Abstract for: In Search of Explanations for Stock-Flow Performance

Research repeatedly shows that people have difficulties performing stock-flow tasks. People do not understand the principle of accumulation and seem to use wrong heuristics while doing these tasks (Cronin et al., 200; Sterman, 2010). In this study we explore two possible sources of explanations for stock-flow performance: reasoning patterns as verbalized by participants while performing stock-flow tasks and individual decision making characteristics. This paper reports an experiment in which participants are randomly assigned to a task, department store or bank, and a condition, verbal (using a think aloud protocol) or written. The different tasks do not reveal differences in performance. The combined task results are comparable with previous research. An analysis of think aloud protocols reveals a set of reasoning patterns giving rise to particular stock-flow performance. In line with the literature many stock-flow failures in this study also seem to be a result of the correlation heuristic, more specifically as a stock-net flow correlation. However, we also find additional incorrect reasoning types and other sources of problems. As a second source of explanations we relate individual decision making characteristics to stock-flow performance. We find that need for cognition and need for deliberation correlate positively with participants’ stock-flow performance.