Describes the use of videodisk technology to deliver instruction to preservice and in-service teachers for mastery of earth science concepts, and discusses its use as a research tool to improve teacher preparation in science education instructional methods for elementary schools. A science teaching model that underlies the research program is…

Awareness of the need for more effective instruction for heterogeneous groups of students has resulted in the development of the "mastery learning" model through which students are provided with the additional time necessary to achieve mastery of the content to be learned. The mastery learning model does not, however, provide a…