Scriptapedia/Causal Mapping with Seed Structure

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Causal Mapping with Seed Structure

This script is used to elicit causal structures at the beginning of a group model building process when there is an interest in quickly illustrating how a focal problem or situation could involve a system of interacting feedback loops.


Best practices

Primary nature of group task



Preparation time: 180 minutes

Time required during session: 90 minutes

Follow-up time: 90 minutes


  1. Data projector
  2. Computer running modeling software (e.g., Vensim)
  3. Recorder's materials
  4. Flip charts with key words posted in the room


Stock-flow seed structure from prior work with core modeling team


Causal map of reinforcing and balancing feedback loops that identify variables and structures related to a focal problem


  • Modeler with expertise in system dynamics modeling who can draw diagrams in real time
  • Facilitator familiar with the situation and language used by participants to discuss the problem, and strong group facilitation skills appropriate to the culture of participation
  • Recorders (2) with some exposure to system dynamics and/or familiarity with the context of the issue


  1. The modeler, who is sitting with a laptop connected to a data projector, and the facilitator are at the front of the room. The modeler could also be drawing the structure by hand on a white board or paper, as long as it is visible to the entire group.
  2. The facilitator begins by explaining, “We’re going to spend the next 90 minutes or so doing a causal mapping exercise [on the previously identified issue]."
  3. The modeler explains that the diagram that will result from this will be available to them. The modeler then introduces the seed structure with the stock and flows.
  4. If changes are suggested or needed, the facilitator affirms the changes while the modeler captures the changes.
  5. The facilitator then explains that participants can talk about their own experience or what they see in their family or community.
  6. The recorders document working definitions used for key words.
  7. The facilitator then asks questions that help identify impact and causal relations between identified key variables.
  8. As someone suggests something, the modeler draws the link on the model in front of the room. The facilitator and modeler will then encourage participants to add variables and relationships. The modeler tries to get things recorded using exactly the same terms as the participants.
  9. Meanwhile, the recorders are taking notes on the variables named, relationships being described, and quotes or stories that help put some context around the story. If necessary, the recorder uses the number chart developed earlier to help identify who is saying what.
  10. The modeler explains the notation as the structure is drawn on the board. This includes arrows, polarity (‘+’, ‘-‘), and feedback loops as they appear in the diagram.
  11. The recorders write down relationships and should, as much as possible, use arrows in causal chains with ‘+’ and ‘–‘ signs to indicate the direction of the relationship. A ‘+’ sign indicates that increasing one leads to an increase in the other, and a decrease in one leads to a decrease in the other. A ‘-‘ sign indicates an opposite effect where increasing one leads to a decrease in the other, and a decrease in one leads to an increase in the other.
  12. The recorders should avoid interrupting the flow of the conversation between participants and generally avoid asking clarifying questions or adding comments. They should simply make a note of the questions or comments in the margins and distinguish them from things that participants said, such as by using an asterisk (*) symbol.
  13. The modeler will interject when the first feedback loop has been formed.
  14. If the group begins to slow down and there is time, or no feedback loop has been formed, the modeler will ask if there are any relationships between the identified variables that have not been discussed. Doing this will help create loops that might otherwise have been missed.
  15. The process continues until there are about 5 minutes left in the exercise, at which point the modeler points out, “We’ve only spent a little time, less than 90 minutes, coming up with some of these relationships and already it is looking pretty complicated.” However, this is still much simpler than the reality they are trying to manage in practice and research. Ask if there are any other important variables or relationships that haven't been described.

Evaluation Criteria

  • Energized participants interested in more modeling
  • A causal map with multiple feedback loops
  • Recognizing that there is a feedback system producing the reported behavior
Example 1
Example 2 (pictorial)




This particular script was first based on an activity conducted with Save the Children UK, Mongolia in 2006 and was formalized as part of the Missouri Transformation Project. Lune-Reyes et al. (2006) describe a similar activity.


Revised 2013 by Peter Hovmand to reflect current practices.


Luna-Reyes, L. F., Martinez-Moyano, I. J., Pardo, T. A., Cresswell, A. M., Andersen, D. F., & Richardson, G. P. (2006). Anatomy of a group model-building intervention: Building dynamic theory from case study research. System Dynamics Review, 22(4), 291–320.


This exercise is based on a more general, common activity in system dynamics modeling that follows from using system dynamics modeling software in classrooms, workshops, and group model building. The exercise works well for quickly (1) conveying the idea that systems are complex, (2) introducing the language of system dynamics (e.g., balancing and reinforcing feedback loops, stocks and flows), and (3) grounding the emerging model in participants’ language. The exercise can be conducted with large groups up to about 50 or 60 individuals, but participation tends to be limited after the group size exceeds 20 individuals. The design of the seed structure is critical and should be piloted before attempting to conduct this exercise.

  • Help participants use thumbs up and thumbs down motions to help figure out polarity.
  • Explain that "+" and "-" don't mean good and bad, or positive and negative, but rather same and different, or direct and inverse.
  • There are two ways to check if a loop is balancing or reinforcing:
    • When you talk through the loop, if you end moving the same direction that you started = Reinforcing
    • Even number of “-” signs = Reinforcing
  • Use an example that resonates most with the group - the Chicken and Egg is just an option!