Making Thinking Visible: Stocks and Flows

 

Stocks and Flows are the basic building blocks of system dynamics maps and models. Using stocks and flows allows people to make visible both concrete and abstract concepts. A stock is an accumulation (trees in the forest, happiness of a child, water in the bathtub). A flow changes a stock over time. An inflow adds to the stock while an outflow subtracts with the stock. Like Behavior over Time Graphs, stocks and flows depict how a system changes over time, but they also represent interdependencies in a system. The following articles and curriculum provide a gateway to using this powerful tool in the classroom.

 

Making Friends from The Shape of Change
By Rob Quaden and Alan Ticotsky with Deb Lyneis
Students explore what happens to the number of friends over time, given different scenarios for gaining new friends. Students can also explore what might happen if they lose friends.

Getting Started: Five lesson plans to help teachers introduce System Dynamics to their students
by Cathy Curry
Five lesson plans which support the introduction of System Dynamics in the classroom. These five lesson plans are complete with class and homework assignments and will take teachers and students through the steps necessary in learning any new method.

Everyday Stocks and Flows: Problem Sets for Middle Grades
by Alan Ticotsky
Stock/flow diagrams and computer modeling are wonderful tools to help us understand and solve complex problems and systems. But they should not be reserved only for those complex scenarios. Teaching young students to draw stock/flow diagrams to understand simpler problems helps them to begin thinking systemically.

Use Stocks and Flows to Build a Personal Finance Model
by Jeff Potash
In this video Jeff introduces how to build a model using Stocks and Flows. This introductory lesson is a key building block in the Dollars and Sense lessons.