This study investigated how enriching visualizations with arrows indicating the motion of objects may help in conveying dynamic information: Multiple static-simultaneous visualizations with motion-indicating arrows were compared with either multiple visualizations without arrows or a single visualization with arrows. Seventy-one students were randomly assigned to the three conditions. Learning outcomes were measured by dynamic and static pictorial test items requiring learners to classify objects according to their locomotion pattern. Even though learners' performance in the static test indicated some use of static cues, they showed better performance once dynamic information was available suggesting that it is applied to accomplish the task. Unexpectedly, the combined condition performed worse than both other conditions in the dynamic test. Accordingly, multiple visualizations without arrows and single visualizations with motion indicators appear to facilitate mental animation differently either by supporting comparisons among multiple pictures or by making dynamic information explicit. However, combining both instructional methods may result in interference thereby hindering learning. (Contains 4 tables and 5 figures.)