Dynamic visualisations capture aspects of scientific phenomena that are difficult to communicate in static materials and benefit from well-designed scaffolds to succeed in classrooms. We review research to clarify the impacts of dynamic visualisations and to identify instructional scaffolds that mediate their success. We use meta-analysis to synthesise 47 independent comparisons between dynamic and static materials and 76 comparisons that test the effect of specific instructional scaffolds. These studies show that dynamic visualisations are better than static visuals at promoting conceptual inferences about science, consistent with the success of inquiry instruction in science. To realise this potential of dynamic visualisations, instruction needs to help students use the dynamic visualisation to make sense of their own ideas. Scaffolds that are most successful include prompts for reflection, prompts to distinguish among parts of the visualisation, visual cues that identify salient features, multiple visualisations presented sequentially, and interactive features that govern the pacing of activities. We extract guidelines from this research to help researchers plan future studies of visualisations, designers create and refine instructional materials using visualisations, and practitioners customise instruction that features visualisations.