The creation of the Common European Framework of Reference for Languages (CEFR) has given rise to interest and debate among policy makers, testers, teachers and researchers alike in the reliability and feasibility of the assessment of second language (L2) proficiency. This volume brings together concrete ideas on identifying and measuring L2 proficiency from different branches of SLA research (psycholinguistic, sociolinguistic, corpus-based, applied linguistics) to contribute to a deeper understanding of what it means to be proficient in an L2. The chapters introduce a wide range of tools...