Causal Diagramming Guide
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Causal Loop Diagrams Causal loop diagrams are used as a tool to aid in Systems Thinking. They are used to represent the structure of a system by showing the relationships between its key parts. This helps in understanding the underlying structures that drive behavior and provides a visual representation with which to communicate that understanding. The diagram generally consists of one or more closed loops that represent cause and effect relationships between variables. This document is designed to give you a high level overview of how to construct a causal loop. In a causal loop diagram, a link is an arrow between two variables that represents a relationship. There are two types of links, “same” and “opposite”. “Same” links are indicated by an s, and represent that a change in the first variable results in a change in the same direction in the second variable. “Opposite” links are indicated by an o, and represent that a change in the first variable results in a change in the opposite direction in the second variable. Guidelines for Drawing Causal Loop Diagrams Guideline Example Selecting Variable Names 1. When choosing a variable name, use nouns. Avoid verbs and action phrases since the action is conveyed in the arrows. For example, “Costs” is better than “Increasing Costs,” since a decrease in Increasing Costs is confusing. The sign of the arrow (“s” for same or “o” for opposite) indicates whether Costs increase or decrease relative to the other variable. Litigation Costs Increasing Costs 2. Variables should be something that can be measured—quantities that can vary over time. It does not make sense to say that “State of Mind” increases or decreases. A term like “Happiness,” on the other hand, can vary. Rewards Happiness State of Mind 3. Choosing the “positive” sense of a variable name is preferable. An increase or decrease in “Growth” is clearer than an increase or decrease in “Contraction.” Demand Growth Contraction Loop Construction 4. For every course of action included in the diagram, think of the possible unintended consequences as well as the expected outcomes. An increase in “Production Pressure” may increase “Production Output,” for example, but it may also increase “Stress” and decrease “Quality.” S---------Production Ouput Production Pressure S---------Stress O--------Quality
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Transcript of Causal Diagramming Guide
Causal Loop DiagramsCausal loop diagrams are used as a tool to aid in Systems Thinking. They are used to representthe structure of a system by showing the relationships between its key parts. This helps inunderstanding the underlying structures that drive behavior and provides a visual representationwith which to communicate that understanding. The diagram generally consists of one or moreclosed loops that represent cause and effect relationships between variables. This document isdesigned to give you a high level overview of how to construct a causal loop.
In a causal loop diagram, a link is an arrow between two variables that represents a relationship.There are two types of links, “same” and “opposite”. “Same” links are indicated by an s, andrepresent that a change in the first variable results in a change in the same direction in the secondvariable. “Opposite” links are indicated by an o, and represent that a change in the first variableresults in a change in the opposite direction in the second variable.
Guidelines for Drawing Causal Loop Diagrams
Guideline Example
Selecting Variable Names1. When choosing a variable name, use nouns.
Avoid verbs and action phrases since the actionis conveyed in the arrows. For example, “Costs”is better than “Increasing Costs,” since a decreasein Increasing Costs is confusing. The sign of thearrow (“s” for same or “o” for opposite) indicateswhether Costs increase or decrease relative to theother variable.
Litigation
CostsIncreasing Costs
2. Variables should be something that can bemeasured—quantities that can vary over time. Itdoes not make sense to say that “State of Mind”increases or decreases. A term like “Happiness,”on the other hand, can vary.
Rewards
HappinessState of Mind
3. Choosing the “positive” sense of a variable nameis preferable. An increase or decrease in“Growth” is clearer than an increase or decreasein “Contraction.”
DemandGrowth
Contraction
Loop Construction4. For every course of action included in the
diagram, think of the possible unintendedconsequences as well as the expected outcomes.An increase in “Production Pressure” mayincrease “Production Output,” for example, but itmay also increase “Stress” and decrease“Quality.”
S---------Production OuputProduction Pressure S---------Stress
O--------Quality
5. All balancing loops are goal-seeking processes.Try to make goals driving the loop explicit. Forexample, Loop B1 may raise questions as to whyincreasing “Quality” would lead to a decrease in“Actions to Improve Quality.” By explicitlyidentifying “Desired Quality” as the goal in LoopB2, we see that at the “Gap in Quality” is reallydriving improvement actions.
Quality
S
B1
Actions toImproveQuality
O
Quality
S
B2
Actions toImproveQuality
O
Gap inQuality
Desired Quality
S
6. Distiguishing between perceived and actualstates, such as “Perceived Quality” vs. “ActualQuality,” is important. Perceptions often lagreality, and mistaking the perceived status forcurrent reality can be misleading and createundesirable results.
Delay
S
S
S
DesiredQuality
PerceivedQuality
R1
ActualQuality
B2
Actions toImproveQuality
O
Gap inQuality
S
7. If there are multiple consequences of a variable,start by lumping them into one term whilefinishing the rest of the loop. For example,“Coping Strategies” can represent many differentways we respond to stress (exercise, meditation,alcohol use, etc).
B2STRESS
O
SCopingStrategies
B
8. There are almost always differing long-term andshort-term consequences of actions. Draw loopswith increasing radius as they progress fromshort-term behavior of using alcohol to combatstress. Loop R1, however, draws out the long-term consequences which will actually increasestress.
R1
B2STRESS O O
B1S
Alcohol Use
S
Productivity Health
General Tips9. If a link between two terms is not clear to others
and requires a lot of explaining, the variablesprobably need to be redefined or an intermediateterm needs to be inserted. “Higher Demand”leading to lower “Quality” may be less obviousthan when “Production Pressure” is inserted inbetween.
ODemand-------------------------------------------Quality
S ODemand---------Production Pressure--------Quality
10. A short-cut to determining whether a loop isbalancing (B) or reinforcing ( R ) is to count thenumber of “o’s” in the loop. An odd number of“o’s” indicates a balancing loop, an even number(or none) means it is a reinforcing loop.CAUTION: After labeling the loop, you shouldalways talk yourself around the loop and makesure the story agrees with your R or B label.
BankFailures
R
Withdrawalsfrom Bank
O
Depositors’Confidence
Solvency
4 “o’s” = R
