Introduction to Connection Circles

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SWBAT define a problem, identify the variables that change over time, describe how the variables contribute to the problem and create a connection circle that connects the variables to the problem.

Big Idea

Students learn a simple protocol for identifying the relationships that exist in complex systems.

Getting Started

One of the tools in systems dynamics is a connection circle. These serve to help create a visual which focuses on the problem and uncover the causes.

In this lesson you will guide students through the analysis of a factual story of ecological disruption. Students will  summarize the problem presented in the story, identify the variables in the story that change over time and create a simple behavior over time graph for each variable. Next you will have them position those terms around a large circle drawn in the center of a piece of paper. You will then guide them to making connections across the circle from variable to variable to show the relationships that caused change to occur. Once this is completed  students will look for feedback loops within this circle that might be reinforcing or balancing.


  • Copies of the story The Case of The Twin Islands
  • BOTG worksheet
  • Connection Circle Template 

The steps to build a connection circle are outlined below.

  1. Draw a circle of the behavior-over-time graph (BOTGs). This should initially be limited to 5-10.
  2. Graph the elements that change in the story on the BOTGs which should be:
    • relevant to the main idea of the story or text  
    • dynamic, for instance their values change
    • noun or noun phrases, preferably.
  3. Identify the causality: elements that cause other elements to change (increase or decrease).
    • Find a direct cause-and-effect relationship
    • draw an arrow from the cause element to the effect element
    • label the arrowhead.
    • use a “+” or an “s” to indicate the variable changes in the same direction (both go up or both go down) or a change in a variable adds to the following variable.
    • Use “-“ or “o” to indicate that the variable change is in the opposite direction or a change in one variable subtracts from the following variable.
  4. Continue this process until you have added all of your causal arrows.
  5. Identify and analyze feedback relationships in the circle. These relationships can be shown as causal loop diagrams.
  6. Mentally simulate your "model" (tell/retell the story).
  7. Consider leverage points in the system.
    • What elements have the greatest number of arrows coming out from them?
    • How might feedback loops you identified influence the system as a whole?

 Adapted from The Shape of Change, Al Ticotsky, Rob Quaden and Deb Lyneis


5 minutes

 I start this lesson by handing out copies of the story The Case of the Twin Islands. I tell students that will be reading a factual story of two islands off the coast of Alaska and the environmental changes that occurred there as studied by a group of scientists. Then tell them as they read they are to use up highlighter or pencil and identified the terms (noun or noun phrases only) that change over the course of this story.  Ask if there are any questions and then give them time to read and highlight.


30 minutes

As the students are reading circulate the room to be sure that they understand what they are to do and monitor the pace at which students are getting through the article. If you notice that some students are not identifying variables you may have a discussion with them about a particular section of the reading that they skipped over or missed some key parts. It's not essential that they identify every element that change the story at this time as the entire class will have a discussion on this shortly.

Once the class is finished with the reading instruct them to turn to their table group and discuss the elements that they identified in the story that changed. Ask one student to be described and make a master list of all of those terms. Explain to them it's okay if they can't reach consensus on all the items so long as everyone has a voice at the table and contributes to the group list. Once you see all the table groups are nearly finished bring the class back together. 

Asked the class to think about the central problem to the story and ask them to summarize the central problem in 20 words or less. Call on students once they are ready and have the class vote, thumbs-up or thumbs down, if they agree with the problem statement. Modify it as needed so that you have a agreed-upon statement for the class then write the problem statement on the board.

Next, tell students that you will make a master list of the variables that change throughout the story. To facilitate this use a sheet of chart paper or the display board to record students responses. I like to begin with one table group and record their entire list on the board. Then I moved to the next table group and ask if there's anything on their list missing from the class list and add those terms. Continue this way for all groups in the class then review the list and make sure that everyone agrees on the items that are there. You should end up with anywhere from 7 to 12 elements at this point.

Hand out the BOTG worksheet.pdf worksheet. Instruct students to record the variables that changed from the class list under Elements Changing  then create a BOTG for each element on the plot to the right. I tell them to work on this as a table group.

They are now ready to begin creating the connection circle. Give them the Template-CC-BOTG.pdf. Ask them to write the elements around the circle from their list adding the BOTG to each element. It's a good idea to model this process on the display board while they do it at their table. Next leave them in a discussion to identify elements that cause other elements to increase or decrease for instance if the number of for trade or sweat up then the number of sea otters went down. Students would then draw an arrow from for traders to see otters and place a minus sign or O to show that this relationship is in the opposite direction. In other words as one element went up the other went down. Continue making these connections with all of the elements in the story keeping in mind that the connections must be direct and either increase or decrease.

Once this is completed ask students to look for feedback loops and tell their story. These would be smaller connections within the circle. In the image below these are highlighted. Notice the (B) and (R) symbols within these loops. These stand for Balancing and Reinforcing loops. 



15 minutes

Once students have had a chance to study their connection circles and identify the feedback loops given the chance to discuss what they learned during this exercise. Here are some suggested questions you could use to facilitate discussion.


  • How did the connection circle help you sort out the various things happening in the story?
  • What was the effect the sea otters had on this year to population and the balance of the two ecosystems?
  • What was the effect of the first traders on the ecosystems of the two islands?
  • What is the author mean when she called the sea otters a keystone species?

Students will have a chance to practice these skills in the next lesson.