AbstractTwo experiments were carried out to investigate how remedial instruction may be given to students who have difficulties in understanding the three‐dimensional spatial relationships portrayed in diagrams of three‐dimensional structures. Both experiments are based on a model which describes this kind of understanding in terms of the ability to respond correctly to each of four depth cues in the diagrams, and the ability to combine these depth cues correctly.Experiment I shows that remedial instruction in responding to only one of the cues, brings about a significant increase in overall understanding. Experiment II shows that overall understanding is significantly enhanced by giving remedial instruction on two cues as opposed to one cue, and that teaching students to combine the cues improves on the effects of teaching students to respond correctly to just one depth cue. It is concluded that all the results are consistent with predictions made from the underlying theoretical mo