The Transregional Collaborative Research Center (TRR 318) „Constructing Explainability“ investigates how explanations of algorithmic decisions can be made more efficient by constructing them jointly by the explainer and the explainee. The project A01 “Adaptive explanation generation” investigates the cognitive and interactive mechanisms of adaptive explanations. The goal of our work is to develop a dynamic, computational model of the representations and decision processes with which “pragmatic explainers” adapt their explanations to their addressees. To that end, cognitively motivated methods for model-based machine learning are developed, applied, and evaluated.