Validity of Peer Assessment of Speaking Performance : A Case of Japanese High School Students

Abstract

The main purpose of this study is to examine the validity of peer assessment (PA) in high school education, compared to that of teacher assessment (TA), so as to make assessment of speaking performance more practical. The validity of PA is also examined in terms of students' English proficiency levels and in relation to varied PA group size. In order to reach these goals, research was conducted with approximately 80 Japanese high school students, and the data was statistically analyzed. Based on the current approach to validity (Chapelle, 1999), the validity of PA is examined from three perspectives: concurrent validity, face validity, and reliability. The results of this research strongly suggest that the validity of using PA to evaluate student's speaking performance is similar to that of TA. Considering the students' English proficiency, a difference in validity was observed, but it is considered to be quite small. Furthermore, in relation to PA group size, there is a tendency that PA grows more valid as group size increases. Based on these findings, some practical implications are suggested.