Simulation-based learning environments are used extensively to support learning in complex business systems. Nevertheless, studies show that subjects have great difficulty in understanding and managing dynamic systems, mainly due to cognitive processing difficulties. Previous research has addressed some aspects of model transparency and instructional strategy and produced inconclusive results about their impact on learning effectiveness. This study explores the learning and performance effects of using transparent simulations (that is, showing users the internal structure of models) and applying structural and behavioural debriefings focussed respectively on the critical variables and relations and on the relation between model structure, patterns of actions, and system behaviour. We present a set of hypotheses about the influence of the model transparency and debriefing conditions on participants' performance and comprehension of the system dynamics. In a simulation experiment,