The objective of the study were: (1) To establish the relative effectiveness among different instructional strategies viz. conventional lecture method, CAI as individualized instructional strategy and CAI as a support system to teachers’ classroom instruction in teaching physics at higher secondary level. (2) To find out whether there is any significant difference among different instructional strategies viz. conventional lecture method, CAI as individualized instructional strategy and CAI as a support system to teachers’ classroom instruction in terms of their effectiveness in modifying the cognition among the higher secondary students in physics at different levels, viz., knowledge, understanding and application. (3) To find out whether there is any significant difference among different instructional strategies viz. conventional lecture method, CAI as individualized instructional strategy and CAI as a support system to teacher’s classroom instruction in their effectiveness in terms of their power as reveled by the learner’s performance in the retention test. (4) To develop syllabus based computer software packages in teaching physics at higher secondary level. (5) To develop a computer managed teaching software package for assessing the academic achievement of pupils in physics through computer before and after experimentation. (6) To evaluate the developed computer software packages from technical and pedagogical points of view by experts, educationists and practicing teachers. (7) To develop criterion tests in the content areas taught through different instructional strategies in the present study. (8) To find out whether there is a significant relationship between pupils academic achievement in physics and their different psychological variables.

Tools used for data collection were: Six syllabus based computer software packages in the content areas, viz., LAZER, atom models, spectral series, nuclear fission, nuclear fusion, nuclear reactor and diode prescribed for 12th standard physics developed by investigator using C-language; A computer managed testing software developed by investigator using dBase III plus, six objectives based criterion tests in the selected content areas developed by investigator to access the entry and terminal behaviors of the pupils; Culture fair intelligence test scale 3; Scientific Attitude Test (SAT); Achievement Motivation and Anxiety Inventory; Probabilistic Orientation Questionnaire (POQ); Internal – External (I -E) locus of control inventory. 

Pretest – Post test equated group design were employed to conduct experimental study. 

The data were analyzed with the help of t-test and correlation techniques.

The findings of the study were: (1) The three instructional strategies are effective in enhancing the instructional objectives in physics at all levels of cognition at standard XII. (2) The CAI as support system to teachers’ classroom instruction is more effective when compared to conventional lecture method and CAI as individualized instruction in achieving the instructional objectives in physics at all levels at standard XII. (3) Conventional lecture method and CAI as individualized instruction are equally effective in achieving the instructional objectives in physics at all levels of cognition at standard XII. (4) CAI as support system is more effective when compared to CAI as individualized instruction and conventional lecture method in improving at knowledge, understanding and application levels of the pupils when the difficulty level of the content is higher. (5) Conventional lecture method is more effective when compared with CAI as individualized instruction in modifying the cognition at all levels except at knowledge level in the content where the difficulty level of the content is low. At knowledge level CAI is more effective when compared to lecture method. (6) CAI as support system to teachers’ classroom instruction is more effective when compared to CAI as individualized instruction and conventional method of teaching in enhancing retention at total, knowledge, understanding and application levels in the content areas taught through three means in physics at standard XII. (7) Psychological variables of the pupils have no influence in determining the effectiveness of the instructional strategies viz. CAI as individualized instruction and CAI as support system to teachers’ classroom instruction. (8) CAI as individualized instruction and CAI as support system to teachers’ classroom instruction system have no influence on Internal – External locus of control, probabilistic orientation, intelligence, achievement motivation and scientific attitude of the pupils’.