FOUR EXPERIMENTS WERE CONDUCTED TO EVALUATE PROGRAMED INSTRUCTIONAL MATERIALS DESIGNED FOR TEACHING CIRCUIT THEORY AND FORTRAN AT THE COLLEGE LEVEL. IN THE FIRST EXPERIMENT, APPLICATIONS OF PRINCIPLES CONCERNED WITH PROACTIVE AND RETROACTIVE INHIBITION (NEGATIVE TRANSFER OF LEARNING) WERE STUDIED. THE REMAINING THREE EXPERIMENTS WERE DESIGNED TO STUDY EFFECTS OF (1) IDEATIONAL SCAFFOLDING (SUMMARIZATION) PRECEDING PROGRAMED SEGMENTS OF A BRANCHING TEXT, (2) LEARNER-DETERMINED ALTERNATIVES IN A BRANCHING PROGRAMED TEXT, AND (3) EFFICACY OF WRITTEN AND READING RESPONSES TO A LINEAR PROGRAMED TEXT. MATERIALS TESTED IN THE FIRST EXPERIMENT GENERATED RETROACTIVE AND PROACTIVE INTERFERENCE. SUMMARIZATION PRIOR TO A PROGRAMED INSTRUCTION SEGMENT HAD NO BENEFICIAL EFFECT. THE THIRD STUDY INDICATED THE NECESSITY OF OBTAINING HIGHLY DETAILED FEEDBACK FROM LARGE GROUPS FOR DEVELOPING BRANCHING TEXTS. WRITING OF RESPONSES DID NOT INCREASE IMMEDIATE OR DELAYED RECALL OF PROGRAMED FORTRAN. IMPLICATIONS OF THE EXPERIMENTAL FINDINGS WERE DISCUSSED FOR SUBSEQUENT RESEARCH AND DEVELOPMENT OF PROGRAMED INSTRUCTION MATERIALS. (WN)