Abstract for: Absent or distant? On the use of indirect causal links and chains of causal links to compare mental models of dynamic systems

The subject of articulating and comparing mental models of dynamic systems has been present in system dynamics since many years now. Methods have been borrowed from other disciplines and been adapted to the specific needs of system dynamics. They all focus on variables and causal links, and most recent ones include feedback loops. However, this focus has problems to deal with differences stemming from different degrees of aggregation. Here it is proposed to insert chains of causal links as level of analysis. A simple example is used to show how this can be done; first a reference model is defined with a standard length for each causal chain; then a distance matrix representation of causal diagrams is used and two new indicators relative length difference and relative content difference are shown to provide useful information for interpreting different levels of aggregation in the causal connection between flows and stocks.