Abstract
The role of response effects (tendencies to respond to factors other than item content) in the self-assessment of second language ability was investigated through a split-ballot procedure using positively- and negatively-worded ques tions and graded (i.e. level-specific questions). Results indicate that both an acquiescence effect (a tendency to respond positively regardless of item con tent) and overestimation were present. Although both effects were present at all levels of subjects, they were most evident for less experienced learners. Discussion focuses on explanation of these effects and implications for both test construction and pedagogy.