This is the third revision of a primer on all aspects of educational technology. It offers an authoritative overview of approaches and interpretations as well as detailed descriptions of specific techniques. Topics covered include: the nature of educational technology; basic educational strategies such as the teacher/institution-centered approach and the student-centered approach; educational objectives and competence descriptors; group, individual and mass-instruction techniques; assessment and evaluation; resource centers, including their role, planning, organization, and operation; computers in education and training; and a glimpse into future trends. The book also contains three reference sections: a glossary defining almost a thousand terms, a comprehensive bibliography, and a keyword index. (DGM)