Previous studies have shown that learners' individual differences have dissimilar impacts on their improvement in accuracy in the target language (DeKeyser, 1993; Mackey, Adams, Stafford, & Winke, 2010; Mackey & Sachs, 2012; Sheen, 2007). The present study focused on a learner variable (i.e. extraversion) and examined whether more extraverted learners engaged in a greater number of focus-on-form episodes in class and whether this involvement could further lead to immediate improvement in accuracy of a target language. A total of 28 English-as-a-second-language students in an advanced and an upper-intermediate class participated in the study. They filled out a personality questionnaire, and each class was observed for four class sessions for a total of eight sessions. Out of a total of 16 hours of observation, only 12 hours from three obseravtion sessions from each of the classes were analyzed due to the focus of the present study. Based on the three class observation sessions from both classes, individualized post-tests were created, and the participants completed the tests six to ten days after the final classroom observation. The data were then analyzed using statistical methods including Pearson's product-moment correlation coefficient and Spearman's rank-order correlation coefficient depending on the normality of the data. The results revealed that in the advanced class, more extraverted learners were more likely to engage in interaction where learner attention was directed to linguistic elements. On the other hand, more introverted learners were found to produce more successful uptake in the upper-intermediate class. The findings partially support the role of extraversion in learners' participation in focus-on-form episodes as well as immediate L2 development. However, the findings did not suggest that the learners' self-reports and the teacher's perception of his learners' levels of extraversion were significantly correlated. / Graduate / 0282