The purpose of this study is to analyze the readability of reading passages used in 5th and 6th grade elementary school English textbooks under the 2015 Revised National Curriculum. For this purpose, all the reading passages of each textbook were calculated with ATOS (Advantage-TASA Open Standard) formula as a readability index. The results of this study indicate that, firstly, the average readability score of 6th grade English textbooks is higher than that of 5th grade ones. Secondly, the readability of 6th grade English textbooks is about six months ahead of that of 5th grade ones. Thirdly, the readability scores are similar in all reading passages for 5th grade, while the readability scores of 6th grade differ from textbooks to textbooks. According to the textbook writers, the readability score of 6th grade textbooks is higher than that of 5th grade ones in four out of five textbooks. Lastly, In terms of the units in each textbook, the readability scores fluctuate and do not increase sequentially as expected.

I. 서론
II. 이론적 배경 및 선행연구
    1. 이독성(readibility)의 정의 및 활용
    2. 이독성 지수 문헌연구 사례
III. 연구 방법
    1. 분석 대상
    2. 분석 방법
Ⅳ. 연구 결과 및 논의
    1. 코퍼스 기초 분석 결과
    2. ATOS를 활용한 이독성 지수 결과
Ⅴ. 결론 및 제언
참고문헌

• 황은경(명지대학교) | Hwang Eunkyung
• 박광현(명지대학교) | Park Kwanghyun 교신저자