Causal Loop Diagrams A Primer Jeff Wasbes Research Works, Inc. jwasbes@researchworks.org jwasbes@gmail.com

Presentation Outline Introduction Mechanics Some tips The what and the why… Mechanics The how… Some tips On good diagramming practice

Introduction What are Causal Loop Diagrams? They are useful for An important tool for representing the feedback structure of systems They are useful for Quickly capturing hypotheses about the causes of dynamics Eliciting and capturing the mental models of individuals or teams Communicating important feedbacks you think might be responsible for a problem

Constructing a Simple Diagram All objects (variables) are nouns All links show causality + Park Maintenance Litter All links have Polarity Constructing a Simple Diagram

A variable increases to an amount more than it would have otherwise been… Net Birth Rate Time A variable decreases to an amount less than it would have otherwise been… Net Birth Rate Time

Constructing a Simple Diagram All objects (variables) are nouns All links show causality + (-) Clean Up Effort Park Maintenance Litter All links have Polarity - All loops have polarity …and the important ones should have names Constructing a Simple Diagram

Refuse Carrying Capacity What story does this diagram tell? + (-) Clean Up Effort + Park Maintenance Litter Show important delays in the system - (+) Overflow + + = Overflow Refuse - Refuse Carrying Capacity

Refuse Carrying Capacity + Use (+) Public Engagement + Perceived Park Condition - + Pressure to Maintain = (-) Clean Up Effort + + Park Maintenance Litter - + (+) Overflow Refuse Removal + + Overflow = Refuse - Refuse Carrying Capacity -

Refuse Carrying Capacity + Use (+) Public Engagement + Minimize Clutter Perceived Park Condition - + Pressure to Maintain Organize your diagram to minimize crossed lines = (-) Clean Up Effort + + Park Maintenance Litter - Model the System, not the Problem + (+) Overflow Refuse Removal Vensim PLE: www.vensim.com A free software for formulating SD models + + Overflow = Refuse - Refuse Carrying Capacity -

For follow-up or questions Jeff Wasbes jwasbes@researchworks.org jwasbes@gmail.com Thank you!