The technology, symbol systems, and processing capabilities of a medium interact to provide unique opportunities for information access. This exploratory study examines the way that learners process videotaped materials on a familiar or unfamiliar topic as informed by text-based research. A variation of the think-aloud method of assessing cognitive processes was used to gain insight into the role of prior knowledge in learners' thoughts while viewing a videotape on the topic of instructional design. The nine participants in this study were enrolled in a graduate class in video production at a large midwestern university; participants were classified as either experienced in instructional design or unfamiliar with the topic based on prior exposure. The data from the think-aloud protocols suggest that all participants were attempting to relate the new information presented via videotape to topics with which they were familiar; in addition, all of those unfamiliar with the topic and half of those with experience in instructional design were frequently evaluating the production of the videotape while viewing the program. Analysis of the teach-back protocols provided additional information on the cognitive processing of the videotaped information. Participants with experience in instructional design included a greater percentage of inferences which linked the content of the videotape with other related ideas; participants unfamiliar with the topic included a greater percentage of comments that elaborated on the content of the tape. The results of this investigation provide evidence that the think-aloud and teach-back methods can be used successfully to gain insight into the cognitive processing of videotaped materials. (Contains 8 references.) (AEF)