We present results of a two-semester study to determine whether the inclusion of basic animation techniques in PowerPoint presentations provides an additional learning aid, inhibits learning, or has no effect on student learning for students in an introductory astronomy course. We found that (1) students perceive that animated slides are substantially more effective; (2) student understanding as measured via in-class exams is largely unaffected by the use of animated slides, but that end-of-semester diagnostic surveys may indicate that animated presentations aid in long-term retention of the material; and (3) the animation of illustrations may provide a greater impact on learning than simply the animation of text. (Contains 5 tables and 3 figures.)