AN EFFORT WAS MADE TO IDENTIFY SPECIFIC KNOWLEDGES AND CLUSTERS OF KNOWLEDGES MOST WIDELY USEFUL IN MAJOR TYPES OF WORK COMMONLY DONE BY ELECTRONIC TECHNICIANS. PRINCIPAL TASKS OF TECHNICIANS WERE CLASSIFIED AS (1) DIAGNOSING TROUBLE IN SYSTEMS, (2) ADJUSTING AND OPERATING, (3) SERVICING, (4) ASSEMBLING, (5) INSTALLING, (6) DESIGNING AND COMPUTING, (7) APPLICATION, DISTRIBUTION, AND SALES IN ELECTRONICS, AND (8) QUALITY CONTROL AND TESTING. A QUESTIONNAIRE LISTING 643 KNOWLEDGES EXTRACTED FROM TEXTBOOKS, CURRICULUM GUIDES, AND COURSES OF STUDY WAS ADMINISTERED TO A SAMPLE OF WORKERS IN 64 ESTABLISHMENTS BROADLY REPRESENTATIVE OF THE NATIONAL PATTERN OF ELECTRONIC TECHNICIANS' WORK. THESE WORKERS DEEMED 84 OF THE 643 KNOWLEDGES ESSENTIAL FOR PERFORMANCE OF SIX OF THE EIGHT PRINCIPAL TASKS, AND 154 ESSENTIAL FOR PERFORMANCE OF THREE TO FIVE PRINCIPAL TASKS. THESE DATA WERE PROVIDED BY 154 USABLE QUESTIONNAIRES. THIS VOLUME REPRESENTS PART 4 OF THE 13-PART FINAL REPORT ON THE VOCATIONAL-TECHNICAL EDUCATION RESEARCH AND DEVELOPMENT PROJECT OF WASHINGTON STATE UNIVERSITY. RELATED REPORTS ARE ED 010 652 THROUGH ED 010 664. (JH)