Graphs of real-time experiments are useful tools in science education; their intrinsic features allow innovative didactic approaches. The use of such images is spreading and is likely to become common classroom practice. This paper describes a study in which secondary school students were called upon to read and interpret documents containing images of real-time kinematics graphs specially designed to address common learning problems and to minimize iconic difficulties. Both novice students and those with a little experience of real-time experiments were involved. The overall didactic intentions of the presented documents were fulfilled. Some reading difficulties related to specific features were detected and are discussed. Suggestions are made regarding the acquisition of some specific capabilities that are needed to avoid misinterpreting these images and are of transversal value across several contexts. Finally, some implications for teacher training and class activities are discussed.