The objectives of the study were: (1)  To study the concept of Educational Technology and its application in the teaching - learning process of the secondary schools of Greater Bombay. (2) To study the attitude of the secondary school teachers / supervisors / principals towards the application of Educational Technology in the teaching-learning process of the secondary school of Greater Bombay. (3) To study the text of the application of Educational Technology in the classroom teaching- learning situations of secondary schools of Greater Bombay. (4) To study the extent of effectiveness of the application of Educational Technology in terms of pupils academic achievement in the secondary schools of Greater Bombay

The hypotheses of the study were: (1) There exists no significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Science (Biology) through classroom teaching with Educational Technology and without Educational Technology. (2) There exists no significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Mathematics through classroom teaching with Educational Technology and without Educational Technology. (3) There exists no significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Language Hindi through classroom teaching with Educational Technology and without Educational Technology. (4) There exists no significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Social Study through classroom teaching with Educational Technology and without Educational Technology. (5) There exists no significant difference in the attitudes of the Greater Bombay secondary school teachers in English medium, Marathi medium, Hindi medium and Gujarati medium towards the application of Educational Technology  in their classroom teaching. (6) There is no significant difference in the use of Educational Technology in classroom teaching among the secondary school teachers of  English medium, Marathi medium, Hindi medium and Gujarati medium of Greater Bombay. (7) There is no significant difference in the effectiveness of Educational Technology through classroom teaching among English medium, Marathi medium, Hindi medium and Gujarati medium secondary schools of greater Bombay.

Sample consisted of 130 teachers and  20 principals of secondary schools of greater Bombay, and 560 secondary school pupils ranging from standard V to IX.

Achievement test in Science, Mathematics, Language (Hindi), and Social Study and self made questionnaire, interview schedule and observation schedule were used as tools. 

For the present experimental study, equivalent group post-test experimental design was followed. 

 Data were analyzed by using t-test.

The findings showed that: (1) There exists a significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Science (Biology) through classroom teaching with Educational Technology and without Educational Technology. (2) There exists a significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Mathematics through classroom teaching with Educational Technology and without Educational Technology. (3) There exists a significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Language Hindi through classroom teaching with Educational Technology and without Educational Technology. (4) There exists a significant difference in the academic performance of the secondary pupils of Greater Bombay in the subject Social Study through classroom teaching with Educational Technology and without Educational Technology. (5) There exists a significant difference in the attitudes of the Greater Bombay secondary school teachers in English medium, Marathi medium, Hindi medium and Gujarati medium towards the application of Educational Technology in their classroom teaching. (6) There is a significant difference in the use of Educational Technology in classroom teaching among the secondary school teachers of  English medium, Marathi medium, Hindi medium and Gujarati medium of Greater Bombay. (7) There is a significant difference in the effectiveness of Educational Technology through classroom teaching among English medium, Marathi medium, Hindi medium and Gujarati medium secondary schools of greater Bombay.