There is no written evidence which can tell us exactly who has coined the phrase educational technology. Different educationists, scientists and philosophers at different time intervals have put forwarded different definitions of Educational Technology. Educational technology is a multifaceted and integrated process involving people, procedure, ideas, devices, and organization, where technology from different fields of science is borrowed as per the need and requirement of education for implementing, evaluating, and managing solutions to those problems involved in all aspects of human learning.
Educational technology, broadly speaking, has passed through five stages.
The first stage of educational technology is coupled with the use of aids like charts, maps, symbols, models, specimens and concrete materials. The term educational technology was used as synonyms to audio-visual aids.
The second stage of educational technology is associated with the ‘electronic revolution’ with the introduction and establishment of sophisticated hardware and software. Use of various audio-visual aids like projector, magic lanterns, tape-recorder, radio and television brought a revolutionary change in the educational scenario. Accordingly, educational technology concept was taken in terms of these sophisticated instruments and equipments for effective presentation of instructional materials.
The third stage of educational technology is linked with the development of mass media which in turn led to ‘communication revolution’ for instructional purposes. Computer-assisted Instruction (CAI) used for education since 1950s also became popular during this era.
The fourth stage of educational technology is discernible by the individualized process of instruction. The invention of programmed learning and programmed instruction provided a new dimension to educational technology. A system of self-learning based on self-instructional materials and teaching machines emerged.
The latest concept of educational technology is influenced by the concept of system engineering or system approach which focuses on language laboratories, teaching machines, programmed instruction, multimedia technologies and the use of the computer in instruction. According to it, educational technology is a systematic way of designing, carrying out and evaluating the total process of teaching and learning in terms of specific objectives based on research.
Educational technology during the Stone Age, the Bronze Age, and the Iron Age
Educational technology, despite the uncertainty of the origin of the term, can be traced back to the time of the three-age system periodization of human prehistory; namely the Stone Age, the Bronze Age, and the Iron Age.