Today, although much debate surrounds the effectiveness of including graphics in Web-based distance education courses, most course authors agree that such courses should productively engage students so that quality of learning actually occurs. But what is productive engagement in a world of electronic communication and text? This paper offers a possible answer to this question by providing evidence that the use of graphics can enhance online teaching. The evidence includes a description of: the use of four different visualization types and techniques as instructional tools; the positive perceptions of 22 undergraduate students toward the use of these types and techniques; and the beneficial impact of their use on learning outcomes in an online undergraduate science course. (Contains 12 references.) (Author)