible representation (e.g. diagram with few words) to illustrate key concepts, actions and the relationships between them, which are accessible and modifiable by all participants (Black & Andersen, 2012)
Balancing Loop
* When the feedback loop's overall effect is to counteract or balance the initial direction of change

#### Community

* There are many definitions of the term "community" (e.g. geographical, by association). In System Dynamics practice, "how we define 'community' determines who is involved, how the issues get framed, who the stakeholders are, how we understand the politics and power, and even what language we use". The process of defining a community is a scientific act. (Hovmand, 2014, p7.)

#### Community Based System Dynamics

* A participatory method for involving communities in the process of understanding and changing systems from the endogenous or feedback perspective of system dynamics, with a focus on developing capabilities within those communities to understand, develop, and critique system dynamics models (Richardson, 2011; Sterman, 2000; Forrester, 1990; as cited in Hovmand, 2014, p.1)

#### Decision Rules

* The policies and protocols specifying how the decision maker processes available information, and thereby takes action (Sterman, 2000)
* "A decision rule specifies which information to take account of, and how to combine the information to arrive at a decision." (Hines & House, 2001)

#### Dynamic hypothesis

* A statement of belief that a particular articulation or model of a system can generate the behavior described in the reference mode. (Hovmand, Sato, Kuhlberg & Chung, 2015)

#### Feedback loop

* A closed loop structure that brings results from past action of the system back to control future action (Forrester, 1990)
* A feedback loop is a circular arrangement of causally connected elements, in which an initial cause propagates around the links of the loop, so that each element has an effect on the next, until the last "feeds back" the effect into the first element of the cycle, resulting in the self-regulation of the entire system (Capra & Luisi, 2014)

#### Group model building

* A process of involving multiple stakeholders that are central to a project in developing an informal or formal model (Hovmand, 2014)
* The process aims to create shared insights, consensus, and motivation for implementing the results (Hovmand, 2014)

#### Mental model

* "A mental model of a dynamic system is a relatively enduring and accessible, but limited, internal conceptual representation of an external system whose structure maintains the perceived structure of that system." (Doyle & Ford, 1998, p. 17)
* An incomplete mental representation of the world around us that is fuzzy and imprecisely stated (Forrester, 1971)

#### Scripts

* A way to document structured small group exercises for GMB (Hovmand, Andersen, Rouwette, Richardson, Rux, & Calhoun, 2012).

#### System dynamics

* System dynamics is the use of informal maps and formal models with computer simulation to uncover and understand endogenous sources of system behavior (Richardson, 2011)

## References

Black, L. J., & Andersen, D. F. (2012). Using visual representations as boundary objects to resolve conflict in collaborative model-building applications. Systems Research and Behavioral Science, 29,194–208.
Capra, F., & Luisi, P. L. (2014). The Systems View of Life: A Unifying Vision. Cambridge University Press.
Doyle, J. K., & Ford, D. N. (1998). Mental models concepts for system dynamics research. System Dynamics Review, 14(1), 3-29.
Forrester, J. W. (1990). Principle of Systems. Waltham, MA: Pegasus Communications. Original edition, 1971.
Hines, J., & House, J. (2001). The source of poor policy: controlling learning drift and premature consensus in human organizations. System Dynamics Review (Wiley), 17(1), 3-32.
Hovmand, P. S., Andersen, D. F., Rouwette, E., Richardson, G. P., Rux, K., & Calhoun, A. (2012). Group model‐building ‘scripts’ as a collaborative planning tool. Systems Research and Behavioral Science, 29(2), 179-193.
Hovmand, P. S. (2014). Community Based System Dynamics. Springer.
Hovmand, P.S., Sato, J., Kuhlberg, J., Chung, S. (2015). Introduction to System Dynamics for Applied Social, Behavioral, and Health Sciences.
Richardson, G. P. (2011). Reflections on the foundations of system dynamics. System Dynamics Review, 7(3), 219-243.
Sterman, J. D. (2000). Business Dynamics: Systems thinking and modeling for a complex world. New York, NY: Irwin McGraw-Hill.

## External Links

System Dynamics Glossary - David Ford