Abstract: In 1983, Richard Clark, reviewing the literature on instructional technology, stated that instructional media have no effect on learning. He claimed that “media are mere vehicles that deliver instruction but do notinfluence student achievement any more than the truck that delivers our groceries causes changes in nutrition,” and his statement has attracted a flood of response from educational researchers for over thirty years. In response to criticism, Clark proposed a“ replacability test,” a challenge that there is no medium that can’t be replaced with another instructional method that will produce the same result. Due to its length and inconclusiveness, some researchers, such as Richard Mayer (2010), have suggested that the media debate is unproductive, and researchers should instead direct their attention to finding the most effective instructional techniques. This paper proposes, asdoes Sharon Shrock (1984), that the media debate is well worth revisiting because it involves issues of central importance to instructional research. The debate is also worth another look because the development of new mediahas shifted the context of the discussion.