A brief intervention to improve reasoning about accumulation

Prior research suggests that people often misunderstand visualizations of inflow (e.g., deposits in a banking context) and accumulation (e.g., cumulative savings) in dynamic systems. The present study aimed to examine participants' understanding of accumulation functions and to develop and test the effectiveness of video-based interventions for improving understanding of accumulation. In Experiment 1, we tested the effectiveness of an intervention seated in the context of understanding COVID-19 data. In Experiment 2, we addressed several limitations of Experiment 1 and developed an improved, more general intervention to teach about accumulation in contexts outside of epidemiological data. The two randomized control experiments demonstrated that people fail to understand even simple systems with a single inflow that accumulates over time, with 44%-60% of participants earning a 0% on our pretest measure. However, we also demonstrated that video-based interventions illustrating the relationship between multiple representations of the same underlying data are an effective way to improve the understanding of the relationship between inflow and accumulation, with Experiment 1 suggesting that the effects of our intervention lasted up to 6-7 weeks after testing. (PsycInfo Database Record (c) 2025 APA, all rights reserved).