English teachers' diagnostic skills in judging their students' competencies on the basis of the Common European Framework of Reference

The present study addresses diagnostic competence of English language teachers at the end of lower secondary education. The 56 teachers assigned each of their respective students (N = 1 363) to a proficiency level of foreign language use according to the Common European Framework of Reference for Languages (CEFR). The teachers' judgements were compared to CEFR proficiency level assignments estimated using data from a reading comprehension assessment of English as a foreign language. The consistency of proficiency level allocations was evaluated using level, differentiation, and ranking components. Beyond providing a description of diagnostic competence, the present study focuses on the influence of classroom halo effects on teachers' CEFR proficiency level judgements by comparing teacher judgments and students' English marks. A multilevel model of diagnostic competence is presented to assess to what extent the rank and level components are influenced by teachers' familiarity with and use of the CEFR guidelines when judging student proficiency.