Understanding the building blocks of dynamic systems

We report three empirical studies intended to clarify why individuals misperceive the relationships between stocks and flows. We tested whether familiarity with the problem type, motivation to solve the problem, or the graphical presentation of the problem affected participants' understanding of stock and flow relationships. We conclude that the misperceptions of stocks and flows are a pervasive and important problem in human reasoning. Neither the domain familiarity nor increased motivation helped individuals improve their perception of stock and flow relationships; but it seems that the graphical representation directs attention to flows and not stocks, setting the stage for subsequent mistakes. Individuals attend to the most salient points of a graph rather than comprehending the overall accumulation over time. Future research needs to investigate several aspects of the problem representations, such as the use of physical or textual rather than graphical representations. Copyright (c) 2007 John Wiley & Sons, Ltd.