We offered introductory psychology on the World-Wide Web (WWW) and evaluated the on-line format relative to the traditional lecture-test format, using a pretest-posttest nonequivalent control group design. Multiple sections of the introductory course were offered each semester; on-line and lecture sections were taught by the same instructor, the same textbook was used, and the same in-class examinations were taken. For on-line sections, mastery quizzes, interactive individual exercises, and weekly laboratory meetings replaced lectures. Increased content knowledge was greater for the students in the Websections, as was in-class examination performance. Use of the WWW and computers for academic purposes increased more in the on-line sections, and the on-line students showed a greater decrease in computer anxiety. The students in the on-line sections expressed appreciation for course components and the convenience of the course, but the lecture sections received higher ratings on course evaluations than did the on-line sections. Learning and course satisfaction were dissociated in the two course formats.Information technology appears to hold great promise for improving learning and increasing access to higher education via distance learning opportunities (see, e.g., Bork, 1997; Dede, 1996). However, despite a long history of computer-assisted instruction and distance education, there is little well-controlled empirical research regarding the effects of such technology. In two recent reviews, one on distance learning (Merisotis & Phipps, 1999) and one on hypermedia (Dillon & Gabbard, 1998), few papers remained after reports ofinterface design, opinion pieces, and reports of research lacking control groups were excluded. Thus, even while the potential of information technology continues to grow, our knowledge about its effects on learning remains scant. Such knowledge, gained from sound designs, is needed in order to deploy instructional technology most effectively.We developed an introductory psychology course, using the World-Wide Web (WWW) as an alternative to a lecture format.' This alternative format addressed several problems associated with large introductory courses (see,