# Causal Loop Diagrams
A way of modeling a system - very much a systems-thinking mental model
1. Draw which parts of a system affect which other parts
2. Annotate whether the link increases (+) or decreases (-) the part
3. You can simplify links in series with the following rules
1. Two of the same signs in series => (+)
1. To write out the logic here: if A increases B which increase C, A increases C. If A decreases B which decreases C. A increases C.
2. Two of the opposite signs in series => (-)
1. If A increases B which decreases C, A decreases C.
2. If A decreases B which increases C, A decreases C
4. Look for loops
* opposite signs are “balancing” which are the same concept as [[Negative feedback loops]] in [[Control Theory]] and [[Circuit Diagrams]]
* The same sign are “reenforcing” which are the same concept as [[Positive feedback loops]] in [[Control Theory]] and [[Circuit Diagrams]]
Parts connected in series roughly act like [[And operators]] in [[Formal Logic]] which also acts like parts in series in [[Circuit Diagrams]].
## Related
[[Control Theory]]
[[Circuit Diagrams]]
[[Formal Logic]]
## References
[[Causal Loop Diagrams]]
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