Many researchers confirm that confidence factor plays a significant role in oral English training. However, lack of reliable evaluation methods renders teachers impotent in measuring individual confidence variation. They can do little more than form a rough impression on the basis of students' test scores and their personality traits, which proves deceptive and misleading. This paper introduces the notion of confidence index as an evaluation criterion, and empirical investigation reveals the wide variation in individual confidence index. Finally this paper explores the correlation between confidence factor and proficiency.
