This work focuses on the use of animations for learning complex and dynamic mental models. Animations can provide more information than pictures but can also interfere with learning since learners have to actually process this information, and do it in real time. Through five experiments, using four different animations, we explored the way learners used the available information to understand the depicted phenomenon. We studied the effect of features allowing learners to consult previous states of the animation (snapshots, control and interactivity over the content). We also used a collaborative learning setting in order to improve the processing of the information by the learners. Through these experiments, we adapted and developed methods to describe the learning processes beyond what we could observe with our experimental conditions. The results allowed us to enrich our comprehension of the specific processes involved when learning from animations. In particular, our fifth experiment showed qualitative differences in the visual representation constructed from static pictures or from animations. Our discussion on these results led us to describe a framework of cognitive processes implicated when learning from multimedia materials.