THIS FINAL REPORT DESCRIBES TWO RESEARCH EXPERIMENTS CARRIED OUT IN TOKYO IN 1965 AND 1966. STUDY A, A COMPARATIVE STUDY OF THE ACQUISITION OF A FOREIGN LANGUAGE AT TWO DIFFERENT AGE LEVELS (3RD AND 4TH GRADES), WAS BASED ON A COURSE OF THREE 15-MINUTE SESSIONS A WEEK, USING TEN-MINUTE TAPES. SOME RESULTS NOTED WERE--(1) NO DIFFERENCE BETWEEN GRADES IN THE FIRST AURAL TEST, A SIGNIFICANT DIFFERENCE IN THE SECOND TEST FIVE MONTHS LATER, (2) A SIGNIFICANT PREDOMINANCE OF 4TH GRADERS OVER 3RD IN ORAL PRODUCTION, (3) NO SIGNIFICANT DIFFERENCE IN "MIMICRY," AND (4) NO CORRELATION BETWEEN PUPILS' SCORES AND IQ'S IN THE PERCEPTION TEST. STUDY B WAS A COMPARATIVE STUDY OF A 5TH-GRADE "TAPE-LESSON" CLASS WITH A 5TH-GRADE "LIVE-VOICE" CLASS. LESSONS WERE SOMEWHAT MODIFIED AND USED 15-MINUTE TAPES. SOME RESULTS OF THIS STUDY WERE--(1) NO SIGNIFICANT DIFFERENCE BETWEEN THE EXPERIMENTAL (TAPED LESSONS) GROUP AND THE CONTROL GROUP IN PERCEPTION TESTS, (2) SIGNIFICANT DIFFERENCE (AT A LEVEL OF ONE PERCENT IN FAVOR OF THE CONTROL GROUP) IN THE SECOND AND THIRD AURAL COMPREHENSION TESTS, (3) A SIGNIFICANT PREDOMINANCE OF THE CONTROL GROUP IN THE SECOND (LAST) PRODUCTION TEST, AND (4) A SUPERIORITY OF THE EXPERIMENTAL GROUP IN INDIVIDUAL SOUNDS AND FLUENCY IN THE "MIMICRY" TESTS. THIS REPORT IS PUBLISHED BY THE JAPANESE NATIONAL COMMISSION FOR UNESCO AND THE MODERN LANGUAGE INSTITUTE OF THE TOKYO UNIVERSITY OF EDUCATION. (AMM)