Publication Date



Social System Design Lab, Washington University in St. Louis


There are several features of complex systems that make creating change in K-12 education difficult, including: delays between the intervention and outcome, unexpected or confusing responses to interventions, and differences in how individuals and groups experience the same systems. The concept of “accumulation” provides important insight into how misperceptions, delays, and counter-intuitive system responses occur in education change efforts. Stock [BE1] and Flow Diagrams are visual tools to identify and visually describe key accumulations in the systems and facilitate conversations to understand systems better.

The purpose of this brief is to describe how the concept of accumulation can help us understand system behavior and to introduce how stock and flow diagrams can be used to help us model problems and find solutions in K-12 education.

Series Number

Methods Brief Series 1.06: Systems Thinking Foundations

Document Type

Research Brief