1. Causal loop diagrams
A brief introduction

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Overview of systems thinking analytical
tools

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Example of applying systems thinking
approach
“Overview of system dynamics modeling approach”,
from: Martinez and Richardson (2013)

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What are causal loop diagrams and why
are they useful?
• System dynamics method used to develop a
qualitative conceptualization of a system
• Focus on visualizing internal, mental models
• Facilitates consensus-building and brainstorming
• Can help bring together perspectives and data from
different disciplines
• Complements “traditional” data collection and
analysis

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What are causal loop diagrams and why
are they useful?
• Emphasis on causality and feedback effects
• Causal loop diagrams indicate the sign and direction
of the causality and the type of feedback in the
system
• Communication – NOT simulation
• Whether modeling is appropriate depends on the
question you are trying to solve

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Paina et al (under review) Dual practice
policy in Uganda

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Rwashana et al (2008) Immunization System
CLD

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Causal loop diagram components
• Causality: AB
• Changes in B are caused by changes in A
• Polarity: + or –
• If A and B change in the same direction (either both increase or both
decrease), then polarity is +
• If A and B change in opposite directions, then polarity is –

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Causal loop diagram components
• Feedback loops – a change in the system catalyzes a
cascade through other variables to either reinforce or
balance the initial change.
• Reinforcing feedback loop (vicious or virtuous) – amplifying effect
• Balancing feedback loops – dampening effect

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Causal loop diagram components
• Delays
• The effect that A has on B is delayed (||)
• Balancing loops are often self-regulating, experience delays

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Developing a causal loop diagram
• Qualitative and quantitative data collected using
rigorous methods
• Iterative process for identification of key variables and causal linkages
• E.g. Rwashana’s dynamic systems methodology
• Stage 1 – Problem statement
• Stage 2 – Field studies
• Stage 3 – Model building ***This is where CLDs come in***
• Stage 4 – Case study
• Stage 5&6 – Simulations and Policy analysis
• Participatory modeling and diagram development
• Group model building
• E.g. Peter Hovmand’s work (for example (2012) Hovmand - Group Model-Building
‘Scripts’ as a Collaborative Planning Tool)

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