This study investigated the effectiveness of three different levels of enhancement strategies utilized to facilitate students' learning from static and animated visualization when taking the time-on-task into consideration. Participants were randomly assigned to six treatment groups, and then took four criterion measures. The time-on-task was measured and used as a covariate in the analysis. The results suggest that animation is more effective than static visuals for improving learning across all levels of learning. Questions plus feedback embedded into the visualized material are most effective in enhancing higher-level but not lower-level learning objectives. Furthermore, time-on-task may be interpreted differently. On the one hand, students should be allowed as much time as needed to learn material when it is enriched, such as in the animated lesson. On the other hand, requiring students in a static-only treatment to review the visuals may produce the same learning effect as the use of animated visuals.